ACE-128/64 User's Guide

by Craig Bruce -- for Release #16 -- February 9, 1997.

1. INTRODUCTION

ACE is an operating system for the Commodore 128 and Commodore 64 that provides a Unix-like command-shell environment. All ACE programs will run on either a C128 (in 128 mode) or a C64. BTW, "ACE" means "Advanced Computing Environment" (well, advanced for the 128/64).

This release contains the following improvements over the previous release:

This distribution consists of the following files. System files:

ace              - the kernel bootstrapper; runnable from either 64 or 128 mode
ace128           - the kernel for the C128
ace64            - the kernel for the C64
config           - the configuration-initializer program
.acerc           - the system configuration - this is data, not an executable
config.edit      - configuration-editor program (written in BASIC)
acechr-standard  - standard ACE character set (special graphic characters)
acechr-commodore - regular Commodore character set
acechr-iso-ace   - ISO 8859-1 character set, with ACE 4-bit images
acechr-iso-nova  - ISO 8859-1 character set, with Novaterm 4-bit images
acechr-iso-wide  - ISO 8859-1 character set, with Novaterm-"Wide" 4-bit images
acechr-iso-short - ISO 8859-1 character set, with Novaterm-"Short" 4-bit images
acechr-ansi-ace  - ANSI character set, with ACE 4-bit images
acechr-ansi-nova - ANSI character set, with Novaterm 4-bit images
acechr-ansi-wide - ANSI character set, with Novaterm-"Wide" 4-bit images
acechr-ans-short - ANSI character set, with Novaterm-"Short" 4-bit images
acechr-ans-perry - ANSI character set, with "Perryfont" :-) 4-bit images
acekey-qwerty    - regular qwerty key matrix (also built in)
acekey-dvorak    - Dvorak key matrix
sh               - the command shell (really, an application prog)
.ashrc           - the ACE-command-shell auto-execution shell script

Application programs (explained in Section 6.3):

cp          - copy files
rm          - remove files (scratch)
mv          - rename files (named for Unix "mv"=="move")
mkdir       - create a new directory (flat name)
rmdir       - remove an existing empty directory (flat name)
wc          - count words, lines, characters of files
grep        - search for a substring in files (from Unix "grep")
tr          - translate from one character set to another
sort        - sort lines of files
wrap        - wrap lines longer than 75 characters
date        - display current date and time
forty       - switch to 40-col screen, slow mode
eighty      - switch to 80-col screen, fast mode on 128, or soft-80 on 64
read        - read files (for testing)
mem         - display available dynamic and transient-program-area memory
hello       - dumb little "hello world" example program
window      - set the current window dimensions
acechr      - characterset loader
keymat      - key-matrix loader
head        - display the first N lines of a file, donated by Jake Hamby
jif         - display the current jiffy-clock time
mousetest   - mouse/graphics demo program

more        - full-screen file viewer
uuencode    - encode files into uuencoded format
uudecode    - decode files from uuencoded format
bcode       - encode files into BCODE format
unbcode     - decode files from BCODE format
crc32       - display CRC-32 *B* values for files (new standard)
crc32a      - display CRC-32 *A* values for files (old standard)
kar         - KAR (Kevin's ARchiver) file archiver (all-text format)
unkar       - KAR (Kevin's ARchiver) file dearchiver
vbm         - VBM bitmap-file viewer
vbmpr       - VBM bitmap-file (v2 only) printer for Epson-compatible printers
as          - one-pass assembler
term        - simple VT-100 terminal-emulation program
fx          - custom File eXchange (upload/download) program
z           - ZED text editor

These binary programs are supplied in BCODEd archive format, in two separate files: one for system files and one for application files (one file would be too big for some systems). The "unbcode" program included here will decode this format of archive, but this is a Catch-22, so you will have to either use a previous release of ACE to decode this release, or you'll have to get the C-language "unbcode" program for Unix and MS-DOS. I used to distribute the binaries in uuencoded format, but I have switched to BCODE format so that people will not accidentally corrupt their downloads (and for political reasons). The files may also be available in ".SFX" format too, sometime. In the future, I may be making distributions in ".CSX" (Craig's Self-eXtracting) format, which, of course, will be technologically superior to ".SFX".

Note that the "ace128" and "ace64" programs are functionally identical, except that one is set up for the 128 and the other for the 64. Thus, all of the appication binary programs will work with either "ace128" or "ace64". LOAD and RUN the "ace" program and it will load the correct "kernel" for your computer. Or, you can change the first line of the "ace" program to load a different system configuration and save it with a name like "ace-bigmem" or something, and run that when you want to use the alternate system configuration.

The Buddy- and ACEassembler source code files are also publicly available in ".KAR" format. Most smaller programs are in Buddy format (except for the kernel itself) and most bigger programs are in the ACEassembler format. You should note that, with the exception of conditional and macro assembly, ACEassembler format is pretty much a superset of Buddy format. See the "aceNN-files.doc" documentation file for a list of the various files that are available.


2. USING THE SYSTEM

When ACE starts, it loads and executes the command shell (among other things), gives you a prompt and waits for you to give it a command. A command has the following format:

programname arg1 arg2 ... argN

The programname can be any of the following built-in commands (covered in Section 6.1):

echo       - print the given arguments to stdout
clear      - clear the screen
cls        - same as "clear"
dir        - clear the screen and give a long-form directory listing
d          - same as "directory", but no clear screen
ls         - give a multi-column short-form directory listing
clsl       - combination of "cls" and "ls"
cd         - change the current working device/directory
cat        - display the named files to stdout
exit       - exit from the command shell (perhaps back to BASIC)
x          - same as "exit"
dos        - give a Commodore dos command to the current device (OPEN1,dv,15..)
@          - same as "dos"
path       - set the path to search for external programs
sh         - invoke the shell again as a sub-shell

or programname can be for any of the external programs provided with this distribution. You'll have to forgive my personal taste in command names and abbreviations (until the "alias" shell feature is finally implemented).

2.1. INPUT/OUTPUT REDIRECTION

The three Unix standard files are supported:

stdin    - where the default input comes from (usually the keyboard)
stdout   - where the default output goes to (usually the screen)
stderr   - where error messages are sent to (usually the screen)

To temporarally redirect these standard file streams for the execution of a command, you can use the following incantations on a command line:

<infile     - redirect stdin - input taken from "infile"
>outfile    - redirect stdout - output put into file "outfile"
>>outfile   - redirect stdout - same as ">" but the output is appended to file
>&errfile   - redirect stderr - error output is put into "errfile"
>>&errfile  - redirect stderr - error output is appended to file "errfile"

Do not put a space between the redirection symbol(s) and the file name.

2.2. PATHNAMES

Whenever you specify a file, you use a "pathname". Pathnames have the following optional parts:

[device:][ramlink-directory:][filename]

Device names are set by the user in the configuration file, but the factory defaults are:

"a:"  - Commodore disk device #8 - input/output
"b:"  - Commodore disk device #9 - for if you have >1 drive
....  - Commodore disk devices #10 to #16
"j:"  - Commodore disk device #17 - a disk drive
"k:"  - Custom device driver: the keyboard (or screen)
"m:"  - Custom device driver: Ramdisk
"n:"  - Custom device driver: "null" device
"p:"  - Commodore device #4 - the printer, with SecAddr 7 - output only
"q:"  - Commodore device #4 - the printer, with SecAddr 5 - transparent mode
"s:"  - Custom device driver: the screen (or keyboard)
"u:"  - Custom device driver: user-port inter-machine network/par-print cable
"x:"  - Custom device driver: modem ("to the eXternal world") (SwiftLink-232)
"z:"  - Custom device driver: Ramdisk - intended for storing executables
".:"  - the "current" disk device

CMD RAMLink (or CMD HardDrive) directory names have the following formats:

//dir/:            - a subdirectory of the root directory
/dir/:             - a subdirectory of the current directory
4//dir/dir/dir/:   - a sub-path of the root directory of partition #4
/dir/dir/dir/:     - a sub-path of the current directory

And filenames have the usual Commodore format of 1 to 16 characters.

Thus, the following are valid pathnames for files:

k:                   - the keyboard for input
p:                   - the printer for output
b:file1              - "file1" on disk device #9
.:file1              - "file1" on the current disk device
file1                - "file1" on the current disk device
/dir1/:file1         - "file1" in the RamLink subdirectory "dir1", cur. device
a://dir1/dir2/:file1 - "file1" in the RamLink subdir "//dir1/dir2", device #8

And the following are valid pathnames for directories:

a:             - disk device #8 current directory
.:             - current disk device's current directory      
.://dir1/:     - "dir1" off the root directory of the current RamLink device
/dir1/dir2/:   - subdirectory "/dir1/dir2" of the current RamLink device

Note that a directory name always ends with a ":".

You may append a ",p" or ",s" or ",u" to a filename to specify whether a PRG, SEQ, or USR file should be accessed/created. By default, ACE will create SEQ files.

BTW, to generate an EOF for keyboard input, simply press Control-D. Only do this at the beginning of a blank line.

2.3. COMMAND-SHELL ARGUMENTS

Arguments that contain spaces must be put into quotes. Multiple quoted strings can be placed side-by-side to produce a longer string. The following are examples of valid command-shell arguments:

hello                                  -  hello
'hello'                                -  hello
"hello there"                          -  hello there
'hello there'                          -  hello there
'she said, "how'"'s that"'"'' to me.'  -  she said, "how's that" to me.

Command shell arguments are separated by spaces or tab characters.

2.4. EXTERNAL-COMMAND SEARCH PATH

The "path" command sets or displays the current search pathnames for external programs. By default the paths to search are "z:" and "a:". The path consists of multiple directory names to be checked, in order, for each binary executable or shell script that you give that does not have a pathname prefix.

2.5. WILDCARDS

Unix-style wildcard expansion is supported. When you enter an argument with an asterisk in the filename component of the pathname, the command shell will automatically expand that name into an argument for each file in the specified directory that matches that pattern. The expanded arguments are then passed onto the command you are invoking as if you had typed them all in yourself. For example:

ARGUMENT            EXPANSION
--------            ---------
*                   file1 prog1,p prog2,p
ch*                 chess,p chinese_checkers,p
*.bin               main.bin,p data.bin anagram.bin
a*n                 anagram.bin an another_plan
b:*.bin             b:main.bin,p b:data.bin b:anagram.bin
c://games/:a*.bin   c://games/:acrobat.bin,p c://games/:acrodata.bin

You'll note that program files are expanded to include a ",p". If a pattern does not expand to anything, an error message is displayed and the shell command is not executed. You'll have to cursor-up and change the command. Your filename pattern can include only one asterisk (anywhere in the name).

Some example uses of wildcard expansion with the provided utilities follow:

cp b:* a:
cp //games/c64/:chess*.bin somefile b://games/:
wc *.asm *.c

3. SYSTEM CONFIGURATION

The program entitled "config.edit" is used for editing the system configuration. The system will be configured according to the data in the file ".acerc" every time it starts up. Note that ".acerc" is a loadable binary PRG file; it is not in text format and is not meant to be edited with a text editor.

The following data is included in the ".acerc" file:

OFF  SIZ  DESC
---  ---  ----
$00  128  device descriptors, 32 entries of four bytes each.
          [For each entry, offsets: 0=device driver type, 1=device address,
           2=secondary address, 3=flags.  Described further below.]
$80    1  ramlink device number
          [The kernel device number of your RAMLink.  The default RL device
           number is 16.]
$81    1  ramlink last logical bank allowed to use plus one (norm 255)
          [For the RAMLink memory partition (next section), the maximum
           number of 64K chunks that can be used for dynamic memory.]
$82    4  real-time clock devices to check [4], 255=unused, 254=SmartWatch
          [These are the kernel device numbers of CMD disk drive units that
           have a built-in real-time clock to check for the current time.  If
           the first entry fails, then the second will be tried, etc., until
           the fourth entry is tried.  If all devices fail to return a time,
           then the default date is used (next).  A value of 255 in an entry
           means to try the next entry.  A value of 254 in an entry means to
           try to read the time from the SmartWatch device plugged into
           joystick port #1.  ACE uses the TOD clock of CIA#1 to keep time.
           The date is stored in a regular memory field and is not rolled on
           a 24-hour TOD clock wrap-around.]
$86    1  screen saver activation time, in minutes (norm 10)
          [The screen will go black when the screen saver is activated, after
           a period where you have not pressed any key for the specified time,
           until you press a key (including the any of the shift keys).  If
           you press any character key, that key will appear in your input.
           Normal processing will continue in the background, while the screen
           saver is active, including printing to the screen.  This time is in
           minutes.  A value of zero means to disable the screen saver.  The
           screen saver is now active for the 40-column and 80-column
           displays.]
$87    1  RTS assertion-to-modem-acceptance delay period (norm. 40)
          [This value gives a "fudge factor" for the SwiftLink driver for
           controlling the hardware flow control.  Since Commodore computers
           cannot do disk I/O and process SwiftLink interrupts at the same
           time, it is necessary to turn interrupts off during I/O.  This
           means that if more than one character shows up while interrupts
           are disabled, then data will be lost.  The fudge factor is the
           period that ACE delays between asserting the RTS flow-control
           signal and disabling interrupts.  The value has no particular
           meaning, just the number of times that a particular busy-waiting
           loop in the SL driver is executed.  If you are losing occasional
           characters during buffer capturing in the terminal program and
           you have the modem configured properly for RTS/CTS flow control,
           then you might try increasing this value to see if that solves
           the problem.  With my USR 28.8 modem, a value of 10 works just
           fine, but I've fudged the fudge to be safe here.]
$90   12  default date and time YY:YY:MM:DD:HH:MM:SS:TT:TW:GG:gg:AA
          [The default date to use if attempts to access the current time
           from CMD disk devices/SmartWatch fail.  Format is 24-hour BCD.
           All four digits of the year are given.  The "TT" field is where
           you put the _hundredths_ of seconds (i.e., the tenths go into the
           upper digit).  The "TW" field is where you put the day of the
           week: 0 means Sunday, 1 means Monday, ..., 6 means Saturday, and
           7 meand "unknown".  The "GG" field is where you put the number of
           hours that your time zone is off from GMT.  Negative values are
           entered by adding 80 to the number of hours (setting the high bit
           of the BCD value).  For example, EDT (where I am) is off by -4
           hours from GMT, so I would enter 84.  A value of 99 means
           "unknown".  The "gg" field is where you enter the number of
           minutes you are off from GMT, if you are not off by an even
           number of hours.  This is always a positive value.  The "AA"
           field is where you enter the accuracy of your clock with respect
           to the actual real time.  These time-zone/accuracy fields are
           used even if you pull the time from a CMD/SmartWatch device, so
           set the accuracy according to where the time will usually
           come from.  The accuracy will be interpreted as 2^AA in
           milliseconds, so a value of 10 would mean +/- about a second.  A
           value of 99 means "unknown".  Or, if you don't want to bother,
           it's not really very important that you fill this timezone/
           accuracy information in.  The factory-set value of this field
           is 12am, Sunday, Jan 1, 1995., with unknown timezone and
           accuracy.]
$9C    4  String: name of your time zone: up to three chars plus null
          [This is added just for officialness.  The default value is "XXX",
           which means 'unknown'.]
$A0    1  C128 bank1 start free page (norm $04)
          [This field and the next define the pages of RAM1 that ACE is allowed
           to use.  This must include at least one page.]
$A1    1  C128 bank1 last free page plus one (norm $ff)
$A2    1  C128 expanded internal memory type
          [Not currently used.]
$A3    1  C128 bank0 last allowed free page plus one (norm $ff)
          [This is the highest page, plus one, on RAM0 that ACE is allowed to
           use.  You can set this to protect a program that you wish to
           attempt to use with ACE (good luck).  There is no minimum page that
           ACE is allowed to use; it takes whatever it wants below $6000.]
$A4    1  C64 soft-80 non-REU _minimum_ prescroll amount (norm 5)
          [This will make it so that each "write" system call that prints data
           to the screen that causes the screen to scroll will make the screen
           scroll by at the given number of lines, even if there isn't enough
           data to fill the scrolled-up number of lines.  This makes the
           scrolling action a little uglier but N times more efficient for
           programs that print data one line at a time, like "ls".]
$A5    1  C128 last internal bank allowed to use above 2, plus one (norm 8)
          [For expanded internal memory (a la TwinCities-128), this sets the
           high limit on the banks that ACE is allowed to use.  A value of 2
           means that ACE is not allowed to use it at all.  There is no low
           limit on this because it caused too many programming problems.]
$A6    1  C128 first REU bank allowed to use (norm 0)
          [This and the next field define the minimum and maximum (plus one)
           REU bank numbers that ACE is allowed to use.  I included a minumum
           because of pleas about Zed having a minimum.  If you set both min
           and max to $00, then ACE will leave the REU memory alone.
           Otherwise, ACE will auto-detect how much you have and will make use
           of as much REU memory as it can (note the default max is 255).]
$A7    1  C128 last REU bank allowed to use plus one (norm 255)
$A8    1  C128 top page of TPA (stack) (norm $c0)
          [This defines that page (plus one) of the top of the application
           program area (TPA).  The bottom is $6000, so a top of $C000 gives
           apps 24K to play around in.  $C0 is the maximum value this field
           can have, since the Commodore Kernal must (for this release) stay
           in context whenever ACE is in use.  The top of this space is also
           used as the "argument stack" for applications.]
$A9    1  C128 VDC default number of rows (norm 25)
          [This option selects the number of rows to display on the VDC screen
           whenever ACE starts up or whenever a user program (like "eighty")
           says to use the default number of display rows.]
$AA    1  C128 VDC number of Kbytes of video RAM (norm 16)
          [What it says.  Valid values for this option are 16 and 64.  There
           will be no problem if your machine really has 64K but you only say
           it has 16K.]
$AB    1  C64 soft-80 screen maximum prescroll for REU-supported scrolling
          [The maximum number of lines to "prescroll" the screen if your
           program makes the "write" system call with multiple lines worth of
           data to display onto the screen.  The cursor will always end up on
           the bottom line of the display.  This option makes the scrolling
           a bit jumpier but much more efficient.  This option is normally
           set to 99, which really means the number of lines on the screen.]
$AC    1  C128 80-col screen maximum prescroll
          [The maximum number of lines to "prescroll" the screen.  The
           factory-set default is 99, which really means the number of lines
           on the screen.]
$AD    1  C128 40-col screen maximum prescroll
          [The maximum number of lines to "prescroll" the screen.  The
           factory-set default is 99, which really means the number of lines
           on the screen.]
$AE    1  C64 soft-80 screen maximum prescroll for software scrolling
          [The maximum number of lines to "prescroll" the screen.  The
           factory-set default is 99, which really means the number of lines
           on the screen.]
$AF    1  C64 40-col screen maximum prescroll
          [The maximum number of lines to "prescroll" the screen.  The
           factory-set default is 99, which really means the number of lines
           on the screen.]
$B0    8  C128 80-col screen color palette: table of eight RGBI codes.
          [This table gives the palette of colors to be used by C128 80-col
           applications.  The meanings of the values stored at the offsets
           are: 0=char, 1=cursor, 2=status, 3=separator, 4=highlight, 5=alert,
           6=border, 7=screen.  The char, border, and screen colors are used
           when the screen driver is initialized.  The border value for the
           80-col screen is currently ignored.  Note that RGBI codes are used,
           even for the VIC chip (for consistency).  The factory defaults for
           char, screen, and border are light grey on black for 80 and light
           green on dark grey with a medium grey border for the 40 (perhaps a
           bit icky).  The other values are chosen accordingly.  The palettes
           for the other displays have the same structure as this one.]
$B8    8  C128 40-col color palette
$C0    1  C64 soft-80 enable mask (norm %10100000)
          [The 128-bit allows the soft-80 screen to be used.  Allowing the
           soft-80 screen costs 12K of RAM0 memory on the C64.  This software-
           implemented bitmap 80-column screen is supported only on the C64.
           On a C128, use the real 80-column screen.  If the soft-80 screen is
           not allowed, then the 12K of memory is made available for far
           memory use (e.g., for ramdisks).  The 64-bit specifies that the
           soft-80 screen is to be entered by default when ACE starts up,
           rather than the 40-col screen.  You can switch between the two
           screens by using the "forty" and "eighty" programs.  The 32-bit
           specifies that the REU is to be used to assist in scrolling the
           bitmap screen if an REU is present.  The cost of doing this is 7.5K
           of REU memory.  The benefit is that the screen will scroll several
           times faster than it will by just using the main processor, which
           is used otherwise.]
$C1    1  C64 last allowed page free plus one (norm $ff)
          [This gives the top page, plus one, that ACE is allowed to use on
           the 64.  Don't set this lower than the top of the TPA area.]
$C2    1  C64 first REU bank allowed to use (norm $00)
          [Like the C128 settings, you can set the usage for the REU memory.]
$C3    1  C64 last REU bank allowed to use (norm $ff)
$C4    1  C64 expanded internal memory type
          [Not currently supported.]
$C5    1  C64 end expanded internal memory banks plus one (norm $04)
          [This field is currently ignored.]
$C6    1  C64 top page of TPA (stack) (norm $a3)
          [Top of the TPA for the 64.  You can set this between $61 and $d0,
           but be sure not to collide with the stuff in high memory (see the
           memory map earlier in this document).  I set the default here
           lower than it needs to be so that a stock C64 with the soft-80
           screen configured will have enough memory to load the command
           shell onto the ramdisk.  If you have expanded memory, then you
           should set this to $c0 to get maximum application performance
           (from bigger data buffers).]
$C7    1  Video type: NTSC (0) or PAL (1) (default: 0)
$C8    1  key repeat delay (norm 20)
          [The number of jiffies between when you press a key the first time
           and when it starts repeating.]
$C9    1  key repeat rate (norm 3)
          [The number of jiffies between each repeat of a key while you are
           holding it down.]
$CA    1  console color enable default (norm $80)
          [This is used to enable what is normally printed on the console
           screen: characters, colors, and/or attributes.  All applications
           that need to use colors will enable and restore the console
           colors by themselves, so there is no need to have them enabled
           all the time.  The default is to have only characters enabled
           (not colors/attributes) because this allows it to operate twice
           as quickly for operations like scrolling.]
$CB    1  input line scrollback buffer line count (norm 5)
          [The number of previous lines to save so that you can scroll back
           through previous input lines in order to edit them.  Each line
           of buffer space requires 256 bytes of far memory to store.
           You MUST specify at least one line, or the system will crash in
           all sorts of weird and wonderful ways (this is a bug, not a
           feature).]
$CC    1  controller port 1 device
          [Not currently implemented.]
$CD    1  controller port 2 device
          [Not currently implemented.]
$CE    1  C128 VDC maximum number of rows to display (norm 51)
          [This setting gives the maximum number of rows that you want your
           screen to display.  Some programs will ask for this maximum setting
           (like "eighty 255").  You should set this to the maximum number of
           (interlaced) lines that will fit on your display.  The value 51 is
           the absolute maximum: the maximum that hardware will support.]
$CF    1  C128 VDC "crossover" number of display rows (norm 28)
          [This setting gives the number of VDC display rows which will be the
           lowest setting that will be displayed in interlace mode.  The
           interlace characters are approximately half as high as the regular
           characters, so you will be able to see more on your screen.  The
           factory-set default is probably good for a TV, but you can see
           what works for you.  I have a 1902a monitor, and I can display
           30 lines in regular characters (the maximum the hardware allows),
           so I set the "crossover" value to 31 for myself.  Note: I don't
           know how well these interlaced characters will work on non-NTSC
           machines, or on non-1902a's, but you can try them for yourself.
           If they don't work, then you can just set this option to be larger
           than the maximum number of VDC rows to display (previous option),
           and you'll never have to look at interlaced characters.]
$D0    8  C64 80-col color palette
          [For the bitmapped hi-res 80-col screen, which is not yet
           implemented.]
$D8    8  C64 40-col color palette
$E0    1  The RAMLink-RAM partition number (norm. 31)
          [See the Dynamic Memory section below.]
$E1   13  String: The RAMLink-RAM parition name (norm. "rl-ram")
$EE    1  The RAMLink-Indirect-REU partition number (norm. 30)
$EF   17  String: RAMLink-Indirect-REU partition name (norm. "indirect-reu")
$100  32  initial/home current directory string (default "a:")
          [Immediately after booting and before calling the shell, the kernel
           will do a change directory to the null-terminated string given
           here.]
$120  32  String: user-definable keymatrix file, or null (norm. "")
$140  64  String: default executable search path (def. "z:", "a:", ".:")
          [The paths to use to search for executable programs.  Each directory
           name is a null-terminated string, and the list of paths is
           terminated by an empty string.]
$180  64  Configuration-file search path (def. "z:", "a:")
          [Not currently used.]
$1C0  32  Temporary-file directory name (def. ".:")
          [The directory to use to store intermediate/temporary files.]
$1E0  32  Name of character set to load when booting up (n."acechr-commodore")
$200   -  SIZE

The offsets from $00 to $7F contain 32 four-byte fields, which are used to define the devices in the system. These fields will correspond to device names "@:", "A:", "B:", ..., "Z:", "[:", "\:", "]:", "^:", and "_:" (forgive the non-letter device names). The four fields will be defined as follows:

0 device driver type (0=Kernal non-disk, 1=Kernal disk, 2=console, 3=null,
  4=ramdisk, 5=userport, 6=swiftlink/turbo232, 255=empty)
1 device primary address
  (SwiftLink/Turbo232: I/O page of hardware: $de, $df, or $d7)
2 device secondary address
3 flags
  (KernalDisk: $80 for a disk will means that it has a CMD Real-Time clock)
  (UserPort: $00=use raw communication, $80=use packet-oriented communication,
           $40=use PA2 raw comm (use this w/GEOcable), $C0=use PA2 packet comm)
  (SwiftLink: below)

For the SwiftLink or Turbo232 device (hereafter referred to as just "SwiftLink" unless noted), the "primary address" field contains the I/O page of the swiftlink chip (normally $de, but you can use $df or $d7 as well). The "secondary address" field is no longer used, as the receive buffer has been fixed at 256 bytes.

The "flags" field for the swiftlink should be set as follows. The 128 bit should be set to "0" if you want your modem parameters to be "8N1" or set to "1" if you want "7E1". No other word-length/parity/stop-bits settings are supported. The 64 bit should be set to "0" if you have a normal (double- speed) clock crystal (what CMD ships) or a Turbo232, or set to "1" if you have a hacked (standard-speed) clock crystal (1.8432 MHz). An unhacked SwiftLink only goes up to 38.4kbps, and a hacked one will go at 115.2kbps (but not 38.4kbps). The Turbo232 supports all of the speeds up to 230.4kbps. There is no flag to indicate the Turbo232 since it is auto- detected. The lower four bits should be set to select the baud rate, according to the following table. The factory-set default is to 2400 baud with 8N1 and a non-hacked SwiftLink ($06).

bits   hex   dec      baud
----   ---   ---    ------
0000     0     0        50
0001     1     1       110
0010     2     2       134.5
0011     3     3       300
0100     4     4       600
0101     5     5      1200
0110     6     6      2400
0111     7     7      4800
1000     8     8      9600
1001     9     9     19.2k
1010     a    10     38.4k
1011     b    11     57.6k
1100     c    12    115.2k   (available on Fast C128 and SuperCPU)
1101     d    13    230.4k   (available on SuperCPU only)
1110     e    14    460.8k   (not implemented, but theoretically attainable)
1111     f    15    921.6k   (    by the SuperCPU)

If you don't want to waste memory on SwiftLink transmit and receive buffers in your configuration, then just remove the device entry for the swiftlink (normally device slot "x:") by setting the device type to 255 (empty). You don't have to worry about any memory-bleed problems with this device, since ACE will touch its I/O registers and intialize the SwiftLink chip only if you open a file to the device driver (i.e., use the "term" program).

To spare you the agony of editing this binary configuration manually, the BASIC program "config.edit" can be used instead. Run it from BASIC, not from inside of ACE. In fact, you should run this before running ACE the first time to set up the configuration.

The program provides a full-screen interface. Move the cursor among the fields on each page and among the pages to set the values. All values are in decimal (except the strings). Then save the new configuration, exit, and run ACE. If you screw up the new ".acerc", the previous one will be available in ".acerc.bak".


4. DYNAMIC MEMORY

After you have configured ACE for your system, if you have a RAMLink, you will have to configure it for ACE if you want to use RAMLink RAM or indirect REU access. The way that ACE detects these types of memory is via the RL-DOS partition table. For RAMLink RAM, ACE will check for partition number 31 being a Foreign Mode (Direct Access) partition with the name "rl-ram". (You can change the partition number/name in the configuration if you wish). If it is, then ACE will get the information for that partition to determine the size and start address (in RL memory). It will then check the limit for usage of RL-RAM in the ".acerc" file, and adjust the size it can use accordingly, before initializing the memory. To set up this partition on your RAMLink in the first place, refer to your RAMLink documentation and use the tools program provided with it.

Using REU (Ram Expansion Unit) memory with ACE is pretty easy; you just make sure it is plugged into the computer when ACE is started. ACE will auto-detect the size of the REU and then check the configuration for limitiations on REU usage.

If you have your REU plugged into your RAMLink in the RAM port (rather than the pass-through port), and you have the Normal/Direct switch thrown to the Normal position, then your machine cannot access REU memory in the usual way. The only way to access it is to go through the RAMLink. ACE will look for partition number 30 being Direct Access and named "indirect-reu" for this purpose. (You can change this partition number/name in the configuration). If your Normal/Direct switch is in the Direct position, then ACE will use the REU directly and will ignore the "indirect-reu" partition. Do not change the position of the Normal/Direct switch while ACE is in action.

The tricky part here is in configuring your RAMLink. You have to make sure that the memory allocated to the "indirect-reu" partiton is the memory of the REU. RAMLink memory starts from $000000 and goes up to $FFFFFF. REU memory will be at the very front of this memory (from address $000000), and the internal RAMLink memory will follow immediately after this. For example, if I had a 512K REU and an 8 Meg RAMLink, my REU memory would cover RL addresses $000000-$07FFFF, and my internal RL memory would cover RL addresses $080000-$87FFFF. When partitioning the device, partitions are assigned memory from lower addresses to higher addresses. So, starting with an empty RL (no partitions), you must create the "indirect-reu" partition first, followed by any RL-DOS partitions and the "rl-ram" partition. You must also make sure that the "indirect-reu" partition is the same size as your REU. 512K is 2048 blocks. A note for deleting RL partitions: delete the ones that were last allocated first.

You have the option of installing or not installing either of these partitions. If either is missing, ACE will simply work without it. You'll want to be careful about throwing the Direct switch if you don't have your REU "protected" with an "indirect-reu" partition. (With other REU applications also).

The various types of memory give the following performance under ACE:

type            bandwidth   latency
-------------   ---------   -------
REU             1,007,641      65.8
REU thru RL     1,007,641      77.8
RAMLink           105,792     199.2
RL with REU       372,827     319.8
internal RAM0     120,181      44.2
internal RAM1      80,283      56.3

The bandwidth is in bytes/sec and the latency is in slow ticks (~microseconds). To determine how much time it will take to perform a specific request, take the number of bytes you want to transfer and divide it by the bandwidth, multiply the result by 1,022,727 (NTSC) and add the latency. This will give you the transfer time in slow ticks.

For the types: "REU" is the REU being accessed directly and "REU thru RL" is the REU being accessed through a RAMLink: the REU must be plugged into the RAM port of the RL and the Normal/Direct switch must be in Normal position and the "indirect-reu" partition must be set up. "RAMLink" is the RL partition "rl-ram" being accessed without REU assistance and "RL with REU" is the RL partition "rl-ram" being accessed when the assistance of an REU; the REU must be plugged into the RAM port and the Normal/Direct switch can be in either position.

For internal memory, the 64 has only one 64K internal bank, whereas your 128 can have either 2, 4, or 8 (128K, 256K, or 512K). The internal 128 memory above 128K is accessed according to the articles in TwinCities-128 Magazine.

When ACE starts, it determines the size of internal and REU memory by writing special values in the same locations of each bank and looking for readback failures or wrap-arounds. However, after testing a bank, the original contents of the test locations are restored. So, the testing process is completely non-destructive.


5. DEVICES

5.1. COMMODORE CHARACTER DEVICES

These are regular Commodore character-oriented devices, which really only includes the printer right now. The standard Kernal calls are made for all I/O. These devices will behave the same way they always have.

5.2. DISK DEVICES

5.2.1. COMMODORE DISK DEVICES

Regular Commodore disk units are accessed in the same way as character- oriented Commodore devices, except that disk devices also support special operations such as directory listings. The standard Kernal calls are used and so are the standard Commodore-DOS incantations for operations such as deleting (scratching) a file. You can use the "dos" command of the command shell to send special Commodore-DOS commands directly to these devices.

5.2.2. CMD DISK DEVICES

For CMD disk devices, support has been added to the kernel to request a "long-form" directory listing, including the date and time of last modification of all files. This allows ACE to pass this information onto application programs that request a directory listing from the CMD device. Special support is also included for interpreting directory and pathnames. The rest of accessing CMD disk devices is handled exactly the same as for regular Commodore disk devices.

5.2.2. RAMDISK DEVICE

The Ramdisk, as currently implemented, has one major restriction: flat filenames. I.e., subdirectories are not currently supported. To make up for this deficiency, you can have as many ramdisks active in the system as you like. Setting a device to be a ramdisk in the system configuration is very easy: just change the device type code to the ramdisk type (code 4). When the system initializes, the kernel will scan the device configuration and initialize every ramdisk that you specify. Each initialized empty ramdisk costs 512 bytes of far memory storage.

All of the standard disk device operations are supported for ramdisks, except, of course for "mkdir" and "rmdir", since subdirectories are not implemented. The operations include: open for read/write/append, read, write, binary-load (for loading programs), remove, rename, directory open & read, change directory (to device), "devinfo", and "isdir" (see the ACE-128/64 Programmer's Reference Guide for further descriptions of these operations).

The factory-default configuration for ramdisks is to have two of them: devices "m:" and "z:". The intention is that you will use device "z:" for storing your often-used programs and "m:" for your general storage. You can store executables on a ramdisk and they will load very quickly. For this reason, the factory-default executable search path is "z:,a:", meaning that device "z:" will be checked before device "a:".

To get good use out of the ramdisks, it is recommended that if you have a 64 then you also have an REU or some other memory expander. Without any memory expansion, if you have disabled the soft-80 screen you will have 16K of far memory for storing ramdisk data and if the soft-80 screen is enabled, you will only have 6K. With an REU, you can use all of the REU memory for a ramdisk if you wish. On an unexpanded 128 you will have 70K or so for ramdisks. Note that because of the "far memory" organization of ACE, the far memory can be used to store ramdisk data and any other type of far memory storage. Memory utilization is dynamic so you don't have to reserve large chunks of far memory exclusively for a particular purpose.

As advertised at the top of this document, the ramdisk driver is capable of delivering a peak reading speed of about 1 megabyte per second. This is for reading a big file that was written to the ramdisk in large chunks, where the file is stored completely in REU memory. For a similar file stored completely in RAMLink memory, the reading speed will be around 56K/sec. The writing speed of files will be approximately the same as for reading files, because of the way the data is organized: the limiting factor is the data transfer speed rather than system overhead. The above figures are for a Fast-mode C128. You should get comparable REU performace from Slow-mode or a 64 and about half the performance in Slow mode from a RAMLink.

I don't want to go into too many details, but to get such high performance, the ramdisk driver uses variable-sized disk blocks. Each block can be between 256 bytes and 64K in size and includes 6 bytes of control information. When you perform a write operation, the kernel will write the data out in the largest blocks possible without wasting space. This way, when the data is read back in using a large "read" operation, very little control overhead is needed and the data can be transferred to internal memory in large chunks, and the aggregrated per-byte accessing cost is minimized, almost to the raw hardware-accessing speed.

Future expansion possibilites for this device include implementing subdirectories and implementing new types of memory which retain their contents between runs of ACE (but not power interruptions) so that you can have a "permanent" ramdisk similar to the way that RAMLink partitions work. As it is now, all ramdisks are erased when the system starts, so you have to copy necessary files to the ramdisks every time you reboot.

5.3. SCREEN

5.3.1. NORMAL SCREENS

The screen has a custom device driver for the 40-column (VIC) screen of both the C128 and C64 and the 80-column (VDC) screen of the C128. The bitmap-implemented soft-80-column screen for the 64 is described in the next section. Because of the way that the system has been designed, new screen drivers just easily slip into place (well, maybe it's not quite that easy...).

The custom screen driver includes support for the basic text-output operation, as well as special full-screen accessing calls to allow for the simplified and standard implementation of full-screen programs, such as a text editor. Such a program would be able to work on the 40-column C64 screen, the Soft-80 C64 screen, as well as the 80-column C128 screen, with no modification. The Commodore Kernal includes very little support for full-screen applications (only numerous control character codes).

For the regular output, only the screen characters and not the colors are used (normally), which allows scrolling to be twice as fast. Outputing characters is also faster because fewer control characters are supported, no translations between PETSCII and screen codes needs to take place, and operations are optimized for speed (rather than ROM size). The display character set has been rearranged to correspond to the PETSCII character codes, except for the "Commodore" characters. The graphics characters have been re-thought for applications. The screen driver also includes basic support for user-windows, which will be taken advantage of in future applications.

A prescrolling feature has been implemented to cut down on the number of times the screen has to be scrolled in displaying text, to increase the display speed.

5.3.2. BITMAPPED 80-COLUMN SCREEN FOR THE 64

This screen is implemented with a VIC bitmap and 4x8-pixel characters. The screen maps into memory under the Commodore Kernal ROM. The attribute bits of color values act as background color for color cells, and the color cells cover two character spaces, because of the VIC hardware.

Er, I should mention about the character set. The one I have I came up with for a VIC-20 40-col screen program a long time ago but it may not be ideal for the smaller pixels of the 64. I have selected the default screen colors (black on gray) to display the characters clearly. It works best if you turn the brightness up on your monitor, to cut down on the pixel distortion of the 64 display. If you come up with a better character set or screen color combination, please let me know. The format of the character set is explained in the "aceNN-tech.doc" document.

5.3.3. GRAPHICS SCREENS

The kernel has been extended to include basic support for 320*200 monochrome graphics on the 64 and 640*200 and 640*491 (64K only) using the VDC display of the 128. The 320*200 and 640*491 displays have a pixel aspect of 1-to-1 and the 640*200 display has a pixel aspect ratio of 2-to-1. The aspect ratio is made available to application programs so they can correct it, if they so choose. The basic support the kernel provides includes only getting in and out of graphics mode, filling the screen with a given byte value, and loading the bytes of a display line. A number of extensions are possible, but I'd like to keep it simple to keep down the kernel size.

5.4. KEYBOARD

A custom keyboard scanner has been added also. It supports a three-key rollover as discussed in C= Hacking Net Magazine Issue #6. The key matricies will be extended to include a number of standard control characters for things like "page up," etc. Key scanning has been completely taken over to implement the three-key rollover, and to avoid interference with the joystick in port #1.

There are a few new keyboard controls. To temporarily pause a listing going to the screen, press the CONTROL key. Output will resume when you release the key. For the C128, the NO SCROLL key is supported in the normal way. On the 64, to achieve the same effect, press the RUN/STOP key while holding down the CONTROL key to pause output until you explicitly re-enable it. To do this, just press NO SCROLL (128) or CONTROL-STOP (64) again. On the 128, the CAPS key is supported in the normal way (with CAPS-Q fixed), and to activate caps lock mode on the 64, press COMMODORE-STOP, and press it again to release caps lock mode. The key delay and repeat rates are not user- definable right now, but they will be. Also, function keys will be application-definable (where the command shell can be considered an application). Something that you may find odd is that the cursor color can be different from the character color. Deal with it.

Full input line editing is supported. Lines may be up to 248 characters long, including the carriage return. You can delete the character before the cursor by typing DEL. You can use the cursor LEFT and RIGHT keys to move the cursor on the current input line and any characters you type will be inserted before the character that the cursor is on. CO-LEFT and CO-RIGHT (on the 128 with the upper cursor keys) move the cursor to the beginning and end of the current line. CT-A and CT-E do the same thing (after Unix). When you wish to generate an EOF (end-of-file) signal from the keyboard, press CONTROL-D. This will only work on an empty line; otherwise, you will get the CT-D character.

If you wish to edit and re-enter a previous line, press the cursor-UP key when the system prompts you for an input line. This will recall the previous line. You can press cursor-UP and DOWN to scan through all of the scroll buffer lines you have allocated in the configuration. Buffering each line will cost you 256 bytes of far memory.

When you have selected a previous input line, you can edit it or re-enter it just like normal. The instant that you change or enter the line, it becomes the current line. Otherwise, if you don't change a previous line, then you can scroll back down to the current line you were working on before. This is useful for checking some item on a previous line and then continuing with the current line. When you scroll back to the end of the history buffer, the bell will ring if you try to scroll back any farther. Blank lines are not entered in the scrollback buffer. Also, all lines rather than just the command lines are saved (although I may reconsider this later).

Many applications will make use of a number of key combinations, so here is a recommended set of control codes and how they should normally be interpreted by application programs. Note that the keys for "@" to "_", used in association with shifting keys, are "@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_". "CT" means Control, "SH" means Shift, "AL" means Alternate, and "CO" means Commodore. On the C64, Alternate is obtained by holding down the Commodore and Control keys simultaneously, and "CS" below means to hold down the Commodore and Shift keys simultaneously. The "CS" combination is used to make the functions of keys only provided on the C128's extended keyboard available on the C64.

CODE(s)   C128 KEY(s)    C64 KEY(s)     DESCRIPTION
-------   ------------   ------------   -----------
$5c       BritishPound   BritishPound   (\) the backslash character
$5e       UpArrow        UpArrow        (^) the carret character
$5f       BackArrow      BackArrow      (_) the underscore character
$c0       SH-*           SH-*           (`) the back-quote character
$db       SH-+           SH-+           ({) the left-curly-brace character
$dc       SH-BritPound   SH-BritPound   (|) the vertical-bar character
$de       SH-- (minus)   SH-- (minus)   (}) the right-curly-brace character
$df       SH-BackArrow   SH-BackArrow   the house character (DEL in ASCII)

CODE(s)   C128 KEY(s)    C64 KEY(s)     DESCRIPTION
-------   ------------   ------------   -----------
$20-$3f   SPACE to "?"   SPACE to "?"   Regular numbers and punctuation
$40-$5f   "@" to "_"     "@" to "_"     Regular lowercase letters
$60-$7f   AL-@ to AL-_       Alternate keys
$a0-$bf   CO-@ to CO-_   CO-@ to CO-_   Commodore keys
$c0-$df   "`" to HOUSE   "`" to HOUSE   Regular uppercase letters
$e0-$ef   CT-@ to CT-_   CT-@ to CT-_   Control keys

CODE(s)   C128 KEY(s)    C64 KEY(s)     DESCRIPTION
-------   ------------   ------------   -----------
$00                         
$01       CT-RETURN      CT-RETURN      End of file
$02       SH-TAB         CS-R           Backtab
$03       STOP           STOP           Stop some operations
$04       HELP           CS-H           Context-sensitive help
$05       CT-2           CT-2           White
$06       SH-LEFT        CS-B           Word left
$07       SH-LINEFEED    CS-P           Menu exit
$08       CO-DEL         CO-DEL         Rubout character under cursor
$09       TAB            CS-T           Tab
$0a       LINEFEED       CS-L           Menu
$0b       SH-RIGHT       CS-N           Word right
$0c       CO-UP          CS-W           Goto top of document
$0d       RETURN         RETURN         Return
$0e       SH-ESCAPE      CS-D           Window control
$0f       CO-DOWN        CS-Z           Goto bottom of document
$10       CO-LEFT        CS-A           Goto beginning of line
$11       DOWN           DOWN           Cursor down
$12       CT-9           CT-9           Rvs
$13       HOME           HOME           Home
$14       DEL            DEL            Backspace
$15       CO-RIGHT       CS-S           Goto end of line
$16       CT-UP          CS-I           Page up
$17       CT-DOWN        CS-M           Page down
$18       CT-TAB         CS-Y           Tab set
$19       CT-LEFT        CS-J           Page left
$1a       CT-RIGHT       CS-K           Page right
$1b       ESCAPE         CS-E           Escape
$1c       CT-3           CT-3           Red
$1d       RIGHT          RIGHT          Cursor right
$1e       CT-6           CT-6           Green
$1f       CT-7           CT-7           Blue

CODE(s)   C128 KEY(s)    C64 KEY(s)     DESCRIPTION
-------   ------------   ------------   -----------
$80       CT-F1          CT-F1          Function key 9
$81       CO-1           CO-1           Orange/Purple(?)
$82       CT-F3          CT-F3          Function key 10
$83       SH-STOP        SH-STOP        Run
$84       SH-HELP        CS-G           Context-insensitive help
$85       F1             F1             Function key 1
$86       F3             F3             Function key 3
$87       F5             F5             Function key 5
$88       F7             F7             Function key 7
$89       SH-F1          SH-F1          Function key 2
$8a       SH-F3          SH-F3          Function key 4
$8b       SH-F5          SH-F5          Function key 6
$8c       SH-F7          SH-F7          Function key 8
$8d       SH-RETURN      SH-RETURN      
$8e       CT-F5          CT-F5          Function key 11
$8f       CT-F7          CT-F7          Function key 12
$90       CT-1           CT-1           Black
$91       UP             UP             Cursor up
$92       CT-0           CT-0           Rvs off
$93       SH-HOME        SH-HOME        Clear screen
$94       SH-DELETE      SH-DELETE      Insert one space
$95       CO-2           CO-2           Brown
$96       CO-3           CO-3           Light red
$97       CO-4           CO-4           Dark gray
$98       CO-5           CO-5           Medium gray/dark cyan(?)
$99       CO-6           CO-6           Light green
$9a       CO-7           CO-7           Light blue
$9b       CO-8           CO-8           Light gray
$9c       CT-5           CT-5           Magenta
$9d       LEFT           LEFT           Cursor left
$9e       CT-8           CT-8           Yellow
$9f       CT-4           CT-4           Cyan

For the Dvorak key matrix, the following combination of Dvorak and Commodore is used on the basic keyboard:

    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    | _ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | + | - | \ |hom|del|
    +---------------------------------------------------------------+
    |ctrl | @ | , | . | P | Y | F | G | C | R | L | / | * | ^ |restr|
    +---------------------------------------------------------------+
    |stp|shl| A | O | E | U | I | D | H | T | N | S | ; | = | return|
    +---------------------------------------------------------------+
    | C=|shift| : | Q | J | K | X | B | M | W | V | Z |shift| v |-> |
    +---+-----+---+---+---+---+---+---+---+---+---+---+-----+---+---+

All of the keys are moved as a unit, so shifting a key will produce the same result as the corresponding key in the standard Commodore Qwerty layout. The extended keys remain the same. If you want to redefine the key matrix yourself, then look in the "acekey-dvorak.s" for more information. It is an ACE-assembler source file that encodes the translation tables.

5.5 USER-PORT INTER-MACHINE NETWORK DEVICE

The device follows from what was outlined in issue #8 of C= Hacking net magazine. It allows you to send bytes of data from one computer to another, which is all that any network, no matter how complicated, actually does. With this ability, you can write arbitrarily complex distributed applications. Well, before we get too grand, the "network" is currently limited to only connecting two compters together. Here is how the wiring goes if you want to make your own network cable:

Host-A  name/pin                                      pin/name  Host-B
         GND (A)+------------------------------------+(A) GND
        FLAG (B)+------------------------------------+(8) PC2 ***
         PB0 (C)+------------------------------------+(C) PB0
         PB1 (D)+------------------------------------+(D) PB1
         PB2 (E)+------------------------------------+(E) PB2
         PB3 (F)+------------------------------------+(F) PB3
         PB4 (H)+------------------------------------+(H) PB4
         PB5 (J)+------------------------------------+(J) PB5
         PB6 (K)+------------------------------------+(K) PB6
         PB7 (L)+------------------------------------+(L) PB7
         PA2 (M)+------------------------------------+(M) PA2 (or use as PC2)
         GND (N)+------------------------------------+(N) GND
        CNT2 (6)+------------------------------------+(6) CNT2
         SP2 (7)+------------------------------------+(7) SP2
         PC2 (8)+------------------------------------+(B) FLAG ***

Here is the Commodore 128/64 User Port when looking at the back of the unit:

                             111
     (other)        123456789012    top          (edge of)
     (ports)        ------------                 (machine)
                    ABCDEFHJKLMN    bottom

You will need two appropriate connectors and some 14-conductor ribbon cable to build the network. One of my connectors is a 44-conductor connector of the type used with the VIC-20 expansion port that I sawed in half and the cable is some old junk ribbon cable that was lying around that I removed some of the conductors from. Any old junk will do. You're probably best off if your cable is less than two metres long (six feet).

There are two software protocols implemented for transmitting bytes over the network: Raw and Packet. The Raw protocol just sends the raw bytes using only the hardware handshaking. This should be suitable for use with parallel- port printers. The Packet protocol writes three bytes of header information plus the given data for each "write" operation to the device. The header information consists of the value $E6, followed by the low byte of the number of data bytes to follow, followed by the high byte of the count, followed by the data bytes themselves. This protocol allows the other end to know what the packet boundaries are, and packet boundaries are needed for interactive interprocess communication, such as with RPCs (Remote Procedure Calls). The implemented protocol also sends a packet with zero user-data bytes out when you use the "close" system call on the user-port device, so the Packet protocol is also useful for transferring files from one machine to anotherA.

But, since the network is inherently half-duplex (data can only flow in one direction at a time), you must be very careful about coordinating things so that you always have one transmitter and one receiver whenever you are transferring data. If both hosts try to receive or both try to transmit at the same time, they will both deadlock forever (or until you reset them).

As an example, if you wanted to transfer a file over the network, you would enter the following on the receiving computer:

cat u: >file

and the following on the transmitting computer:

cat file >u:

The device operates much like a Unix "pipe". You can also use the "cp" or "bcode" or whatever and you the order in which you start the transmitter/ receiver doesn't matter. The packet size on the network is variable and is defined by the size of write call that the transmitter performs a write operation.

Flow-control handshaking is performed for each byte sent, so the writer will be delayed in the write system call until the receiver has received every last byte of the packet by performing appropriate read operations. This means that the writer will operate synchronously with the reader if the receive buffer (read size) is smaller than the transmit buffer (write size) and that the writer will operate asynchronously (*concurrently*) with the receiver if the receive buffer is larger than or equal in size to the transmit buffer. Concurrency is good. Also, reads will sometimes return "short blocks", blocks with fewer bytes than the read request specified. This is to allow the device to be truly packet-oriented, which can allow client/server-type interactions over the half-duplex communication line.

The maximum transfer rate is currently around 40K/sec. The maximum rate possible, if software were as efficient as possible, would be about 80K/sec with two Fast-mode C128s.

5.6. SWIFTLINK-232 DEVICE

This device driver supports Creative Micro Design's SwiftLink-232 and Turbo-232 cartridges, which are based on the 6551 ACIA chip. The way to configure the operation of this device (receive-buffer size, baud rate, word-length/parity/ stop-bits) was discussed in the System Configuration section. The device will work only from any page-aligned I/O slot where $DE00 is the default.

Here are a couple of notes about the device driver. It will operate flawlessly at 115.2kbps, 57.6kbps, and 230.4kbps on the C128, C64, and SuperCPU-64 respectively. At these speeds, the machine has only about 177 clock cycles (NTSC) per character received. The device driver also implements hardware flow control out of practical necessity. If you are operating at 9600 baud or higher, then it is likely that (a) whatever you're connected to supports hardware flow control (HFC), and (b) that your application won't be able to keep up all of the time. The HFC works flawlessly as far as I have tested. Because of the immediacy of HFC, the device will assert HFC when there are fewer than 8 bytes free in the receive buffer (a small limit) and will release it where there are 64 or more bytes free in the receive buffer.

An unfortunate hardware restriction of the 6551 ACIA is that it cannot transmit data while the HFC is asserted. This makes controlling transmit data more complicated but also makes it so that the RTS/CTS signals simultaneously work according to their standard definitions and also to their newer flow-control definitions. This is okay, since newer high-speed modems usually interpret these signals in the flow-control way and older modems are likely to operate at a baud rate where flow control is not needed. Note that if flow control is ignored by your modem and the receive buffer overflows, then you WILL lose characters. The SL driver collects statistics about this (number of hardware overruns, number of software-buffer overflows, number of bytes sent, number of bytes received).

The SwiftLink driver does not use transmit interrupts. This is because having both types of interrupts is an ugly problem and may be too much for the processor to keep up with. Instead, the SL driver uses polled transmission. In the context of a terminal program, this is normally no real problem, since normally only one or a few bytes are transmitted at a time (with each keystroke). In the event that HFC is asserted when the driver goes to transmit a byte, it will put the byte into the transmit buffer and return without transmitting the byte. This is because the system would deadlock if it waited for a transmit-ready signal, since it will never get one as long as HFC is asserted. Control is returned to the user program to clear out the receive buffer so that HFC can be released and bytes can be transmitted. When HFC is released by a "read" system call, the SL driver will transmit all buffered transmit characters in a polling loop before returning. Currently, if the transmit buffer overflows, the overflow characters are simply dropped. In the future, the "write" call will return with an error with information about how many characters were successfully buffered for future transmission, so that it can recover on its own.

5.7. SMART-WATCH DEVICE

The "config" program will attempt to read the current time from the SmartWatch device you have plugged into port #1 if you set a "time-device" field in the system configuration to the special value of 254. The code was donated by Randy Weems (rweems@edge.ercnet.com) and has been integrated into the configuration program. Randy says:

If you're wondering what a SmartWatch is...it's a cool little pass-through socket originally designed for PCs I think (and Apples) that gives you a battery backed clock in a transparent manner. You remove a ROM, plug the SmartWatch into the ROM's socket and plug the ROM into the SmartWatch socket. If you have a driver that reads from the ROM in just the right sequence, the SmartWatch kicks in and sends the date/time one bit at a time. Of course, there's always the possibility that the ROM could accidentally be read in the sequence that triggers the SmartWatch, but it's extremely unlikely.

Anyway, I never could get it to work "properly" on my 128D (by plugging it into a ROM's socket), but I found plans for hooking it up to joystick port 1 and drivers for GEOS. It doesn't interfere with the joystick port or keyboard at all.


6. COMMANDS

The following subsections give the low down on all of the executable programs provided with ACE, including the system programs and external user programs. For each command, a synopsis is given, followed by the description.

6.1. BUILT-IN COMMANDS

These commands are built right into the command shell.


echo [arg ...]

Print the given arguments to stdout, with a space between each and a carriage return at the end of the line.


clear
cls

Clear the screen. "cls" is the MS-DOS name and "clear" is the Unix name. This command simply emits a "form-feed" character to stdout.


ls   [-help] [-l] [-c] [-f] [dirname ...]
dir  [-help] [-l] [-c] [-f] [dirname ...]
d    [-help] [-l] [-c] [-f] [dirname ...]
clsl [-help] [-l] [-c] [-f] [dirname ...]

Display a directory listing of the given directory or of the current directory if no "dirname" is given. This command has so many variants because it is so useful. "dir" clears the screen before giving a long-form directory listing. "d" gives a long-form directory listing without clearing the screen. "ls" gives a short-form directory listing without clearing the screen, and "clsl" gives a short-form listing after clearing the screen.

Short-form listings include only the filenames of the files in the directory, whereas long-form listings include directory name, file permissions, date and time of last modification, length (in blocks*254 bytes), file type, and filename. On 40-col displays, the date and time fields are omitted.

The "-help" flag will make the command prints its usage information, "-l" will request a long-form listing, "-c" will request that the screen be cleared first before showing the listing, and the "-f" flag will request that the number of files and the total size in bytes of all the files be displayed in addition to the number of bytes free on the device for a long-form listing (note that only files are included in the count and bytes data; directories are not).


cd [dirname]

Change the current working device and directory to the given directory name. If no directory name is given, change to the "home" (initial) directory.


cat [file ...]

Display the contents of the named files to stdout. If no files are named, then input is taken from stdin (normally the keyboard).


exit
x

Exit from the command shell. EOF on stdin (normally Control-D from the keyboard) has the same effect. If the current command shell is the initial one started by the system (process #2), then ACE will exit back to BASIC. Otherwise, the command shell will exit back to the program that invoked it.


dos command
@   command

Give a Commodore-DOS command to the current device (OPEN1,dv,15..). Both "dos" and "@" are exactly synonymous.


path
path dirname ...

Display or set the path to search for searching for external programs. "path" alone on a command line displays the current search path, and "path" followed by arguments will set the search path to the following arguments.


sh [-vi] [scriptname]

Invoke a sub-shell. Currently, this is actually an external-command call. If the "-v" flag (version/verbose) is used, then the version "banner" is printed when the shell starts, and "-i" (initialize) will cause the new shell to execute the ".ashrc" shell script before accepting commands from its regular input file.

If the "scriptname" argument is supplied, then input is taken from the named file; otherwise, input commands are taken from stdin.


6.2. SYSTEM PROGRAMS


ace

This is the main loader. It determines whether it is running on a 128 or a 64 and then loads and runs either "ace128" or "ace64" below.


ace128
ace64

These are the kernel programs.


config

The system configuration program. This is not a user-executable program; it is loaded and executed while the system is bootstrapping. This program loads the ".acerc", "ace-charset", and "ace-charset-4bit" files, initializes the dynamically allocated memory, and sets the date.


config.edit

The configuration editor written in BASIC. LOAD and RUN it directly from BASIC. Full-screen interface. Same program runs on either a 128 or 64.


6.3. EXTERNAL PROGRAMS


cp [-f] file destfile
cp [-f] file ... directory

A file copier. Operates like the Unix file-copier program. If you give two filenames, will copy the first file to the second name. If a number of file names are given and the last argument is a directory name is given, will copy all of the files, retaining their names, into the given directory.

If a file that you want to copy to already exists, then you will be prompted for whether you want to overwrite the file: yes, no, all, or quit. Answering Yes will overwrite the file, and continue onto the next file. Answering No will abort copying the current file and continue onto the next file. Answering All will have the same action as Yes, except that it will never ask your permission again; it will always assume Yes. Answering Quit will abort the entire copy operation without disturbing any more files.

If, on the other hand, you use the "-f" option (force), then the command will overwrite existing files without pestering you for permission. Or, if the stdin file stream is not connected to the console, then the "force" option will be presumed. I would really like to get a "-r" (recursive) option working. Maybe in an "xcp" variant.


rm file ...

File remover (scratcher). All named files will be deleted.


mv oldfile1 newfile1 ... oldfileN newfileN

File renamer. For each pair of names, the old name will be changed to the new name. If the new name already exists, then the program will report an error. This uses the crufty Commodore rename DOS command, so don't even think about renaming a file that is not in the current directory or "moving" a file between directories.


mkdir flatDirName

Create a new subdirectory in the current directory. The given name must be "flat", i.e., it is just the name like "dirname", without any "/"s or ":"s.


rmdir flatDirName

Remove an existing empty subdirectory in the current directory.


wc file ...

Word counter. Counts the lines, words, and characters in a file. To count lines, the program simply counts carriage returns (code 13 decimal). A word is any non-whitespace character(s) between whitespace characters. Whitespace is defined as the characters SPACE, TAB, and RETURN (codes 32, 9, and 13 decimal, respectively). If multiple files are specified, totals will be reported.


grep [-[i][v]] [^]substr[$] file ...

The "i" and "v" flags are optional. "i" means to ignore the case of letters in comparisons and the "v" means to invert the search - display lines that do not match the pattern.

The substring may begin with "^" which means only to check for the string at the beginning of a line, and may end with "$" which means only to check for the string at the end of a line. Both "^" and "$" may be used at the same time. There is no escape character, so you'll have problems trying to seach for the two anchor characters in the files.

One or more files may be specified to be searched. If more than one file, then the name of the file will preceed each line printed that matches. Output goes to stdout. Some examples follow:

grep hello hello_world.c
grep -v '^$' file1 >file1.noblank
grep -i crAiG Hack*
grep -iv 'the$' file2

The first example simply searches for the string "hello". The second example removes all blank lines from the input file. The third example searches the Hack1, Hack2, Hack3, Hack4, and Hack5 files (for example) for the word "craig" which can be in any case (eg. "Craig" would match). The fourth example displays all lines that do not end with the word "the" in any case (eg. the second line of this paragraph would be omitted).

Some limitations of the program are: only the first 2048 characters of a (really long) line will be considered, lines may not contain the character code $00, and the last line of the file must end with a RETURN (or it will be ignored).


tr [-i] [-fromset2toset] file ...

Translate files from one character set to another. Character sets supported are: Petscii, Ascii-CrLf (MS-DOS), Ascii-Lf (Unix), Ascii-Cr, and SpeedScript. "fromset" and "toset" in the synopsis above may be any of: "p" (Petscii), "a" (Ascii-CrLf), "al" (Ascii-Lf), "ac" (Ascii-Cr), "s" (SpeedScript), "c" (Commodore == Petscii), "u" (Unix == Ascii-Lf), or "m" (MS-DOS == Ascii-CrLf).

The the character set specifiers are separated by the character "2" (meaning "translate to"). If the translation specification argument is missing, the default of translating from Ascii-CrLf to Petscii is used. Input is taken from the files and all output goes to stdout in order.

Example:

tr -s2u file1 >file1.unix

Translate from SpeedScript format to Ascii-Lf (Unix) format the contents of "file1" and put into file "file1.unix".

The name "tr" is used (a Unix utility) because the functionality of this program will grow to include that of the Unix "tr" utilitiy.

The "-i" option means to do an "in-place" translation. I.e., the original file will be overwritten with the translated data. To achieve this, a temporary file is created in the temporary directory that is the size of the final file, and then removed. Make sure that your temporary directory will have enough space to do the translations.


sort [-[i][v]] [+column] file ...

Sort utility. Currently uses a sucked-out insertion sort algorithm. Will be extended to use the "Approximation Sort" algorithm, which has between O(N) and O(N^2) performance (close to O(N) for random data). Makes use of dynamically allocated memory to store large files internally.

The "i" and "v" flags are optional. "i" means to ignore case of letter characters in comparisons to determine order. The "v" flag means to inverse the order of sorting (put into descending order rather then the usual ascending order). The +col field is optional, and if present, gives the character position of the start of the sorting key. The default starting position is 1 (the beginning of the line). A TAB character will be interpreted as any other character.

If multiple files are specified, they will all be merged together and then sorted as a group. Sorted output goes to stdout. If the program dies in the middle of its operation (eg. out of memory), all files owned by the program (process) will be closed and all memory allocated to the program will be reclaimed. This is also true for all other external programs, since this is implemented in the kernel.


wrap file ...

This is like the cat command, except that lines longer than 75 characters will be word-wrapped into multiple lines.


date

Display the current date. The format is: "YYYY/MM/DD-HH:MM:SS.T", in 24-hour time format. This command will be extended to display in "human mode" (eg. "Tue-13-Jul-1993 05:49:53 pm") and to allow you to set the date. Currently, the date will only be set when the system starts up.


forty

Switch to the 40-column (VIC) screen on the 128. This also switches the processor into slow mode.


eighty [rows]

Switch to the 80-column (VDC) screen on the 128 or to the soft-80 screen on the C64. On the C128, this will also switch the processor into Fast mode and will set the VDC screen to display the number of rows that you request, or the default number of rows (config option) if you don't specify a number of rows.


read file ...

File reader. Useful only for testing how long it takes to read a file. No output is generated.


mem
mem address

Display bytes of dynamically allocated memory that are still free and the process id of the "mem" process. If you give the "address" option (a 32-bit hexadecimal address), then the memory contents from the given address (aligned on a 16-byte boundary) for 256 bytes are displayed in an 80-column format. Users won't normally use this option; it is intended for debugging.


hello

This is just a dippy little program that prints out a "hello world" message. It is included so programmers may examine it and its source file to see how simple ACE programs are organized.


window [columns [rows [startColumn [startRow]]]]

Sets the window size. If no arguments are give, it will report the current window dimensions. If one or more arguments are given, they will be used as window arguments as above. Missing arguments will be taken from the current window's settings. Screen coordinates start at column 0 of row 0 and go to the full size of the screen. You will get an error message if you try to set up an illegally sized window and the current window will remain unchanged. After successfully setting a window, it will be filled with a checkerboard pattern to indicate the size of the window. Just clear the screen to get rid of this.


chrset file

Loads the named file for use as the current character set. The file must be a valid ACE character set.


keymat file

Loads the named file for use as the current keyboard translation matrix.


head [-N] [file ...]

This utility was donated by Jake Hamby. He says: It prints the top N lines of any file (or STDIN if no file is given), where N defaults to 10. It detects the RUN/STOP key, and prints a usage message if given bogus arguments.


jif

Displays the current jiffy-clock time to standard out. ACE's jiffy clock is a 32-bit quantity.


mousetest [-h [-t]]

This allows you to move crosshairs around on the hi-res screen with a mouse plugged into port #1. If one argument is present, then the regular hi-res screen is used (usually, the lowest-resolution screen is used), and if two arguments are present, the program will perform a graphics speed test (you'd have to examine the code to see what is being tested).


more file ...

Full-screen file viewer. At the prompt, press SPACE to view the next screenful of a file, RETURN or cursor-DOWN to view the next line, N to go onto the next file to be viewed, or STOP or Q to exit the viewer. Future expansion possibilities include a "go back" command and an ASCII-translation mode.


uuencode [-a] [-al] [-u] [-ac] file ...  >outfile

A uuencoder. The uuencode program sends its output to stdout, so you will usually want to redirect stdout to a disk file. This output will be in Petscii characters by default, to work with the other text utilities. If you wish to have the output in Ascii, then you can supply one of the flags shown in the command template. "-a" means to produce ASCII-CrLf output, "-al" and "-u" (Unix) mean to produce ASCII-Lf output, and "-ac" means to produce ASCII-Cr output. You will very likely want to redirect the output to another file with ">outfile" (substitute the name).


uudecode file ...

A uudecoder. The uudecode program will accept either Petscii or Ascii files and is able to extract multiple files from one input file. Extracted files are put into PRG files.


bcode [-help] [-v] [-u] [-m] [-l max_line_count] [filename ...]

See the external documentation for this application.


unbcode [-help] [-i] [-v] [-d] [filename ...]

See the external documentation for this application.


crc32 file ...

CRC32 generator. The numbers generated by this program match CRC32 value generated by other programs, such as PKZIP and ZMODEM. This program is used to verify that files have been transported from place to place correctly.

The program uses a table-driven byte-oriented algorithm, so it executes very efficiently.


unkar file ...

KAR (Kevin's ARchiver) dearchiver, intended to be used for extracting the ACE source code, although you may find this archiver format useful for your own purposes.


kar [-help] file ...

KAR archiver. This may be used to encode any text files into a single KAR archive. Only text files may be archived, and the resulting archive is also a text file, so you can look at it, mail it, etc. All of the named files are included and output goes to stdout, which you will likely want to redirect.


vbm [-help] file ...

This is a ported version of a program (VBM Bitmap Viewer version 1.10) that was released earlier as a stand-alone program. The ported version has all the benefits of all ACE programs: it will run on either the 128 or 64 and you can conveniently specify the files you want to use the program with. You will want to get the image files and the C-language xbm-to-vbm converter that were bundled with the original program.

This program required some kernel improvements, including adding basic support for 320*200 monochrome graphics on the 64 and 640*200 and 640*491 (NTSC-64K only) using the VDC display of the 128. Note that the 320*200 and 640*491 displays have a pixel aspect of 1-to-1 and the 640*200 display has a pixel aspect ratio of 2-to-1. Since images are normally encoded with a 1-to-1 aspect ratio, images will look twice as tall as they should on the 640*200 display. The vbm program doesn't attempt to correct the aspect of images (yet).

When you start the "vbm" program with image files specified, it will display the image and then wait for you to press a key. Pressing "Q" will exit from the program. Pressing any of the cursor keys will scroll the image a quarter-screen in the direction you press. Pressing the HOME key will return you to the "home" position of the image. Pressing the SPACE BAR or RETURN key will cause the next image in the "slide show" to be viewed. After the last image, the viewer will exit. Oh, while displaying the current image, the program will "peek" at the keyboard buffer and if you have typed any key, it will stop displaying the image and interpret the key. This will allow you to position or select an image quickly. There are other positioning commands summarized as follows:

UP,DOWN,LEFT,RIGHT: 1/4 page scroll
SH-RIGHT,SH-LEFT  : 1/2 page scroll left/right
SH-LINEFEED,LF    : 1/2 page scroll up/down
CT-LEFT,CT-RIGHT  : full page scroll left/right
CT-UP,CT-DOWN     : full page scroll up/down
i,m,j,k: small scroll up,down,left,right
1 to 9 : set small-scroll jump (times 8, in pixels)
CO-LEFT,CO-RIGHT  : go to end left/right
CO-UP,CO-DOWN     : go to end up/down
HOME   : go to top left of image
CLR    : go to center of image
HELP   : display this help information
(basic keyboard has equivalent cursor-movement keys)

Pressing "?" or HELP will bring up a screen with help information and the name and number of the file being viewed. Pressing "0" will take you to the first image given on the command line, and pressing "$" will take you to the last image on the command line.

The VBM custom image format is basically a binary representation of the XBM format for X-windows bitmaps, where XBM gives its data in C-code format. There is now a newer version of the VBM format (version #3; the older one was version #2), and it features RLE data compression, which gives about 29% smaller files on average than version #2 did. The viewer program can accept either version #2 or version #3 images.

The "pbmtovbm.c" file in the "aceNN-usrc.kar" archive C program that will convert a file from XBM format to VBM format. So, all you need to view any arbitrary GIF or JPEG file on your 128 is a program like Unix's "xv" to convert the image into ".xbm" format, and then convert that into ".bm" format. The ACE viewer will let you scroll around in images larger than 640x491 (et al), so you don't have to cut the size of larger images. The maximum image size that "vbm" will handle is 2040x65535.


vbmpr [-help] file

This program only accepts version #2 images; I will eventually integrate this into the VBM viewer program above.

The indicated file will be printed, and if there are multiple files, they will be printed one directly after the other. All images are printed from the left margin, and the program uses the 640 dots-per-line graphic mode of the printer. This will produce an image that does not have a perfect aspect ratio (which would be 576 dpl), but I figured that it would be more important to be able to print 640xN images. The height of an image is, of course, limited only by the amount of paper that you have.

When run, the program will open a channel to your printer through device "q:" of your configuration. This device should be set up as a transparent-mode non-auto-linefeed connection to your printer/printer interface.

I tested the speed of the program on a 640x480 image, and it took ten seconds to input the image from the ramdisk and output the printer data to the null device, so the bottleneck in the system for printing images will definitely be the speed of the connection to your printer or your printer itself, and not this printing program.


as [-help] [-s] [-d] [file ...]

See the external documentation for this application.


term

See the external documentation for this application.


fx [-78k] [[-b] file ...] [-t file ...]

See the external documentation for this application.


z file

See the external documentation for this application.


7. LATER, DUDE

This system is Public Domain Software.

If you have questions, comments, suggestions, or bug reports, you can contact me at the following e-mail address.

Keep on Hackin'!

-Craig Bruce
csbruce@pobox.com
"Everything from ACE to ZED!"


The Official ACE Page is at: http://www.pobox.com/~csbruce/cbm/ace/.
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