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80386DX ISA single board microcomputer

alexandrugroza.ro

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Re: 80386DX ISA single board microcomputer

#131

Post by kjs3 »

jacquesm wrote: post #116
kjs3 wrote: post #95

Earlier quoted context omitted.

And if you're old and a bit odd, there were i486+i860[1] motherboards from (at least) Hauppauge, Microway & Olivetti. [1] https://old.hotchips.org/wp-content/uploads/hc_archives/hc02...

I never got my hands on one of those. But I did get to play with Transputers, which was another interesting co-processor option.

Transputers are still a thing from ST Micro, I think, though targeting the embedded market now. I got to use a Meiko 'Surface' transputer supercomputer back in the day. Interesting toy.

The i486+i860 combo I played with ended up being not particularly interesting. By the time it showed up, Pentium was eminent so the i486 was old news and the i860 was a huge pain in the ass to get anything like promised performance out of.

Re: 80386DX ISA single board microcomputer

#132

Post by jacquesm »

kjs3 wrote: post #131
jacquesm wrote: post #116

Earlier quoted context omitted.

I never got my hands on one of those. But I did get to play with Transputers, which was another interesting co-processor option.

Transputers are still a thing from ST Micro, I think, though targeting the embedded market now. I got to use a Meiko 'Surface' transputer supercomputer back in the day. Interesting toy. The i486+i860 combo I played with ended up being not particularly interesting. By the time it showed up, Pentium was eminent so the i486 was old news and the i860 was a huge pain in the ass to get anything like promised performance ou…

Meiko, there's another name that I haven't heard for a really long time.

Are there any Transputer based systems still in use?

Re: 80386DX ISA single board microcomputer

#133

Post by mahoro »

oso2k wrote: post #41
mahoro wrote: post #37

This is absolutely amazing and beautiful work. Congratulations to Alexandru! BTW can someone clarify what's the benefits of building the computer as an ISA board?

ISA boards (main, backplane and/or add-on) are relatively simple to design and interface. Not having to worry about north bridge and south bridge chips, PnP, PCI, AGP, VLB, EISA, MCA, etc. makes designs simpler. Many of the period correct sound card chips, VGA chips, Ethernet chips, serial and parallel chips are still available to design around. https://github.com/skiselev/isa8_backplane

Thank you

Re: 80386DX ISA single board microcomputer

#134

Post by mahoro »

jabl wrote: post #90
mahoro wrote: post #37

This is absolutely amazing and beautiful work. Congratulations to Alexandru! BTW can someone clarify what's the benefits of building the computer as an ISA board?

Probably because he previously designed an ISA backplane to plug it into: https://alexandrugroza.ro/microelectronics/system-design/isa...

This makes the project even more mindblowing, wow

Re: 80386DX ISA single board microcomputer

#135

Post by tssva »

TedDoesntTalk wrote: post #115
jonathanlydall wrote: post #82

Earlier quoted context omitted.

Only about 25 years too late :D, but that would have been cool to know about. It does make me think though about how I might have discovered such a thing at that point in time. I don't think I even had internet at home then, I never used things like a BBS and later I was never big into forums either. So the only way I really learnt things was either through fiddling (which is how I found out about the parallel cable…

> I guess I could have tried computing magazines Here are some offline methods other people used to get such information: 1. magazines and "zines" 2. books 3. word-of-mouth (as you said) 4. clubs or meet-ups Online methods that pre-date google: 1. newsgroups (usenet) 2. yahoo groups 3. bbses 4. forums 5. msdn 6. other search engines, even ones that used categories like yahoo were sometimes effective. It just took lon…

Byte Information Exchange (BIX) and CompuServe were also good online resources in the pre-Internet era.

Re: 80386DX ISA single board microcomputer

#136

Post by balls187 »

kjs3 wrote: post #95
jacquesm wrote: post #71

Earlier quoted context omitted.

And, for us oldies the Weitek as well as the DSP32 board. https://en.wikipedia.org/wiki/Weitek and https://www.signalogic.com/images/Ariel_DSP32-PC.jpg

And if you're old and a bit odd, there were i486+i860[1] motherboards from (at least) Hauppauge, Microway & Olivetti. [1] https://old.hotchips.org/wp-content/uploads/hc_archives/hc02...

I remember learning "Hauppauge" was pronounced "Hop Hog"

Re: 80386DX ISA single board microcomputer

#137

Post by balls187 »

ahefner wrote: post #5
balls187 wrote: post #4

I didn't realize Intel switched the meaning of DX/SX between their 386 and 486 CPU's.

How so? SX was always the crappy version.

Others have mostly answered it.

As a 486DX owner (IBM PC compatible AST Advantage), I was aware of the lower price point 486SX chip, and the difference was that the latter did not have hardware support for floating point calculations. In marketing jargon, the 486DX had an "integrated math co-processor."

I was also aware of the previous generation also using DX/SX designations, and until recently, assumed that the SX designation also meant a lack of a math co-processor, when instead, it simply meant a 16-bit data bus, compared to the 32bit data bus of the DX chip, and that neither DX or SX variant of the 386 had dedicated hardware for floating point calculations.

Re: 80386DX ISA single board microcomputer

#138

Post by kjs3 »

jacquesm wrote: post #132
kjs3 wrote: post #131

Earlier quoted context omitted.

Transputers are still a thing from ST Micro, I think, though targeting the embedded market now. I got to use a Meiko 'Surface' transputer supercomputer back in the day. Interesting toy. The i486+i860 combo I played with ended up being not particularly interesting. By the time it showed up, Pentium was eminent so the i486 was old news and the i860 was a huge pain in the ass to get anything like promised performance ou…

Meiko, there's another name that I haven't heard for a really long time. Are there any Transputer based systems still in use?

Yeah...the Meiko was pretty nifty, and Occam was an interesting language.

Like I said, ST Micro picked up the Transputer line via acquisition. They morphed it into more of an embedded product, and targeted things like set-top boxed. Pretty sure it was the ST20 line. Unfortunately, a very quick look at the web site makes it look like ST did what everyone else in the embedded world seems to be devolving to: everything is an ARM. So...there are probably descendants of Transputer still chugging along out there, but doesn't look like it has a future.

Re: 80386DX ISA single board microcomputer

#139

Post by dan_hawkins »

Sunspark wrote: post #113
dan_hawkins wrote: post #73

Earlier quoted context omitted.

A level of high voltage in CRTs is directly related to the size of tube and whether it's B/W (monochrome) or color (higher for color as you need to attract 3 electron beams instead of one.) In small monochrome CRTs (like 9"-10") cathode voltages would be in single digit kilovolts range, while for large color CRTs (19"+) would be in tens on kilovolts (like 25kV.) Bottom line is that in 9" CRT lower voltages are a bit…

I plan to replace some RIFA caps on a 9" monochrome that hasn't been powered on for years but was still working last time it was powered on. Do you know how long it takes for an old CRT like that to bleed out all the power if it doesn't have a circuit to automatically do that?

Minutes to tens of minutes (depends of voltage and air humidity.) Couple of hours would be on quite safe side. There's a simple procedure to quickly discharge HV of just turned off TV/monitor but I'd recommend that only for someone experienced working with high voltages.
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