VOGONS


First post, by TheMobRules

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I've had this Biostar 486 motherboard for a while, as you see it is ISA only but has a couple of unpopulated VLB slots:

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By looking at some pictures in the web of this board (there are not many), I noticed that the versions that have VLB slots don't seem to have any noticeable difference with mine regarding what components are populated, so I guess none of them are needed for VLB support? Even the jumper for setting VLB wait states is there on my board.

So do you guys think it's worth a shot trying to scavenge some VLB slots from a dead board and transplant them into this one? Or maybe I'm missing some VLB specifics that would prevent this from working? A VLB board would be way more useful to me than an ISA only one!

Reply 1 of 10, by TheMobRules

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I hate to resurrect my own thread, but I can't find any information about this VLB-crippled version of the board.

So, I went ahead and transplated a VLB slot from a dead donor board, and gave it a try with a few different VLB cards. Nothing. With an ISA VGA it POSTs immediately, but with VLB not even a beep.

However, by looking at the jumper settings I noticed an undocumented "Factory configured - do not alter" jumper J01 which was open by default. So, I shorted it and lo and behold, I get the video BIOS display with a VLB card and memory count starts!

My hope was short lived since after the memory count the POST hangs at the "WAIT..." message. I can enter the BIOS and change settings, but it won't go beyond that point, and rebooting (either soft or with the button) causes a blank screen.

I tried messing with the other undocumented jumper (JP4) but no success.

Since I am unable to detect any differences in components/layout with the version of the board that has the VLB slots by looking at pictures on the web, I'm guessing my BIOS may also be crippled which is preventing correct behavior with a VLB card.

Are there any owners of this board in the forum who could dump the BIOS and share it with me?

Reply 2 of 10, by Horun

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I have two Biostar 1433/50 boards in stored in boxes, not sure of the suffix's, though think one is a 1433/50-UIV. Will look tomorrow and see if one is a AE version.

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. https://archive.org/details/@horun

Reply 3 of 10, by Horun

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TheMobRules wrote on 2020-01-19, 00:49:

Are there any owners of this board in the forum who could dump the BIOS and share it with me?

Ok found both Bioteq/Biostar boards, one is MB-1433/50 AEA-V VER.5. Has Award BIOS sticker # AA7481545. The other is MB-1433/50UIV REV. 1 and would not be similar to yours. Will boot up the AEA-V board and try to save the bios....

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Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. https://archive.org/details/@horun

Reply 4 of 10, by TheMobRules

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Thanks a lot Horun! I also have both the AEA-V and UIV variants of this board, and as you say they are quite different, the UIV is a newer design with a different chipset.

If you manage to dump the BIOS of your AEA-V VER. 5 I can give it a try, mine is VER. 2 but there doesn't seem to be many differences at component level.

Reply 5 of 10, by Horun

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Ok bad news. My old CT BIOS card only let me save a 32k byte file off the boards ROM, not sure if it is all there. Really need a newer eeprom card, might try a newer NIC and see if uniflash can pull the whole file off it's bootrom socket and then will compare the MD5's.

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. https://archive.org/details/@horun

Reply 7 of 10, by Horun

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Ok have 4 diff saved BIOS files. Included a TEXT as to what each is and how done. Suggest you use a FLASH EPROM (not a perma PROM). If one set does not work proper try the other.

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Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. https://archive.org/details/@horun

Reply 9 of 10, by TheMobRules

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It works!! The BIOS dumped with NSSI/ATROM did the trick! I still need to have the undocumented J01 jumper shorted in order for VLB cards to work, but other than that everything seems to work just fine! I'll populate the remaining slot and do some more extensive testing this weekend, but I haven't had issues so far.

Regarding the reasons it doesn't boot with the original BIOS, I dumped it and seems I was on the right track... after comparing it with the one dumped by Horun, I noticed a string in the BIOS that mentions the motherboard model: in Horun's BIOS it is appropriately MB-1433/50 AEA-V, but in mine it's MB-1433/50 AEA-P, which refers to an older, ISA only version of the board with different layout but with the same chipset. So, it would seem that Biostar just slapped this old ISA-only BIOS into this VLB-crippled motherboard.

Anyway, thanks again Horun for taking the time to dump the BIOS from your board!!

Reply 10 of 10, by evasive

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Horun wrote on 2020-01-19, 17:17:

Ok found both Bioteq/Biostar boards, one is MB-1433/50 AEA-V VER.5. Has Award BIOS sticker # AA7481545. The other is MB-1433/50UIV REV. 1 and would not be similar to yours. Will boot up the AEA-V board and try to save the bios....

Hi Horun,
Could you dump the UIV as well? Not just for the Ultimate Retro database but there's someone with a rev 3 board for which don't have a working bios atm, this might be close enough to do the trick.