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MAI Basic Four BB1 64K FERRITE CORE MEMORY BOARDS

E

evanderryd

New Member
Joined
Sep 8, 2020
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Location
Southern Ontario, Canada
Hello,

As a former employee of MAI / Basic Four Computers in Canada, I have a few vintage parts laying about.
Manufactured in California by Standard Memories / Applied Magnetics Trendata
Model R32K18MM
Last tested in 1986 in anti-static bags.

I am curious to know if anyone might be interested in these items.
 
evanderryd said:
As a former employee of MAI / Basic Four Computers in Canada, I have a few vintage parts laying about.
Manufactured in California by Standard Memories / Applied Magnetics Trendata
Model R32K18MM
Last tested in 1986 in anti-static bags.
Click to expand...
While I have no need for them, I believe the original Microdata Basic Four system (clock-reset-run) and the instruction-compatible in-house implementation used different memory. And then there was the "new architecture" generation (or generations, but I was out of contact by then). So clarifiying which system(s) these work in would probably be helpful.
 
@m_thompson
Do you have plans to get the 1200 up and running again ?
For the 1200 (that is in fact a microdata 1600), i have
1) 8 K Core memory board, Microdata assy A20002208 REV G, Date 03/1976
2) 8 K Core memory board, Microdata assy A20002208 REV C, Date 02/1974
3) SORBUS ROMBUG rom board used by SORBUS service for diagnostics
3) Font pannel board (the large one with switches)
mem1.jpgmem2.jpgrombug.jpgpannel1.jpgpannel2.jpg
 
I have recreated the documentation for the 1200 ROMBUG and sent it to Al for uploading to bitsavers. This was a challenge, when i got them, they where wet, moldy and barley readable.
http://basicfour.de/download/1200/Rombug_BasicFour_1200.pdf

I got another manual that may be helpful as it contains assembler documentation as well as small test programs for the 1200 and 13xx CPU's (also sent to Al):
http://basicfour.de/download/13xx/S-HDBK-211_SORBUS_SR_HANDBOOK_FOR_BASIC_FOUR_1981.pdf

If you really plan to get one of the machines up and running again, i could donate the boards that are useful for you. (I only have 13xx CPU's and no 1200 ones)

Btw, what is the preferred way of sending documents / software to be uploaded to bitsavers. I got a lot of software from a former MAI employee in the Netherlands for the Basic Four S/10 including discs for creating the copy protected operating system disks that i would like to preserve ?
 
I have an MAI Basic Four, but I know little about it. Maybe somebody here can offer some pointers? The stickers on the back of the enclosure give a model number of 4108 and 4008. It has apparently been "upgraded" at some point. The enclosure is about the size of a desktop PC, and it is VERY heavy. It has a Maxtor XT-1085 hard drive (I think that's about 80 MB?), and a cartridge tape unit. It is 68010 based (I'm guessing 8 MHz?). I do know that it was capable of supporting a number of terminals, and was used by a lobbying firm in Washington, D.C., as their office system before being replaced with a PC network (many years ago). I think it has over a MB of DRAM memory, and the hard drive still spun up the last time I turned it on, although it sounds like a 747 taking off! The O.S. is some sort of UNIX, but there are no utilities present (that I can find) to poke around in memory or dump the hard drive. I think I remember seeing "BOSSIX" when I had it running last? I'd love to get the contents of the hard drive saved on some sort of SD device; maybe revive the system on more modern hardware? I used to have the capability of running 506 MFM drives on a PC, but I haven't done that in years. Any hope of getting anything saved from this beast?

Roger
 
Replying to my own post. The main board (at the bottom of the case) is very large (roughly 20" x 13"), and it looks like the power supply is attached directly to it. It sits right on top of the PCB, and I did not attempt to disassemble that part of the computer. There is a 2764 EPROM right next to the 68010 CPU on the main board. So, I dumped it. The first 8 bytes make sense to me -- looks like an initial SSP, and PC. BUT, the rest of the ROM appears to be garbled. Character data at the end of the ROM doesn't make sense either. Also, I would expect some 4E75 sequences in code like this (RTS instruction), but there are none. Three smaller cards sit on top of the main board (at one end of the case). One is a SCSI controller (runs the cartridge tape drive) that uses a Z80. Its ROM is also a 2764, and the contents make sense for Z80 code. On top of that is a 4-way serial comm. board, again controlled by a Z80, and its ROM looks like valid Z80 code. The last card is a WDC controller for the hard drive. It has an 8085 on-board, and the contents of its ROM also looks good (although I don't know a lot about 8085 assembler). What I'm seeing looks quite similar to Z80 code, which is what I'd expect.

Is it possible that MAI used some sort of a proprietary code scrambling technique to obfuscate their code, and discourage snoopers such as myself? I don't understand the contents of the 68010 EPROM, but I don't think it is suffering "bit rot" (the computer runs, or did the last time I powered it on).

Roger
 
Looks like a system 2000
some infos here: http://basicfour.de/
It runs BOSS/IX that MAI Basic Four has licensed from Charles River Data Systems where it was named µNOS.
The WDC is based on an Adaptec SCSI to MFM adapter, early versions of the 2000 had the original Adaptec installed, later they integrated that design into their own board. The firmware contains adaptec as well.
I have dumped the eproms of my machine as well: http://basicfour.de/download/mai2000/
Is it possible that MAI used some sort of a proprietary code scrambling technique to obfuscate their code,
Click to expand...
at least not in the eproms. I have started to write an emulator for the System 2000, it is far from complete but it runs the code that is in the eprom on the main board and can boot the diagnostics from emulated tape.
One is a SCSI controller (runs the cartridge tape drive)
Click to expand...
In fact that is a QIC (02 ?) controller
'd love to get the contents of the hard drive saved on some sort of SD device
Click to expand...
The easiest way would be to backup to tape and than read that back on a linux system. You can make 2 different backups
1) via the diag tape using dutil, that is a sector copy of the hdd to tape. For that you have to boot from tape.
2) via tsave running on boss/ix, i have created a small program that can at least extract the files without timestamps from these backups

Do you have the BOSS/IX tape ? (Btw, do not try to read that tape, the belt has become loose and you will ruin the tapes without changing the belt)

Btw, i have uploaded a lot of documentation for the 2000 to bitsavers: http://bitsavers.informatik.uni-stuttgart.de/pdf/mai/

If you need help, you can contact me directly, email on pages linked above.
 
Hello there can you help me by telling me which is that model exactly for the name and also year ?
And if it is worth something or not ?
Thanks a lot for help
 

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