GLABios for Laser XT/3

Last Updated or created 2023-08-05

In previous post :

I mentioned a 2 ROM setup because the 8086 is 16bits instead of 8.
So I was wondering that maybe a recompile was needed, or the data being split over two roms (odd/even)

The guy from GLABios was so kind to build me two interleaved roms.

So while working on a padded bench, I tested the ROMs.

Working outside .. on the padded bench

Back to the roms, it didn’t work!

But I missed a detail in the technical manual (the bold text)

In Turbo XT /2 and Turbo XT /3, there are two 28-pin sockets for ROM,
both of them are occupied by 2764 which stored the BIOS. The contents
of the two 2764 are identical.
One of them contribute the ODD Byte to the system and the other EVEN Byte. Together they support 16 Bit BIOS

I don’t know why this is how it works, but when I flashed two the same 28C64’s it worked!
(I also tought that is was strange that both original roms had the same markings.

It workes!

Only remarks/observations:

  • There was a longer wait time before the CF Card was detected/accessed
  • GLABios mentions 8088 in the splashscreen, but the machine is a 8086


GLABios was not updated for displaying 8086 yet.
Error 1701 was the (old spinning) harddisk not being connected.

Nice .. harddisk infomation like size, rom address and CHS

2 thoughts on “GLABios for Laser XT/3”

  1. That version was just the standard GLaBIOS XT build that does no 8086 detection (only V20 or not). I just sent that to you to test the interleaved ROMs and make sure that it even booted… before we get fancy. 🙂

    1. Super!
      Well we don’t need interleaved apparently.
      But I’m being stoked that is working.
      If you need other tests, let me know.

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