PDA

View Full Version : Looking BIOS for Video Seven VGA-16 (chip L1A4199) ISA video-card



Tronix
April 16th, 2017, 12:22 PM
Hello,

I'm looking for a BIOS with this video card:

37861

This video-card is similar to this one: http://www.vgamuseum.info/index.php/cards/item/498-video-seven-l1a4199 and this card: http://www.minuszerodegrees.net/rom/rom.htm (VGA-16E (http://www.minuszerodegrees.net/rom/photo/Video%20Seven%20VGA%2016E.jpg))
Both links contain a BIOS firmware (v1.09 and v1.14). But there is a question - the photos show that there are two EPROM chips on the card - first 27C128 (marked ODD) and second 27C256 (marked FULL). BIOS v1.14 have size 32Kb. BIOS v1.09 have size 24Kb. What was the purpose of the chip 27c128 when the full BIOS image climbs in 27c256? Can anyone who has a similar card read the both EPROM data on the programmer?

Thank you.

modem7
April 16th, 2017, 05:29 PM
I have added ROM images for my variation of the VGA-16 to [here (http://minuszerodegrees.net/rom/rom.htm)].
It was something that I had been meaning to do for a while.

kgober
April 16th, 2017, 07:50 PM
I am guessing that the FULL EPROM contained the full BIOS in 8-bit bytes. If you plugged the card into an 8-bit slot this would be the only EPROM that gets used (because in an 8-bit slot, all accesses are 8 bits).

But if you plugged the card into a 16-bit slot, the system would expect to be able to read the BIOS 16 bits at a time, which meant you needed another ROM to serve the upper 8 bits (the ODD bytes). So in a 16-bit slot the ODD EPROM serves the odd bytes, while the even bytes come from the FULL EPROM.

-ken