VOGONS


First post, by Dosler

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Newbie

Hello everyone, I need your help repairing an accelerator card. I acquired the card—along with its manual—in excellent cosmetic condition, though it was missing the specific cable required for the 8088 CPU socket.
I managed to cobble together a makeshift replacement cable for the time being. Next, I removed the V20 CPU from my XT system and installed it onto the accelerator card. Unfortunately, the system failed to POST; the screen remained black. However, with the original Intel 8088 CPU installed, a POST screen appears, and the system boots up without any further issues. (Could this be a timing issue?)

There are two switches located on the card's slot bracket: the lower one (positioned closer to the ISA slot) toggles the cache on or off, while the upper one activates "Turbo Mode" (286 mode). Regrettably, I have been unable to get the card to function in Turbo Mode. There is no POST, no beep—absolutely nothing.
Just to be safe, I also swapped out the 286 CPU, but that made no difference. I was, however, able to successfully measure the clock frequency at the 286 chip.

The card also features three PAL chips. What are your thoughts on this? Is it possible that these chips have lost their programming, even though they are One-Time Programmable (OTP) devices?

Does anyone else own this card or have any experience working with it? Would anyone happen to have the capability to read out the contents of these PAL chips for me, so that I can compare them against the contents of the chips currently on my card?
I would really hate to give up on this fine piece of hardware.