Very interesting ! I never saw a CPU upgrade card that actually had the removed 8088 plugged back into the Upgrade card.
Will look around but do not think will find anything. You might PM feipoa as he has worked with more cpu upgrade cards than anyone AFAIK.

Horun wrote on 2021-03-24, 02:57:

Very interesting ! I never saw a CPU upgrade card that actually had the removed 8088 plugged back into the Upgrade card.

I think for XT accelerators that is actually a norm rather than exception. The odd thing here seems to be a lack of a hardware turbo switch

Will look around but do not think will find anything. You might PM feipoa as he has worked with more cpu upgrade cards than anyone AFAIK.

Thanks, will do!

Maybe you switch between processors using one of the typical key combinations used for switching between turbo and deturbo mode on other machines?

Doornkaat wrote on 2021-03-24, 10:42:

Maybe you switch between processors using one of the typical key combinations used for switching between turbo and deturbo mode on other machines?

That is definitely how it’s done, but judging by the Tandy model of the card, you need to either load a .sys driver or use a utility for that. I don’t think this card has a BIOS of its own.

Unfortunately, I have never used this accelerator card before. User Anonymous Coward has pretty much tested every 286 upgrade known to exist. I think he's your best bet for info.

jheronimus wrote on 2021-03-24, 10:53:

Doornkaat wrote on 2021-03-24, 10:42:

Maybe you switch between processors using one of the typical key combinations used for switching between turbo and deturbo mode on other machines?

That is definitely how it’s done, but judging by the Tandy model of the card, you need to either load a .sys driver or use a utility for that. I don’t think this card has a BIOS of its own.

Oh, ok. You can probably tell I have next to no clue about those cards.😅

Still waiting for the card, but in the meantime it has dawned on me. Here's another photo of the card:

I thought the 8088 should be piggybacked into the end of the cable that goes into the motherboard CPU socket, but apparently it is not. The socket on the card is for the 287 FPU. So the card only has one CPU and as such doesn't need to switch between the two.

Furthermore, I've found a review on the original PCT 286 Express card, and it specifically mentions that the card didn't come with any driver disk:

So, the good news is that I don't need to find any software for the card. The bad news is, of course that if it works, I'm going to lose XT compatibility. My 1000SX does have original Tandy DOS3.2 installed with a modified mode.com utility that can slow the CPU down, and it worked reasonably well even with a V20, though.

heheh yeah I had never heard of one that you put the 8088 in to the upgrade but have very limited experience with the old XT cpu upgrades.
Well is good you do not need a driver and think most back then would have bought the upgrade (instead of buying a new computer) to run Windows 2 or newer apps on it and not for old XT style gaming... just a thought.

Did you find out more about this card @jheronimus ? i have this exact same card, and also need jumper settings and documentations on it 😉

Nah, I didn’t. But I’ve posted a review that says it didn’t come with any drivers. Jumpers remain a mystery, though

@feipoa do you know this Verbatim Data Life CPU Card ? or has some dokumentation on them?

So thought I'd do a short write-up on everything I've managed to find on this board so far

1) it did not come with any software and doesn't have any way to switch the speed. Apparently this was a selling point (easy setup, high compatibility)
2) it comes with an 8 MHz Siemens 80286-R. Next to the 287 socket there's a jumper for 5 or 8 MHz operation
3) it is a "synchronous" card, meaning that it runs at the speed of the bus and does not have its own clock generator
4) it is compatible with EGA videocards (so I suppose, VGA too?)
5) it comes with non-replaceable 8 kb of cache. The jumpers on the right side of the board set the cache on/off, but the rest of the jumpers adjust for the amount of RAM installed in the system. By default the card is set for 256KB, but adjusting the jumper should set it for up to 640KB. No idea if these settings matter with cache disabled. No idea if any of the jumpers in that block do anything else

Right now I'm trying to get it to work in an 8MHz XT motherboard with an ATi Mach8 VGA card set for 8bit operation. The CPU gets warm, but no matter what I do with the cache/memory settings it does not POST. The CPU does get warm though.

I think I'll try the system with an EGA-only card soon just to eliminate videocard incompatibility.

Oh damn, tried it in a different motherboard and it worked. No idea what was the culprit. At first it refused to boot too, after I randomly tried removing 287 from the board the Racecard just started. Returned the 287 — still works. But not on the other 8 MHz board. The cache or 287 clock jumpers seem to do nothing either way.