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Floppies_only
May 26th, 2008, 03:43 PM
Gang,

It looks like somebody is attempting to resurrect the IMSAI computer by designing an S-100 computer with a Z80 processor and a USB adaptor to scan the programmer's switches and light the L.E.D.s. Here's the website:

http://www.imsai.net/products/imsai_series_two.htm

It looks like the project is going pretty slow. I am excited by the prospect of a computer that has flashing lights (anybody remember "20,000 Leagues Under The Sea"?) but I suspect that the learning curve required for me to get an old IMSAI running is too steep.

I was wondering if anybody could point me to books that I could buy on the used market at Amazon.com that would let me see what you could do with an IMSAI.

I think that it would be cool to write USENET posts with a word processor on one and then transfer the info to a computer connected to the internet. Keep in mind that it's not unheard of for me to take a couple of hours to write a good post. Sometimes several days.

Anybody?

Thanks,
Sean

P.S.: Could anybody tell me what kind of terminals used to be used with S-100 computers, and what (if any) disk drives?

NobodyIsHere
May 26th, 2008, 05:07 PM
Hi,
Before you send in any money for an IMSAI II, I recommend you read this USENET thread carefully...

http://groups.google.com/group/comp.os.cpm/browse_thread/thread/cc687393d9af8e62/4422b3cdf6f48170?#4422b3cdf6f48170

Caveat Emptor! Thanks!

Andrew Lynch

Floppies_only
May 26th, 2008, 05:44 PM
Hi,
Before you send in any money for an IMSAI II, I recommend you read this USENET thread carefully...

http://groups.google.com/group/comp.os.cpm/browse_thread/thread/cc687393d9af8e62/4422b3cdf6f48170?#4422b3cdf6f48170

Caveat Emptor! Thanks!

Andrew Lynch

Yeah, I should have said that I thought that it would be a bad idea to "buy" one of these until he claims to have working units ready to go out the door. You can tell from the website that the programing hasn't been completed and the documentation is just a gleem in his eye.

But he gave me an idea. I think that a USB peripheral for a modern IBM PC that lights L.E.D.s to show the register, address counter, and memory contents would be cool. I think that it would also help if the program that sent the signals to the panel slowed the computer down so that you could see the lights flash.

Sometimes I like just watching the L.E.D.s flash :)

Sean

ziloo
May 27th, 2008, 04:46 AM
...Sometimes I like just watching the L.E.D.s flash ...

welcome to the club!!! :biggrin:

ziloo

MikeS
May 27th, 2008, 06:57 AM
Hi,
Before you send in any money for an IMSAI II, I recommend you read this USENET thread carefully...

http://groups.google.com/group/comp.os.cpm/browse_thread/thread/cc687393d9af8e62/4422b3cdf6f48170?#4422b3cdf6f48170

Caveat Emptor! Thanks!

Andrew Lynch
---------
Here's your opportunity, Andrew! A front panel with lots of switches and LEDs and maybe even a few 7-segment displays to plug into your Z80 SBC bus.

What's been happening with Mr. Fisher & the IMSAI II lately? Haven't heard from/about him for a while.

And wasn't Howard H. going to build something? What happened to that?

And of course there are Grant's Altair replicas for those with $$s looking for switches and lights.

m

NobodyIsHere
May 27th, 2008, 07:53 AM
Hi,

The SBC does have a single power indicator LED but no flashing lights or bells. However, the ECB debugger board *does* have lots of flashing LEDs for the address, data, and control bus states. That might do it for some but it is not as extensive as an Altair or IMSAI front panel. My plan is to add RESET and SINGLE STEP toggles but that is it. It would probably be closer to a highly simplified Jade Bus Probe or something similar.

I suppose a keypad/display board would be possible to design but it is not on my list to do since there are already several peripherals which are higher priority (ECB backplane, bus debugger, Disk IO, etc). Especially since the SBC pretty much assumes some sort of terminal, which will most likely be a PC running a terminal program, is used for debugging and interaction.

Blinkenlights are useful during the software debug stage but lately I have been just using the oscilloscope or logic probe instead. One *major* caveat though... the SBC is EBC based, not S-100. That is a whole another thing entirely!

We'll see how the SBC goes. Thanks!

Andrew Lynch

Floppies_only
May 29th, 2008, 05:36 PM
And of course there are Grant's Altair replicas for those with $$s looking for switches and lights.

m

"Reservations for the next run of 20 units may be made now."
--http://altairkit.com/

Sean

Floppies_only
May 29th, 2008, 05:49 PM
welcome to the club!!! :biggrin:

ziloo

Back when I was learning with my Science Fair Microcomputer Kit
(http://www.old-computers.com/MUSEUM/computer.asp?st=1&c=1053) I wrote a program to step through memory, display the contents of the memory byte on the eight L.E.D. display, pause, and then repeat.


Sean, who still says he's just an "appliance operator"

Sharkonwheels
May 30th, 2008, 12:13 AM
Only thing, is, the last Altair to go on eBay was $1585, and the one before was like $1600-1700.

At that price, it's not worth getting a clone, as the real deal will have more future value. The price tanked on them, because I think there was a "sprint" of collectors getting them to have one in their collection for a couple of years, and now the market has become more sane on them. Even Imsai's can be had for under $1000 if you exercise a little patience.

Keep in mind this has no bearing on the quality of Grant's stuff - from what I have read/heard, it is top-notch, and probably of higher build quality than the original!

'nuff said on THAT subject - nice job, Grant!


T