Identification two reverseable top 286 class motherboards.

[Robin4]

The one with the black sockets it the newer revision board. ( i also could be wrong)

In the corner it says PAT.

Iam guessing max mem on this boards would be 1MB.. Because it only should take 41256 Kbit chips..

Special about these boards is, they are for reverseable AT cases.

Logo on the board seems familiar to me, when i think back to the past.
But i really cant remember which company did used that logo which is stamped om the PCB.

 

[eiffelben]

I have the same mobo (the PAT-7.2A variant) and it seems to come from an Arche Rival 286-12. In my case it was an easy fix with the corrosion and it's genereally quite easy to work with. I'm going to post some jumper descriptions for it when I'm finished with them. So far I've found the memory config, speaker, keyboard lock, reset switch and some jumpers that seems related to the ROM chip sizes.

Please see this thread:

https://forum.vcfed.org/index.php?threads/arche-rival-286-computer-motherboard-identification-please.1241540/

 

[Robin4]

I bought 3 other ones from the same seller. Also seen to sort out on the 5 volt line. (5volt to ground)

One had the bios roms on it.. But iam not sure if these where the original or not.

 

[Robin4]

I already found out that this moterboard seems to be a MYCOMP motherboard,
I have wrote something on the vogons forum i will post here.

I can 100% comfirm that logo is from MYCOMP..
Got a HDS MFM 8 bit controller today in the lot.
Red out the onboard bios.
Had the same logo printed out in the PCB.
It says really MYCOMP in that bios.

I dont know the history of that company.. But it seems that is was there in the early 80s.. Like 1984 / 1986)
Maybe some other company took MYCOMP over and got a name rebranding to TMC ?
So my question seems be answered.



Watch that logo on the left upper corner.



This information came out of that EPROM on that MFM controller card.

 

[Robin4]

If someone has the same MFM card on the picture, please let me know.
I got that card yesterday in a bigger lot of parts..
Seems the former owner was a hobbyist too.
Only made a mess of the card and on some other parts he had (he passed away)
Like to see if i can get the card back to normal and working again.
The bios eprom seems to be fine.
Iam really looking after for a nice clear picture to see the original components on it.
So i could try and see to get it back to original shape.

 

[evasive]

TMC = Taiwan Mycomp Company
also known under Mynix and Megastar
Board is now listed under the proper identifier:

TMC/MyComp/MyNix/Megastar PAT-7.2/Y-7.2

TMC/MyComp/MyNix/Megastar PAT-7.2/Y-7.2 is a motherboard based on the Chips & Technologies CS8220 (PC/AT compatible CHIPSet) chipset. Get specs, BIOS, documentation and more!

theretroweb.com

If possible, we would like to have front and back pictures of your board because it is logo'd.

 

[Robin4]

Will make tomorrow.

 

[Robin4]

This is the normal PAT without version 7.2
Sorry i dont have a good camera, only a cell phone.






This one is a PAT-7.2A

I got still 2 other boards of these. All where without the bios roms.

Revision changes looks like they used new style resistor array packs above the memory.
Think the white ones where the old style, and probably discontinued later on.. So thats why they change it to a different part.

 

[Robin4]

Extra note. I see on the retroweb that FSB is 12.5Mhz.

My boards using a 20.000Mhz crystal.. So probably these where for 10 Mhz cpus too.

 

[eiffelben]

Extra note. I see on the retroweb that FSB is 12.5Mhz.

My boards using a 20.000Mhz crystal.. So probably these where for 10 Mhz cpus too.

My board has a 24 Mhz osc but judging by the markings on some ICs the chipset was rated for 12.5 MHz. That's probably where that number came from.