A childhood dream comes true: IMSAI 8080

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ClassicHasClass
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A childhood dream comes true: IMSAI 8080

Unread postby ClassicHasClass » Mon Apr 06, 2015 3:24 pm

My IMSAI 8080 arrives this week, complete with various RAM cards and a TDL SMB (system monitor/cassette/terminal) interface card, and of course the CPU. No broken toggles, some scuffing on the sheet metal lid which should be repairable, powers up, blinkenlights blinkelte. Price was a bit steep but I liked the card selection and the fact that the system would probably be functional out of the box.

This is my first S-100 system (that works -- I have an Alpha Micro S-100 box but I have no idea if anything in that thing works, it was in pretty bad shape when I got it). I'd like to set up at least a floppy system and maybe a video board. Is anyone selling any cards they'd like to get rid of? What do people recommend?

Should be here by Wednesday! I've wanted one ever since WarGames ...
smit happens.

:Fuel: bigred, 900MHz R16K, 4GB RAM, V12 DCD, 6.5.30
:Indy: indy, 150MHz R4400SC, 256MB RAM, XL24, 6.5.10
:Indigo2IMP: purplehaze, R10000, Solid IMPACT
probably posted from Image bruce, Quad 2.5GHz PowerPC 970MP, 16GB RAM, Mac OS X 10.4.11
plus IBM POWER6 p520 * Apple Network Server 500 * HP C8000 * BeBox * Solbourne S3000 * Commodore 128 * many more...

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Re: A childhood dream comes true: IMSAI 8080

Unread postby ClassicHasClass » Mon Apr 06, 2015 3:38 pm

Here are the cards in the unit, in case it makes a difference to suggestions:

Ithaca IA-2000 Z80 CPU card (with the AMD 9519 interrupt controller); http://www.s100computers.com/Hardware%2 ... Z80-II.htm
TDL SMB system monitor board wired to "video" and "tty" (the difference is that "video" doesn't support tape punch), with cassette interface and boot monitor; http://s100computers.com/Hardware%20Fol ... %20SMB.htm
Godbout/CompuPro Econoram XIIIa RAM board; the full 32K appears to be intact
TDL Z16 RAM board, 16K; http://s100computers.com/Hardware%20Fol ... %20RAM.htm

So at least 48K RAM onboard, which is probably as much as practical since I'd need addressing space for ROMs.
smit happens.

:Fuel: bigred, 900MHz R16K, 4GB RAM, V12 DCD, 6.5.30
:Indy: indy, 150MHz R4400SC, 256MB RAM, XL24, 6.5.10
:Indigo2IMP: purplehaze, R10000, Solid IMPACT
probably posted from Image bruce, Quad 2.5GHz PowerPC 970MP, 16GB RAM, Mac OS X 10.4.11
plus IBM POWER6 p520 * Apple Network Server 500 * HP C8000 * BeBox * Solbourne S3000 * Commodore 128 * many more...

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Re: A childhood dream comes true: IMSAI 8080

Unread postby guardian452 » Mon Apr 06, 2015 4:28 pm

I love these old machines! Never had one, and the prices make a homebrew 8bit just as reasonable.

Which could be a good possibility for a floppy controller or video board, you can always make your own from a published kit. There must be a couple to choose from for S-100 systems.

Congrats!
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Re: A childhood dream comes true: IMSAI 8080

Unread postby commodorejohn » Mon Apr 06, 2015 10:05 pm

Oh drool. I'll have to post when I get the Jupiter-6 I've got lined up, just to avenge my jealousy... ;)

See if you can line up some kind of music board (there were a few for S100, though I don't have any specific suggestions.) Nothing like that early computer music...
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Re: A childhood dream comes true: IMSAI 8080

Unread postby ClassicHasClass » Mon Apr 06, 2015 10:27 pm

the prices make a homebrew 8bit just as reasonable.


I don't know if reasonable is the word I'd use: as far as I'm concerned, if I'm going homebrew I'd rather just use an emulator unless I really need the hardware to exist physically. But given how I much I paid for this I understand the sentiment ;)

It's nice to have a real piece of history, and everyone has been really excited to see "the War Games computer."

commodorejohn wrote:Oh drool. I'll have to post when I get the Jupiter-6 I've got lined up, just to avenge my jealousy... ;)

See if you can line up some kind of music board (there were a few for S100, though I don't have any specific suggestions.) Nothing like that early computer music...


The JP-6 is indeed a very nice synth, though if I need a programmable sound I'm kind of spoiled by just telling the SID in the C128 to do it ...

The SMB does have a cassette interface, but that's kind of a drag. The problem is I don't know what floppy controllers will "just work" with this (and, more to the point, what kind of drives will "just work" with the controller). I don't want to be toggling boot commands in by hand every time I power the damn thing up and I don't know enough yet about the architecture to burn an EPROM it will use as boot code. The C128 is a nice CP/M machine but having the IMSAI boot CP/M as well would be fun too.

While I'm dreaming, I'd like a Cromemco Dazzler, too. And a pony.
smit happens.

:Fuel: bigred, 900MHz R16K, 4GB RAM, V12 DCD, 6.5.30
:Indy: indy, 150MHz R4400SC, 256MB RAM, XL24, 6.5.10
:Indigo2IMP: purplehaze, R10000, Solid IMPACT
probably posted from Image bruce, Quad 2.5GHz PowerPC 970MP, 16GB RAM, Mac OS X 10.4.11
plus IBM POWER6 p520 * Apple Network Server 500 * HP C8000 * BeBox * Solbourne S3000 * Commodore 128 * many more...

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Re: A childhood dream comes true: IMSAI 8080

Unread postby Alver » Tue Apr 07, 2015 1:20 am

ClassicHasClass wrote:While I'm dreaming, I'd like a Cromemco Dazzler, too. And a pony.

From experience: ponies are not worth it. All they do is eat and poop and poop and eat. :mrgreen:
while (!asleep()) sheep++;

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Re: A childhood dream comes true: IMSAI 8080

Unread postby smj » Wed Apr 08, 2015 9:28 pm

ClassicHasClass wrote:I've wanted one ever since WarGames* ...

* Ally Sheedy not included in purchase price. :P


There are a few folks using IMSAIs on the N8VEM S-100 mailing list. Andrew Lynch (N8VEM) and John Monahan have produced a silly number of new-design S-100 boards, including floppy and IDE controllers, and other folks have started bringing out their own. Start with this PBworks "wiki" page and check the S-100 list/group here on Google Groups.

If you don't already have links to folks/groups running CP/M, you can find some there with a little poking around.
Then? :IRIS3130: ... Now? :O3x02L: :A3504L:- :A3502L: :1600SW:+MLA :Fuel: :Octane2: :Octane: :Indigo2IMP: ... Other: DEC :BA213: :BA123: Sun, DG AViiON, NeXT :Cube:

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Re: A childhood dream comes true: IMSAI 8080

Unread postby nekonoko » Thu Apr 09, 2015 9:50 am

smj wrote:There are a few folks using IMSAIs on the N8VEM S-100 mailing list.


Yep, I have 3 IMSAI 8080s and I'm on there as well. I also have about 30 IMSAI binders containing most of IMSAI's interoffice communications from their last two years of business - interesting stuff.
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Re: A childhood dream comes true: IMSAI 8080

Unread postby ClassicHasClass » Thu Apr 09, 2015 5:08 pm

So it came, and it doesn't appear to be working ... :(

I carefully checked everything before powering it on with no cards, and the front panel appears to light (but does weird things, to be mentioned).

Next I tried installing the CPU board. The Ithaca board has a 20-pin header for the front panel, but the panel connector has 16 pins. I guessed that it went in the rightmost 16 and it resets, runs and stops, at least. I powered it on with all the address toggles on zero. If I press EXAMINE NEXT, it advances its address bus lights. I didn't try to do anything else at this point.

Next I tried installing the Z16 board since I had a good guess that mapped to the bottom of memory. Here's where it gets weird. Going through memory with EXAMINE NEXT, data bits 0 and 6 light alternately. If I try to store with DEPOSIT, nothing is stored. Plus, some of the address lines now stick high, which may be why I can't store anything since they're indicating addresses outside of the Z16 addressing range. Toggling the switch makes no difference.

Ideas?
smit happens.

:Fuel: bigred, 900MHz R16K, 4GB RAM, V12 DCD, 6.5.30
:Indy: indy, 150MHz R4400SC, 256MB RAM, XL24, 6.5.10
:Indigo2IMP: purplehaze, R10000, Solid IMPACT
probably posted from Image bruce, Quad 2.5GHz PowerPC 970MP, 16GB RAM, Mac OS X 10.4.11
plus IBM POWER6 p520 * Apple Network Server 500 * HP C8000 * BeBox * Solbourne S3000 * Commodore 128 * many more...

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Re: A childhood dream comes true: IMSAI 8080

Unread postby smj » Thu Apr 09, 2015 5:11 pm

nekonoko wrote:I also have about 30 IMSAI binders containing most of IMSAI's interoffice communications from their last two years of business - interesting stuff.

Holy control panel! Assuming this "new" duplexing Fujitsu scanner checks out, I'll find a day to drop it off where ever you are around Pleasanton, if you need one to start scanning the contents of those binders... ;)
Then? :IRIS3130: ... Now? :O3x02L: :A3504L:- :A3502L: :1600SW:+MLA :Fuel: :Octane2: :Octane: :Indigo2IMP: ... Other: DEC :BA213: :BA123: Sun, DG AViiON, NeXT :Cube:

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Re: A childhood dream comes true: IMSAI 8080

Unread postby nekonoko » Thu Apr 09, 2015 5:42 pm

smj wrote:Holy control panel! Assuming this "new" duplexing Fujitsu scanner checks out, I'll find a day to drop it off where ever you are around Pleasanton, if you need one to start scanning the contents of those binders... ;)


I have a lot scanned already, but I haven't found time to clean them up. I'll upload the raw PDFs I have to Dropbox - they should start showing up here: https://www.dropbox.com/sh/15j4zu92k5di ... HpSla?dl=0
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Re: A childhood dream comes true: IMSAI 8080

Unread postby pentium » Thu Apr 09, 2015 7:24 pm

You're lucky. Really lucky. I spent over a decade trying to get one of those machines and only recently settled on a $650 AltairClone as the original machines are now fetching over $2000. It will need a number of modifications before it will be ready to accept an S100 backplane.

Also, Cromeco Dazzler's aren't that complex. I'm sure if you can come across someone willing to make some really high quality scans or photographs you can probably make new boards and order in the necessary chips. It's all 7400 logic. I'd be in for a set of empty boards if that idea ever floats.

Edited: It looks like all the information you require is in the "Cromeco Dazzler Schematic and Foil Diagrams", which I have yet to find in PDF format, but there's also a decent amount of information in the manual which will go a long way towards manufacturing new boards.
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Re: A childhood dream comes true: IMSAI 8080

Unread postby nekonoko » Thu Apr 09, 2015 10:02 pm

I'd be more than happy with a reproduction Dazzler myself. The other card I really, really want is a Jade bus probe - they go for crazy money when they show up on eBay.
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Re: A childhood dream comes true: IMSAI 8080

Unread postby ClassicHasClass » Sat Apr 11, 2015 5:50 pm

I'm thinking it's stuck or marginal front panel switches. I was able to get the EconoRAM to store some words finally today.

http://www.floodgap.com/iv/2500

However, that AltairClone is intriguing. Shame it isn't really S-100, though it would seem to handle all the basics in emulation. It would also be nice if it were available in a smaller form factor.
smit happens.

:Fuel: bigred, 900MHz R16K, 4GB RAM, V12 DCD, 6.5.30
:Indy: indy, 150MHz R4400SC, 256MB RAM, XL24, 6.5.10
:Indigo2IMP: purplehaze, R10000, Solid IMPACT
probably posted from Image bruce, Quad 2.5GHz PowerPC 970MP, 16GB RAM, Mac OS X 10.4.11
plus IBM POWER6 p520 * Apple Network Server 500 * HP C8000 * BeBox * Solbourne S3000 * Commodore 128 * many more...

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Re: A childhood dream comes true: IMSAI 8080

Unread postby nekonoko » Sat Apr 11, 2015 8:31 pm

ClassicHasClass wrote: It would also be nice if it were available in a smaller form factor.


If you're looking for a small form factor, this is what you want: http://www.brielcomputers.com/wordpress/?cat=18
Twitter: @neko_no_ko
IRIX Release 4.0.5 IP12 Version 06151813 System V
Copyright 1987-1992 Silicon Graphics, Inc.
All Rights Reserved.


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