Author Topic: Old IBM compatible PC/XT/AT cards  (Read 11197 times)

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Offline james_s

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Re: Old IBM compatible PC/XT/AT cards
« Reply #50 on: August 13, 2018, 07:13:40 pm »
I've always liked the IBM ATs. A few years ago somebody found a stash of NOS ATs still sealed in the box, I was really tempted to buy one but couldn't justify paying a few hundred bucks for something I don't need.

Offline rsjsouza

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Re: Old IBM compatible PC/XT/AT cards
« Reply #51 on: August 13, 2018, 08:45:19 pm »
At the time, math coprocessors were available from even more manufacturers than CPUs. Cyrix got its start making x87 coprocessors, and they were also available from Intel, AMD, IIT, Texas Instruments, Weitek, ULSI, Harris, and Xtend.

Also NEC (?) had a CMOS math chip for the 8088.  I put one in my Toshiba T1000 laptop (4.77 MHz 80C88).  The T1000 has the 768 KB memory expansion board which increases the RAM to 640K.  The rest of the memory is used as a RAM disk.    The T1000 is still ticking.  I just rebuilt the battery pack a couple of month ago.  I mainly use it as a terminal to Data I/O Unisite and 3980 device programmers

And yes, the PC/AT had a math chip and a 16 MHz crystal upgrade.   It has a 20 MB Rodime hard drive which now sounds rather iffy.
In my country (Brasil) the coprocessors were not readily available; Cyrix started to flood the market there only when their i387 was mainstream.

The PC-XTs in Brasil were mostly NEC V20s; much faster at 10.368MHz (IIRC) when compared to the regular 4.77MHz. Our 286, however, was a full blown 16MHz and the motherboard had SIPP memory interfaces.
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Offline rrinker

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Re: Old IBM compatible PC/XT/AT cards
« Reply #52 on: August 15, 2018, 03:00:59 pm »
 I swapped my 8088 with a v20 in my system - it was already an 8MHz 8088 so it was faster even without the NEC CPU, but the NEC one was even faster. I don;t recall (or at least it wasn't as readily available) NEC math coprocessor, I had an ordinary Intel 8087.
 Digging in a box of old chips (in anti-stat foam), I somehow still have the v20. I don;t think I would have bought 2 of them, and I last used the machine in the mid-90's when I donated it to the model railroad club I belonged to, complete with a couple of programs I wrote to keep track of membership and also manage the small store we ran. Can't imagine I would have swapped the CPU back, but obviously I did. Unless I came across a second v20 later on - I put the v20 and the 8087 in it when I was still in college, probably in '87.

I do remember STB, and particularly AST - one of the companies I worked for, we commonly sold AST servers.

Offline TheEPROM9

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Re: Old IBM compatible PC/XT/AT cards
« Reply #53 on: September 26, 2018, 08:26:34 pm »
Feel free to post pictures of your oddball vintage IBM PC/XT/AT compatible cards.

To get started, this is an old IRMA board used to interface the PCXT with an IBM 3270.

Yep that be my mystry card =-)
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Offline rich.holmteam

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Re: Old IBM compatible PC/XT/AT cards
« Reply #54 on: October 06, 2018, 05:19:41 pm »
Odd ball board.  Emulex DCP-286.  We used them for high speed async and sync market data feeds in the 80s and 90s.  In the late 1990s, everything switched to udp and tcp.


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