Micro-minis? Whatever happened to them?

[glitch]

Alright, I dug out the OS-65U manuals! In the introduction:

OS-65U includes a timesharing executive program that provides file load, save and print functions to up to 16 intelligent terminals (C2-4P's and C2-8P's). This distributed processing allows each of the 16 users to access floppy disk or hard disk sotrage for their BASIC programs and to share a central printer for hard copy listings.

Sounds like the end terminals might be doing a little more work than I previously assumed!

I've nearly got the CP/M escort disk working with the system...I've got 48K of static RAM in regular OSI 420 boards. I need the additional 8K starting at $D000, but have been unable to set one of the 420 boards for this RAM address -- I believe, looking from the schematic, that the board sends a "board active" signal, so even though I've got one of them strapped for $C000 and the first and last RAM banks pulled, the board still asserts itself over the system ROMs up at $F000, meaning the machine won't boot.

I do have, IIRC, a OSI 525 card, which is a dual-port RAM card usually used with hard disk controllers (its original purpose in this system) or high-end graphics. It will accomodate several banks of 4K through 2114 static RAMs...it's currently populated with only 4K, at I believe $E000. I can't find a schematic for it, so I can't determine how I should add another 4K to it, as that would be optimal. I do actually have a large quantity of the Molex "Jaguar" connectors that OSI used for the system bus connectors, so I could build a RAM card, but I'd probably have to use smaller RAMs to better accomodate the bus layout. I was considering using a quantity of 6116 static RAMs and a 4-of-16 decoder/demultiplexer, but I haven't had too much time to actually work with the OSI lately.

It /will/ eventually boot CP/M, as I know it has in the past (there are DIR listings from CP/M in the ring-bound manuals my boss gave me)!

 

[MikeS]

ISTR that someone wrote a CP/M for the 6502 in an OSI, although I don't know what you'd actually run with it; anybody know or remember that?

Edit: Found it; it was called DOS/65 and ran on the C1P and C4P, as well as the AIM-65 and KIM etc.
Anybody ever try it?

 

[retrohimpi]

Alright, I dug out the OS-65U manuals! In the introduction:



Sounds like the end terminals might be doing a little more work than I previously assumed!

That seems a lot more reasonable - not much more than a glorified file/print server for a bunch of desktop micros

I've nearly got the CP/M escort disk working with the system...I've got 48K of static RAM in regular OSI 420 boards. I need the additional 8K starting at $D000, but have been unable to set one of the 420 boards for this RAM address -- I believe, looking from the schematic, that the board sends a "board active" signal, so even though I've got one of them strapped for $C000 and the first and last RAM banks pulled, the board still asserts itself over the system ROMs up at $F000, meaning the machine won't boot.

Could you strap it for $B000 and fill it completely, stealing RAM chips from the top banks of the existing board at that address, so that it doesn't overlap the system ROMs or I/O ports?

I do have, IIRC, a OSI 525 card, which is a dual-port RAM card usually used with hard disk controllers (its original purpose in this system) or high-end graphics. It will accomodate several banks of 4K through 2114 static RAMs...it's currently populated with only 4K, at I believe $E000. I can't find a schematic for it, so I can't determine how I should add another 4K to it, as that would be optimal. I do actually have a large quantity of the Molex "Jaguar" connectors that OSI used for the system bus connectors, so I could build a RAM card, but I'd probably have to use smaller RAMs to better accomodate the bus layout. I was considering using a quantity of 6116 static RAMs and a 4-of-16 decoder/demultiplexer, but I haven't had too much time to actually work with the OSI lately.

It /will/ eventually boot CP/M, as I know it has in the past (there are DIR listings from CP/M in the ring-bound manuals my boss gave me)!

Hope you can workaround the problems and make it boot. Do you have any interesting CP/M software to run once you get it going? I presume that the Challenger's non-standard disk format means that you won't be able to use regular CP/M disks.

 

[retrohimpi]

ISTR that someone wrote a CP/M for the 6502 in an OSI, although I don't know what you'd actually run with it; anybody know or remember that?

Edit: Found it; it was called DOS/65 and ran on the C1P and C4P, as well as the AIM-65 and KIM etc.
Anybody ever try it?

I'm hoping to try it on my C1P emulator, once I get the bugs out and the virtual drives working correctly. DOS/65 comes with a BASIC compiler and a 6502 assembler, so I'll be writing my own software to run on it.

 

[MikeS]

I was considering using a quantity of 6116 static RAMs and a 4-of-16 decoder/demultiplexer, but I haven't had too much time to actually work with the OSI lately.

If you're even slightly serious, let me know how many 6116s you want and I'll throw 'em in with the Cromemco boards; I've got lots of 'em.

 

[MikeS]

I'm hoping to try it on my C1P emulator, once I get the bugs out and the virtual drives working correctly. DOS/65 comes with a BASIC compiler and a 6502 assembler, so I'll be writing my own software to run on it.

The developer, Richard Leary, is still around AFAIK; he posted a few times on the comp.os.cpm list and seemed to be pretty approachable.

 

[saundby]

There were some NS 16032 and 32032 systems out there, but the prices were way up there and the market was going 68000 while rumors of 286 and 386 Unix abounded. I used the NS chips in some embedded work, so I would have liked to get a workstation based on them to make programming that much simpler. But when I saw the prices for even a basic 16032 system I sucked in my breath and decided cross-compilation isn't so bad after all.