IMSAI

[vbriel]

I am happy to announce that Thomas Fischer and I have reached a tentative agreement for me to acquire the IP and remaining inventory of IMSAI. With this purchase, Thomas will support me on getting the series 2 computer system completed and into production. This is a big deal and a big responsibility to take over an icon like IMSAI.

The plan to raise the funds to purchase IMSAI involves using Kickstarter, a crowd funding website created just for this purpose. I will be asking for donations in any denomination in order to "Save IMSAI". With your help we can make history and reboot the IMSAI. More details will follow in the near future as we prepare the Kickstarter page. Anybody that has done business with me knows how I treat my customers. Thomas feels I am the perfect candidate to take over IMSAI and keep the legacy going. I am asking for everybody's help on this, I can't do it alone. Stay tuned, once the Kickstarter page is ready I'll post a link and we will see if we can't make this a reality. Really would like feedback on this, good, bad or indifferent doesn't matter.

Vince

[tranter]

Very interesting. I had no idea IMSAI was still alive but I see there is a web site at http://www.imsai.net/ including some info on The IMSAI Series Two Project. That could be a good fit with the other replica kits you offer. I hope it can be offered at least in part as a kit as well as fully assembled.

(I wonder if I should start hoarding all the S-100 boards I can find on ebay in hopes that their value will soon be going up?

[bibrex]

SAVE IMSAI, Vince !!!

All systems are GO !!!

I will gladly make a donation.

[vbriel]

Kits are what I do now. Assembled is offered for those who don't want to deal with a kit or just can't solder for whatever reason. Trust me, I prefer kits, they are easier to deal with. The series 2 is a fit to that Altair PC I was going to do years ago but never happened.

[bibrex]

Looking forward to seeing it come to life.

[sje]

Having built an IMSAI 8080 back in 1976, I can give my approval for this idea. But I have some concerns. Is the system to be offered close to the original product (other than safety related changes to the power supply)? Compare this with the Altair kit offered by Grant Stockly who seems to be getting back in the game.

[vbriel]

The series 2 prototypes had both S100 and PC motherboards in them. They used 650W ATX power supplies with an adapter to boost the voltage up to the required amount for S100 standards. So, it will be like Grant did with the Altair except the IMSAI series 2 can be both machines. It means it can be customized for your needs. This part is already finished, there are just some other things to hammer out on it.

[Bill Loguidice]

Great news, it will be in the right hands. Hopefully some of the Kickstarter options involve purchasing complete systems!

[bibrex]

...except the IMSAI series 2 can be both machines. It means it can be customized for your needs.

Do you mean that it could also be built to look like an Altair 8800 front panel?

[Kevin Adams]

Hi Vince,

This is great news!

You're just the guy who could pull this off. I'll contribute to the kickstarter, and very much want to buy the kit!

Kevin

[jgalinat]

Hi Vince,
This is absolutely great. I built an IMSAI in 1977, it was the first kit that I ever built and was amazed that it worked first time. I sold it in the mid 80's and have regretted it ever since. I have built your micro Altair and your Micro Kim and know the quality products that you provide. I have been accumulating S-100 boards over the past couple of years and have 2 CPU boards that would work with an IMSAI front panel assuming that the updated front panel works & is connected to the CPU like the original. I have been following the imsai.net website for a few years and was dismayed to see that the project stalled. I am mainly interested in a straight S-100 configuration as I am more interested in how we did things in the past rather that a modern PC motherboards hybrid. Of course If I get the large enclosure, I could always add the PC motherboard at a later date. The success of your other products shows there is a large demand for retro systems. S-100 enthusiasts will be able to have more options for a front panels machine without spending a fortune at auction. I will support your kickstart project. Please make this feasible for hobbyist's everywhere.
Thank you,
Jeff Galinat

[sje]

Four items:

1) I don't think there is that much of a need for a separate, internal full PC board.

2) As I had read, the proposed IMSAI does not use an 8080 CPU, but rather one of the evolved Zilog designs with 20 bit or 24 bit addressing and a not strictly compatible instruction set.

3) Because of not having an 8080 CPU, there are questions about which signals and voltages were to appear on the bus and how these differ from the original.

4) In the original IMSAI 8080, there are several signals sent between the CPU board and the front panel which run on a separate cable bus. How will these be handled if there's no 8080 CPU or if there are other substantial differences?

[jgalinat]

Hi sje,
Regarding your points made on your last post, I read the IMSAI.net website description differently. The 8051 derivative is not the the "CPU" but it is present to drive the front panel LEDs, read the switches & interface the front panel to a PC motherboard if present (via USB).

Please see the pictures at http://www.imsai.net/products/imsai_series_two_project.htm . The left picture for the "short chassis" (a few pics up from the bottom) shows a ribbon cable going from the front panel to the CPU board. This was how the original IMSAI design did it via a 16 conductor ribbon cable via DIP sockets on both boards. The original front panel was a fairly complex design with a lot of one-shots and timing issues. I think that using an 8051 derivative simplified the design and allowed more interfacing flexibilty via USB.

I realize that my assumptions may be wrong so I am looking to Vince to explain the finer points of the design as I would like a S-100 machine with a working front panel for my collection and hopefully this will fill the need.

Regards,
Jeff

[sje]

What needs to be specified is the extent of interoperability between the old hardware and the new. If one had old IMSAI hardware, could any of the boards (including the front panel and the CPU card) be inserted into a new system and then work?

The 8051 was out of date twenty years ago; much better to use an AVR chip for a front panel as Vince has used one to run the entire mini-Altair emulator.

[galaga]

this is very good news hopefully a dream come true