I just got a board very similar to your 386/33-64k. It's made by CTI computers. It's not in TH99, but has a very similar layout to yours. Mine has AMI BIOS and does not accept 4MB SIMMs. The BIOS is very old. It has a 1990 date code, and has very limited options. I attempted to update to the 1991 core by swapping in another board's BIOS, but the system failed to POST. This is the first time I've ever done a same chipset BIOS swap that didn't work at all.
Strangely enough, my cache upgrade kind of worked out okay. My board has 24-pin cache sockets and can take either 16kx4 (22 pin) or 64kx4 (24 pin) type modules. I do not have the jumper settings for my board, but upgrading from 64k to 256k without setting any jumpers gave me 128k in software cache tests. I guess as your Asus only has 22 pin sockets a 256kb upgrade is out of the question unless they made 64kx4 chips in that arrangement.

Hi U all,

i am reading this post lately but want to buid a retro game machine ;
i think i have the answer about the difference between both ASUS mobo : the chipset , Sis allowing >64ko cash MEM , and certainly not the fabulous PCchip one.

i let you agree with both pics ; otherwise , both mobo are quit identical.

Best regards

and the other.....

Scored one of these boards today, it came out of a rusty portable PC and had a lot of muck and dust (see the CPU).
Ordered some new caps as I can see a few are damaged, hopefully she POSTS after a recap and tidy up 😀

I am going to do a thread on the luggable but if anyones interested its the Scantech LCD-386 or variant.
Really interesting case as you can use this cirrus logic vga card to display internal mono or external VGA

I have added tikoellner's image here http://www.win3x.org/uh19/motherboard/show/792

Since you all have that board, anyone would like to upload their BIOS please ? It seems one of you have a AMI bios for that board too even though most seem to have the award bios !

The MR-BIOS for SiS Rabbit chipset was found. I tried it on my CTI 386 board, but it didn't POST at all. You might want to give it a shot in your Asus board though.

Anyone had any experience putting in one of the cyrix DLC 486 chips in here?

@deksor - I will upload mine as soon as I get the board to POST 😀 it's in surgery right now

Hi guys, I just got the very same Asus 386/33-64k mainboard. It's seems to be dead. Someone already soldered here and there and an IC was missing. I got the IC back in place, but the board still seems to be dead so far. My suspicion was that the BIOS is not the original one. Since you can clearly see "386 BIOS HI" on it. I thought HI? And where is LOW? This didn't seem right to me, so I searched the net and stumbled over this thread. And what do I see?! @4xtx posted a picture with the BIOS label "386 BIOS HI" as well. Now I'm quite confused. It can be barely a co-accident, that we both have wrong BIOS Chips with the same label. So I guess "386 BIOS HI" must be just a misleading label? Does one of you guys have this mainboard POSTing? And could you please put your ROM image here, so we can upload it to the UH19 project? That would be great!

scorp wrote on 2021-02-28, 13:28:

@4xtx posted a picture with the BIOS label "386 BIOS HI" as well. Now I'm quite confused. It can be barely a co-accident, that we both have wrong BIOS Chips with the same label. So I guess "386 BIOS HI" must be just a misleading label? Does one of you guys have this mainboard POSTing? And could you please put your ROM image here, so we can upload it to the UH19 project? That would be grate!

Will do 😀 I feel like I have many submissions overdue on that project.

With regards to the BIOS; it is very scaled back and only has boot priority and configuration.
It also does this weird thing where the font colors seem to persist once DOS starts until you CLS
While I don't mind the blue background it would be nice to not have it there as a default.

Also just so you are aware - my board came out of a portable PC that identifies as "Scantech LCD-386"
It is unique in that it accepts a standard AT board and came with ISA VGA with some sort of LVDS driver on it (scorp - you had a similar one on your YT which I commented on) I had to replace most of the tantalums but otherwise the board was OK (External battery!)
Unfortunately I cannot restore that unit as it had a very high voltage board inside the (extremely compact) PSU which has exploded due to previous damage.
That board drives the LCD interface which is really a poor display anyway..

Here's a sample link from someone else looking to the unit [https://linustechtips.com/topic/952826-old-pc … ed-dos-to-work/]