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Alpha Micro AM-100/L and related boards

retrobits

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May 22, 2007
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Portland, Oregon, USA
Hi everybody,

As part of a retro rescue a few months back, I received a couple of S-100 chassis systems. One contained only the backplane and power supply. The other was loaded with Alpha Micro and related boards. There appear to be two AM-100/L 68000-based CPU boards, floppy controller, SCSI controllers, a serial multiplexer, and a couple of other boards.

Unfortunately, the drive subsystem and OS had been scrapped some time ago, so this is not a working system. Even if I had the dual 8" floppy unit, I wouldn't have anything to boot it with.

Both of the S-100 boxes are extra tall - I think this was a requirement for some of the Alpha Micro boards.

I haven't really decided what to do with this. It would be challenging to bring it back to life. I've looked for info online - there were some Alpha Micro info resources out there, but they appear to be offline. I couldn't find manuals, etc. for the AM-100/L system. I do have a couple of manuals in good shape that came with it - perhaps if those aren't out there, I can get them scanned and available.

Comments? Interest in pictures/scans/etc.? Ideas on ways to make it live?

Thanks,

- Earl
 

Chuck(G)

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Jan 11, 2007
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I thought that the AM-100 was pretty cool--used the WD16 chipset; basically the DEC LSI-11 set but with different microprogramming. The AM-100/L less so; just another 68K-based CPU board. IIRC, the floppy controller in either system is a WD1771-based one; i.e. single-density (FM), so nothing special. There probably were later versions of the controller that accommodated double-density. You could probably rig something up with modern 3½" legacy drives without too much problem.

The bigger issue is the AMOS/L OS used with the system. Perhaps Alpha Microsystems might be able to help. They keep a lot of old documentation around, though the AM-200 floppy controller info is on Marcus Bennett's site.
 

Al Kossow

Documentation Wizard
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Silicon Valley
I couldn't find manuals, etc. for the AM-100/L system. I do have a couple of manuals in good shape that came with it - perhaps if those aren't out there, I can get them scanned and available.

Comments? Interest in pictures/scans/etc.?

If someone has an AM-100L, I could use boot prom images. One of them is bad on a machine I have.

It is a weird configuration, though. It has an Inner Access SCSI board, so the prom is probably custom.

scsi.jpg
 

Terry Kennedy

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Jul 7, 2017
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New York
I thought that the AM-100 was pretty cool--used the WD16 chipset; basically the DEC LSI-11 set but with different microprogramming.
Yup - there were at least 4 versions of the WD-16 - the LSI-11, the Alpha Micro, the Pascal Microengine and something I don't know the name of that was used in AT&T/WeCo high-end modem/muxes. Interestingly, the WD-16 is actually an 8-bit processor pretending to be 16-bit.

But - don't get me started on Alpha Micro's bastardized over-size boards, which got shoved into IEEE 696 (as "Compliance H") over the strong objections of many of us.

The AM-100/L less so; just another 68K-based CPU board. IIRC, the floppy controller in either system is a WD1771-based one; i.e. single-density (FM), so nothing special. There probably were later versions of the controller that accommodated double-density. You could probably rig something up with modern 3½" legacy drives without too much problem.

The bigger issue is the AMOS/L OS used with the system. Perhaps Alpha Microsystems might be able to help. They keep a lot of old documentation around, though the AM-200 floppy controller info is on Marcus Bennett's site.
All of the Alpha Micro systems I worked on had CDC 9448 (AKA "Phoenix") drives. Stan Veit of Computer Mart of New York was one of the early Alpha Micro distributors, under the Dravac division. I was involved in field service for some of his systems - sometimes I'd get a request to fly to Morocco to fix a system they'd sold to the government airline (Royal Air Maroc).

Tying this all together, some years later Stan and his business partner Dave Levine started Veit's Diversified Operating Systems (also in NYC) which was the east coast rep for the WD-16-based Pascal Microengine.
 

Al Kossow

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The bigger issue is the AMOS/L OS used with the system.

This is what got me started down this rathole.
I've been going through hundreds of cartridge tapes, and I found and recovered about two dozen of them circa 1984/5 for Alpha Micro
including AMOS/L install tapes. I was hoping to find AMOS, but it wasn't there.
I also recovered install tapes for AMIX/UNIMOS, their version of Unisoft System V.0 that only ever shipped on the AM-1100

This is also why I'm looking for info on the AM-620 cartridge tape controller. I suspect they were not widely used, and the boot proms.
We have an AM-1142, but the old 8" drive was replaced with a SCSI controller (no drive came with it) and a VCR tape backup, but one
of the two boot proms is dead.

I see an AM-100L sold on eBay in January
I wonder who got it

https://www.ebay.com/itm/254052141343
100L.jpg
 

Al Kossow

Documentation Wizard
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I sold it. I looked for am-620. if I find one I'll let ya know

thanks!

I just recovered about two dozen factory cartridges ca. 1984
so there is some chance I can put the system back together.
if I can find the right boot proms.

19022310.jpg

Could you PM me if you have any AM-100 installation media?

The next project is trying to digitize and decode some VCR backups.
 

syloldcmp

New Member
Joined
Aug 21, 2018
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Location
Winnipeg
I acquired an AM-624 (dated 1986) external self-powered (9 Volt adaptor) board which appears to be a combination SCSI interface and a VCR controller. It has the remote VCR self-control adapter as part of the board as well as the two standard video in and out connectors. There is a SCSI cable connector to fit into the external SCSI port on the back of the Alpha computers. The board has three removable jumpers and an 8 position dip switch. My biggest problem is that I have no documentation and that is making interface to the Alpha Eagle 300 difficult. Can anyone help me with any information about this board. Thanks.
 

curbie

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Joined
Mar 23, 2019
Messages
103
If someone has an AM-100L, I could use boot prom images. One of them is bad on a machine I have.

It is a weird configuration, though. It has an Inner Access SCSI board, so the prom is probably custom.
you still looking? still have the source code.

1984/5 for Alpha Micro including AMOS/L install tapes.
were any of AMOS/L tapes for version 1.0 or 1.1a?
 

curbie

Experienced Member
Joined
Mar 23, 2019
Messages
103
well, i wrote boot prom code and still have the source code for AM100/L using an IAC card when the project gets to the top of the stack.

were any of AMOS/L tapes for version 1.0 or 1.1a?
 
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