Talk:IMSAI 8080

Memory size

The infobox says there was 256 bytes of RAM and a BASIC interpreter. Is this correct? How on Earth can a BASIC interpreter run in 256 bytes? There would be enough space for about 5 lines of code in memory. Actually, scratch that, how can you run CP/M in 256 bytes, when the CPM Memory Map requires the low 256 bytes of memory to be reserved for system data...? JulesH 20:49, 17 February 2007 (UTC)

• well...I'm trying to remember if the original kit came with any memory boards at all. I kinda think not; you'd buy a 4K board or an 8K board separately. --jpgordon^∇∆∇∆ 07:55, 18 February 2007 (UTC)

I think 256 bytes was the standard, then you added more as expansion cards?. The specs are from http://www.old-computers.com/museum/computer.asp?c=389&st=1 — Wackymacs 08:53, 18 February 2007 (UTC)

The first IMSAI ad in BYTE magazine (Jan 1976, page 40) stated 256 bytes on a 4K board. The original IMSAI ad in Popular Electronics (Oct 1975 page 110) stated 1K on a 4K board. (You need a magnifying glass to read this 1/6 page ad.) -- SWTPC6800 (talk) 03:01, 19 December 2007 (UTC)

Front panel story...

This latest edit has some problems:

1. Front panels with switches and lights were hardly archaic; most computers had them at that time
2. The bootstrap loader was hardly tedious to load; thirty years later, my fingers still have the muscle memory to automatically key it in. Something like 21 00 01 DB FE E6 7F C2 03 00 DB FF 77 23 C3 03 00. That's all.
3. Core dumps aren't necessary if you have a front panel; that's the whole point. All of memory could be examined from the front panel.
4. What "certain toddler"?
5. What do you mean "keyboard interface"? The thing was generally connected to either a teletype, or to a CRT (often an ADM-3A, the cheapest ones around); alternately, keyboard were connected to (I forget which port) and the rudimentary video cards were used (there was a black and white one, but there was also the Cromemco Dazzler for fancy color play.)
6. Who are these engineers that were fired?

I'll be removing this section if these issues aren't clarified. --jpgordon^∇∆∇∆ 16:09, 10 November 2007 (UTC)

Early IMS advertisements

The first ads for IMS Associates, Inc. appeared in the April 1975 issue of Popular Electronics on page 90. The one inch high ad was for the 7400 Series TTL Pinout Handbook that sold for $2.95. The street address was 1298 E 14th St. San Leandro, Cal. The same ad ran each month through the September issue. The October 1975 issue had a 1/6 page ad that lists the IMSAI 8080 computer and many accessories. (Printers, floppy disk, and even a 50 MB hard disk controller.) It also mentions the Pinout Handbook. The December 1975 issue has a 2/3 page, easy to read, ad.

The fist ad in BYTE was a full page showing a picture of the IMSAI 8080 computer. (January 1976 page 40) -- SWTPC6800 (talk) 04:02, 19 December 2007 (UTC)

Umm, something is very odd here

As the article is currently worded, it is implied that the IMSAI was developed as an internal project at IMS, and released just after the Altair. This is clearly not true - the IMSAI was based on the Altair's S-100 bus, something the linked-to reference states (although in confusing fashion). I consider this article to be very misleading. Maury Markowitz (talk) 22:27, 17 December 2008 (UTC)

Perhaps I'm confused. The only place the article mentions the Altair is in the second sentence, which reads, "It was compatible with its main competitor, the earlier MITS Altair 8800, by which it was inspired.". --jpgordon^∇∆∇∆ 00:37, 18 December 2008 (UTC)

That's my point: this machine was a clone of the Altair in every sense of the word, it was copied directly from the earlier machine. Yet this is not mentioned once in the history. In fact, the history implies that it was designed entirely in-house, as if it "just happened" to end up exactly like the Altair. Maury Markowitz (talk) 13:14, 18 December 2008 (UTC)

The article refers to it as a clone. Doesn't that mean a copy? --jpgordon^∇∆∇∆ 14:55, 18 December 2008 (UTC)

Read the history section. I believe it makes it sound like the computer was developed as an internal project, with no connection to the Altair at all. Do you disagree my statement? Maury Markowitz (talk) 20:20, 18 December 2008 (UTC)

It's kinda noncommittal. Do we have some good sources describing the design process? Certainly they lifted the S100 bus intact. --jpgordon^∇∆∇∆ 21:04, 18 December 2008 (UTC)

From the mid-70s as an early IMSAI hobby-builder, I remember strong advocacy of maintaining the "S-100 Bus" as a standard in order to provide a common interface for development of independent boards and computers. Thus copying the "S-100 Bus" was clearly considered a worthy objective, and there were in-fact a proliferation of S-100 boards produced. Later it was determined that the S-100 pin assignments had some design problems, and all the other proprietary buses evolved, to the detriment of that dream. HalFonts (talk) 13:55, 20 January 2014 (UTC)

Imsai 8080 series 2 project seems to have died out

https://www.imsai.net/products/imsai_series_two_project.htm

Source indicates last update as 2010 (speaking in 2017), several google talk threads indicate no response to emails. Series two project presumed dead. Proof of existing sold and delivered units or more recent communications then 2010 not found. Suggest subtopic be updated. — Preceding unsigned comment added by 80.114.168.224 (talk) 22:55, 9 November 2017 (UTC)

Seems dead. I've removed the section. --jpgordon^{𝄢𝄆 𝄐𝄇} 23:20, 9 November 2017 (UTC)