VOGONS

Search

Common searches

Searching for some info on OCTEK HIPPO II 486 mainboard

Topic actions

First post, by tabaglio

Posted on 
User metadata
Rank Newbie
Rank
Newbie

Greetings!
I recently recovered a box of scrapped boards, some in good shape, some in various state of disassembly. Between these, I found this AT motherboard.

On this HIPPO II 486 rev 2.1 board some components were removed, but given that it is in a very good general shape (and it came with a processor too!) I'd like to give it a chance at life before recovering the components. I'm sure I have better 486 mainboards, but I really hate disassembling things when they still have a chance to work.

PXL_20210916_085520440.jpg
Filename
PXL_20210916_085520440.jpg
File size
809.7 KiB
Views
557 views
File license
Public domain

This board uses an OPTi 82C493/C206/C392 chipset.

What was removed is the following:
- some generic 74' logic chips (already replaced)
- the BIOS chip
- The oscillator at Y2, see photo, bottom of the board. I already put a socket in there so I can try different ones.

The board looks very similar to its successor, the HIPPO III that is documented at http://www.win3x.org/uh19/motherboards/4028, so I guess I can more or less look at that for the jumper settings...

But what I really need is the following:

  • Does anyone have this board and can check the oscillator frequency for me? I couldn't find a photo online, and boards with this chipset come with 33/50/66Mhz oscillators...
  • I could try various bios images of OPTi boards linked at win3x.org, but if someone has a dump for this one, it would be a better option: one less unknown to worry about.

I know it'll be very hard to recover everything necessary to get this board up and running, but hey, at least need to try!

Reply 1 of 8, by tabaglio

Posted on 
User metadata
Rank Newbie
Rank
Newbie

In the meantime, it seems the manual is still available here: https://www.elhvb.com/mobokive/Archive/Octek/ … 20II/index.html

[edit]
I was able to get the board to boot using the bios at this page: http://www.win3x.org/uh19/motherboards/1499

[edit 2]
Using a 40Mhz oscillator at Y2 for now. I actually suppose a 33Mhz was in there, but I don't have one around.
I also tried a 50Mhz and a 66Mhz one, but both caused the system not to boot.

Reply 2 of 8, by tabaglio

Posted on 
User metadata
Rank Newbie
Rank
Newbie

I think I've also been able to reverse (original was read protected) the PAL16L8 at U52, near the keyboard controller.
Attaching the JED file to burn to a GAL16V8. With this, my board boots fine like with the original,I did not do much more testing though (obviously the board does not work with the chip removed).

Attachments

  • Filename
    U52.zip
    File size
    607 Bytes
    Downloads
    26 downloads
    File comment
    Octek Hippo II reversed PAL16L8 at U52 (burn to GAL16V8)
    File license
    Public domain

Reply 5 of 8, by tabaglio

Posted on 
User metadata
Rank Newbie
Rank
Newbie
TheMobRules wrote on 2021-09-19, 18:44:

Nice job! Could you describe the process you followed to reverse that PAL?

Thanks, I developed my own tools for this job: https://github.com/DuPAL-PAL-DUmper/DuPAL_Analyzer

It's basically bruteforcing, followed by a step of manual massaging (mostly to simplify equations that use feedbacks as inputs). I wrote a small explanation here: https://github.com/DuPAL-PAL-DUmper/DuPAL_Ana … ocs/analysis.md.
It's crude, but it does the job for me 😀

Reply 6 of 8, by TheMobRules

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie
tabaglio wrote on 2021-09-20, 00:17:

Thanks, I developed my own tools for this job: https://github.com/DuPAL-PAL-DUmper/DuPAL_Analyzer

It's basically bruteforcing, followed by a step of manual massaging (mostly to simplify equations that use feedbacks as inputs). I wrote a small explanation here: https://github.com/DuPAL-PAL-DUmper/DuPAL_Ana … ocs/analysis.md.
It's crude, but it does the job for me 😀

Awesome! I have a PAL16L8 from a battery-damaged 386 board that I'm restoring (also near the KB controller), it's probably still working but the legs have been deeply affected by corrosion. I will try to fix that by re-tinning the legs but I wanted to try and reverse it just in case I kill it during the restoration process.

I will definitely be taking a look at your work, many thanks!

Reply 7 of 8, by tabaglio

Posted on 
User metadata
Rank Newbie
Rank
Newbie

Quick update: I tried various other BIOSes and found out this to work best so far: http://www.win3x.org/uh19/motherboards/1495

The turbo button works, and I also got a performance boost running normally. I suspect cache was not correctly enabled previously.

Go to top of page Go to top of page
Back to General Old Hardware
Close window
Close window