Microsoft open sources GWBASIC

Mike Stein mhs.stein at
Thu May 28 18:36:31 CDT 2020

Is nobody going to mention the cute little MC-10 (the only R-S computer I ever owned, briefly, aside from the M100), purportedly the cheapest colour-capable computer at the time ?


----- Original Message ----- 
From: "Jim Brain via cctalk" <cctalk at>
To: <cctalk at>
Sent: Thursday, May 28, 2020 4:54 PM
Subject: Re: Microsoft open sources GWBASIC

> On 5/28/2020 12:38 PM, Liam Proven via cctalk wrote:
>>> Yes.  TRS80.
>>> It had a memory map that was incompatible with CP/M.  BASIC in ROM at the
>>> bottom, and RAM at the top.
>> Which one?
>> As they're purely a theoretical concept to me and AFAIK I've never
>> actually touched one, the profusion of models is very confusing, and
>> I'm  not aware of an idiot's single-para overview.
>> I vaguely know of:
>>   • TRS-80 Model 100 (8085), pre-laptop portable
> Rebadged Kyotronic 85. Was pretty well received in US by journalists 
> and those who needed some computing power on the go.
>>   • Tandy 1000 (PC compatible)
> Yep, there's a whole line (HX, LX, EX, etc.)
>>   • TRS-80 Model 2000 (*before* the 1000?! Also kinda-sorta PC
>> compatible, nearly?)
> Maybe due to other vendors having a "1000" machine, this put Tandy in 
> front. Or, depending on what the Tandy 6000 was introduced, maybe they 
> had a product lineup dreamed...
>>   • TRS-80 Colour, AKA CoCo -- 6809
> Started life as a farming-related Videotex terminal. Pics will show the 
> amazing similarity. Was a joint venture between Motorola and Tandy, and 
> used essentially the 6809 reference design.
>>   • TRS-80 Pocket (no idea)
> These were all rebadged items from other manufacturers (PC-1,II,34, 
> etc..). Went all the way up to 8. But, folks prefer the 2, as it was 
> most expandable, etc.
>> Then there seem to be about 42 different computers called TRS-80 Model
>> X where X is either a Roman or Arabic number under 1000, after which
>> it all changed. Except 2000 comes before 1000. Obviously.
> Al PC compatibles.
>> The TRS-80 Model I, Model II, Model III, Model 4, Model 12, Model 16,
>> etc. I know nothing at all about these but I believe the III ran Xenix
>> on a 68000 and had some resemblance to the Apple Lisa, which would
>> seem to preclude any relation to the Model I & Model II -- and
>> Wikipedia suggests that the Model II is totally different from the
>> Model I.
> IN the beginning, there was the Model 1 (actually, it was called the 
> Micro Computer System at intro. It got back-numbered when the II came 
> out). It was a fat KB shell with a computer board in it (think C64, but 
> less aerodynamic :-) Fred's right, it should be considered a home 
> computer. No color, Z80 1.7MHz (half the 3.59MHz of NTSC TV signal fame).
> FOr the business crowd, TANDY designed the Model II, which is 
> distinctive due to the 8" drives used. In fact, I think it's the only 
> mainstream US computer offered with such drives straight from the 
> factory, though someone will correct me if not.
> Enter the FCC, and the 1981 regulations concerning EMI. The Model I 
> didn't pass muster, so the Model III (which was mainly an extension of 
> the Model I specs, but in a nicely polished case, including monitor and 
> drives. It's what people think of when they remember the TRS-80 
> computers, I think.
>> But it claims the Model III is compatible with the Model I. (Wut?)
> Yep, and the 4 was a follow on from the 3.
>> It very quickly all becomes rather surreal and I rapidly lose track
>> (and interest, TBH.)
>> I suspect a graphic might be needed to disentangle it.
>> So it goes:
>> Model I → Model III → Model 4
> 1-3-4-4p
>> *And*
>>>>    Model 2 → Model 12 → Model 16
> II-16A
> II-12/16B (16B had the card cage)
> I see the 16A and the 12/16B as different sublines, as the II/16A used a 
> passive backplane with cards, while the 12/16B/6000 had a motherboard 
> with the z80 on it, and the card cage was for extensions (and the 68K card).
> Both sublines merged back together with the 6000
> Units were Z80 based, but a 68K daughtercard was sold to enable Xenix. 
> The 6000 has an 8MHz 68K, I think the rest are 6MHz
>> ... ?
>> Where do the VideoGenie and Coco fit in?
> VideoGenie is not a TANDY item (most folks consider it a clone of the 
> Model I), and the Coco was a different home computer line with color.
> -- 
> Jim Brain
> brain at

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