rasz_pl wrote on Today, 07:22:

analog_programmer wrote on Today, 06:31:

The Panatek PK-009 motherboard, that you're suggesting as a "matching board", looks like mine

Sorry. I assumed unknown-suntac-286 matched your board. Ill admit I didnt look at your picture because its bad quality 😀
imo Panatek PK-009 matches unknown-suntac-286. I resized and distorted images to match size and was flipping between them, the only difference I could spot was guard copper pours around mounting holes.

I just don't want another useless "[Unknown] (Suntac 286)" article with my board's pictures to pop-up on TRW site, so I didn't care to provide any hi-res quality pictures in the Predator99's thread. And the DIP-switches + jumpers "manual" I managed to compose is mainly for my own usage, since still no one has come out with exactly the same board, nor anyone shown any interest about it.

As for the Panatek PK-009 and the "[Unknown] (Suntac 286)" board from TRW site - if not a perfect match in their circuits, they look very similar to me, but there's no info about any jumper/DIP-switch settings on the unknown board, so we can only speculate for "a match".

rasz_pl wrote on Today, 07:22:

analog_programmer wrote on Today, 06:31:

, but only visually - there are some minor differences in the circuit and the components located "above" the crystal oscillator.

yours does indeed look different, that circuit might be 0 wairstates implementation, looks similar to whats in panatek manual.

Indeed. Close match, but not full match. And the most important difference - the mismatch in the DSP1 DIP-switches functions. That's why I din't pointed to Panatek PK-009.

And back to main topic. Last night I watched a YT-video from some "beaver" and he used some fast SOJ FPM RAM chips with his own ugly DIP-20 PCB adapters for VRAM upgrade (just faster chips, not more VRAM). So, it seems like I will have to look for SOJ DRAM chips with faster access times (possibly lower than 65 ns) and bigger volume + some suitable SOJ-26 to DIP-20 PCB adapters (I like these, but pcbYay became pcbNAY so far, so it's not an option to me for using these chinese PCBs making services anymore).

Or I have to look for slow SRAM DIP-20 (cache) chips, if there are any 512x4/1Mx4. I already know how to stop PIT Channel 1 refresh cycles and so the DRAM refresh cycles for these ancient PC systems, even if there's no such option in the BIOS.

analog_programmer wrote on Today, 08:00:

I just don't want another useless "[Unknown] (Suntac 286)" article with my board's pictures to pop-up on TRW site, so I didn't care to provide any hi-res quality pictures in the Predator99's thread.

but you didnt provide those here either 😀 you are the only person able to spot those differences

analog_programmer wrote on Today, 08:00:

Indeed. Close match, but not full match. And the most important difference - the mismatch in the DSP1 DIP-switches functions. That's why I din't pointed to Panatek PK-009.

you linked to unknown-suntac-286 and imo its 100% same board as panatek-pk-009 😁 thus whatever matched in one matches in the other

analog_programmer wrote on Today, 08:00:

Or I have to look for slow SRAM DIP-20 (cache) chips

umm sram chips need separate address bus, would requiring additional circuit bypassing chipset mem controller, latching address from cpu etc

solder two 30pin simm sockets, or just solder short wires to simms directly and plug into sockets, will probably work fine at 16MHz

rasz_pl wrote on Today, 11:54:

analog_programmer wrote on Today, 08:00:

I just don't want another useless "[Unknown] (Suntac 286)" article with my board's pictures to pop-up on TRW site, so I didn't care to provide any hi-res quality pictures in the Predator99's thread.

but you didnt provide those here either 😀 you are the only person able to spot those differences

I didn't published new picture here either, because I'm not proud of my DIY SMD-to-"full-can"-crystal-oscillator adapter. I had to do such thing, because I didn't manage to get trough-hole mount (DIP?) crystal of 32.000 MHz, but got much smaller one for surface mount.

rasz_pl wrote on Today, 11:54:

umm sram chips need separate address bus, would requiring additional circuit bypassing chipset mem controller, latching address from cpu etc

solder two 30pin simm sockets, or just solder short wires to simms directly and plug into sockets, will probably work fine at 16MHz

Interesting. I read somewhere on the i-net, that back in the times some people installed SRAM chips instead of DRAM for maximum performance on (8088/86 and V20/30) XT-motherboards without any modifications (except the software setting for PIT ch.1 refresh stop). I'll have to search for this info again.

But where exactly I have to solder those 30-pin SIMM sockets, since there are no trough-holes left for such things? 😁 This board is full of DIP sockets for DRAM chips - in general same layout as the Panatek PK-009 and the TRW-unknown one.