Ohio Scientific Superboard II Rev B mod question

[royedmund]

Can anyone tell me what this mod and ROM

rom.jpg (94.62 KiB) Viewed 2745 times

does? Superboard II Model 600 Rev B''

proto1.jpg (121.38 KiB) Viewed 2745 times

proto2.jpg (100.49 KiB) Viewed 2745 times

[harrywalter99]

I am not an expert on the subject but there is a reference to Dabug under software on the osiweb. ref: https://osiweb.org/software.html

It looks like you have an interesting project there!

[Mark]

I found an ad for DABUG III here https://worldradiohistory.com/hd2/IDX-A ... e-0149.pdf
Which claims it to be an on screen editor etc. so I installed the DABUG ROM image in WINOSI to see what it does.

It includes the following text embedded in the ROM "DAVID ANEAR 2/2/81"
Many parts of it are unchanged from a standard OSI SYN600 system ROM, it has the same keyboard poller, floppy disk loader, and nearly unchanged 65V monitor, but it includes some hooks that took me a while to figure out.

One thing it does is patch the keyboard input location to look for CTRL + Left-Shift key presses. When found, it loops continuously, effectively pausing execution of BASIC programs. In other words you can freeze a BASIC program by holding CTRL+LShift

Eventually I discovered the DABUG editor hooks itself into BASIC-IN-ROM when you press CTRL+Q. At this point it shows a double "^" character on the bottom row of the screen indicating it has been activated. (I don't think it's available for disk based systems since they don't use ROM based routines).

Once DABUG is active, the following commands are available:
CTRL+U Start screen editor mode and move cursor up one line
CTRL+D Move cursor down
CTRL+> Move cursor right
CTRL+< Move cursor left
CTRL+A Copy character at cursor to input line buffer (& bottom row of screen) and move right
CTRL+B Toggle 48x16 mode on OSI600D (& patch screen printer)
RUB-OUT backspace/full screen clear
SHIFT+O true backspace

There may be more features left to uncover!

Attached is an example of it activating and using it to edit a line of BASIC. Afterwards I pressed CTRL+LeftShift to pause before terminating the program.

DABUG in action

screen0001.gif (50.99 KiB) Viewed 2720 times

Also attached is a partially annotated disassembly of the DABUG ROM.

(It reminded me that I wrote a similar BASIC screen editor for C2/C4 BASIC-IN-ROM machines back in 1981 which can be found on the cassette software page here: Unfortunately C2 machines don't have input vectors like C1P so the cursor is activated by generating a syntax error. )


Cheers,
-Mark

[Mark]

Well DABUG III had a couple more hidden features.

Turns out there is a BASIC keyword shortcut accelerator in this ROM too. Once DABUG has been activated, pressing ESC prompts you with a "=>" character. Typing almost any character enters a complete BASIC keyword. So pressing ESC then SPACE enters "PRINT" on the screen. The complete list follows.

Code: Select all

     A = ASC
     B = TAN
     C = SIN
     D = SGN
     E = RETURN
     F = FRE
     G = LEN
     H = VAL
     I = STR$
     J = STOP
     K = CONT
     L = LOAD
     M = LOG
     N = ATN
     O = DEF
     P = PEEK
     Q = NEXT
     R = RND
     S = SAVE
     T = RESTORE
     U = CHR$
     V = COS
     W = STEP
     X = LET 
     Y = READ
     Z = DIM
     0 = POKE
     1 = FOR
     2 = THEN
     3 = GOSUB
     4 = GOTO
     5 = INPUT
     6 = DATA
     7 = LEFT$
     8 = MID$
     9 = RIGHT$
     : = USR
     - = INT
   RUB = LIST
 RETURN = RUN
    LF = REM
 SPACE = PRINT
     > = NOT
     < = AND
     / = TAB(
     ; = END
     . = EXP
     , = SQR
     ? = SPC(
     + = CLEAR
   ESC = cancel keyword mode

I also discovered that when in 48x16 mode, the screen printer filters out the high bit, and refuses to print any non-ASCII character. So the BASIC syntax error message shows as ?SN ERROR without the graphics 'N' replacement.

Anyway I created an assembler listing with comments that assembles back to the same binary as the original ROM. I've added comments to the keyboard decoder and other areas throughout the monitor ROM. The attached ZIP file has the original ROM, the assembler listing and the keyboard shortcuts found exploring this code. It should probably replace the original zip file on OSIWEB.

[RedskullDC]

Hi Mark, Roy, et al.

That DABUG rom image up on osiweb came from a RevD Superboard II that came my way quite some years back.

From what I have been able to glean, "David Anear" was the hardware guy at the "Victorian 6502 Users Group" in the early 80's.

They had a regular newsletter called "KAOS, for those who got smart", which lasted at least until late 1983.
The group supported OSI, SYM, KIM, AIM, UK101, APPLE and ORANGE users.

The group also released a disk operating system called "COMP-DOS", though I haven't been able to find any info.

ROY: Be interested to see if your ROM has a different datestamp embedded?

Regards,
Leslie

[royedmund]

Thanks, everyone for the information. I have now tried the ROM on my recently repaired Superboard II. The images in the original post are from a Superboard II Rev B Model 600 which was recently donated to the Australian Computer Museum Society in Sydney. I'm only able to visit the ACMS every few months because of work and I also live 120km away in the Blue Mountains west of Sydney.

Now thanks to everyone's help the DABUG III ROM has been identified and now I'm interested in the mods to the video circuit with an additional TTL chip in the prototyping area which is connected to U70 7403 on the board but I might need to wait until I'm able to visit the museum again or I may have to ask for some better images of the mod on the board.



My simple demo of the DABUG III ROM https://youtu.be/CLP-CJ3yvyg

[BillO]

Do you have any idea what part number is on that added chip? We could then reverse engineer it to see what it might be up to.

[exidyboy]

The group also released a disk operating system called "COMP-DOS", though I haven't been able to find any info.

According to the directory listing created by Mark there is a copy of COMPDOS 1.3 on the rabble7 disk. It is one of the files that doesn't appear to have any errors.
Might be worth a look.

https://www.osiweb.org/osiforum/viewtop ... 4271#p4271

[exidyboy]

That DABUG rom image up on osiweb came from a RevD Superboard II that came my way quite some years back.

From what I have been able to glean, "David Anear" was the hardware guy at the "Victorian 6502 Users Group" in the early 80's.

They had a regular newsletter called "KAOS, for those who got smart", which lasted at least until late 1983.
The group supported OSI, SYM, KIM, AIM, UK101, APPLE and ORANGE users.

The group also released a disk operating system called "COMP-DOS", though I haven't been able to find any info.

The KAOS newsletters are not yet scanned in their entirety at preservation quality but I have had a quick look through the surviving issues that I have access to.

Attached is a compilation of rough scans of articles and news items relating to DABUG and COMP-DOS.

[Mark]

I was able to extract the Compdos 1.3 file from the Rabble7 disk along with its BEXEC* file.
In addition, I have made an assembler file for compdos which assembles back into a binary equivalent with A65.

Compdos is loaded off the Rabble7 disk track 15 with DISK!"CA B800=15,1/8 and is run from $B800 with DISK!"GO B800. It inserts itself into OS65DV3.3 when run, and expands the number of DOS commands available. This version requires a 48K OSI, but I believe the source is in a state that can be reassembled into other locations without too much difficulty.

It expects the 14 character filename modification to OS65D V3.3 / I wasn't able to locate that version right now.

It adds the following commands from what I can see:
DR - performs Directory
RN - performs Rename
DE - Delete ?
CR - Create ?
CO - loads track 0 read/write utility
BS
ZE - Zero ?
BR
SE
SP - Set Prompt

Not sure what they all do but you get the idea. The KAOS PDF file posted earlier has a few more details.
I've also included an OSI dump of the rabble7 disk for the Rabble65 computer where this compdos came from.
It loads but doesn't boot on OSI as it uses custom system ROM routines that have not been made available yet, but contains only a slightly modified OS65D3.3 for those interested.

Cheers,
-Mark