Post AZt0Sn5cWAVs39khN2 by hakfoo@mstdn.party
 (DIR) More posts by hakfoo@mstdn.party
 (DIR) Post #AZt0Sm8m2xRR6eDheC by xenenic@bitbang.social
       2023-09-16T22:05:13Z
       
       0 likes, 0 repeats
       
       Ok #retrocomputing and #vintagecomputing I need some assistance modifying the 386SX #BIOS for my "Magnavox Professional Metalis SX-20" as adding a drive overlay causes a checksum failure.The BIOS is hard locked to NONE/40/60/80MB HDD options and modifying what appears to be the drive table via MODBIN has failed me thus far.Any recommendations for disabling the checksum?"AWARD 386 BIOS V 3.04d 12/20/91"I'm looking at the dump via "objdump -D -b binary -mi386 -Maddr16,data16 mvox.bin".
       
 (DIR) Post #AZt0Sn5cWAVs39khN2 by hakfoo@mstdn.party
       2023-09-18T06:00:18Z
       
       0 likes, 0 repeats
       
       @xenenic Is there any way to install an option ROM and use the XT-IDE Universal BIOS?  Or even set it as "no hard disc", boot from floppy, and use something like https://github.com/rvalles/optromloader to load it?I have a 386SX Magnavox desktop, and its BIOS will let you enter a geometry up to 8Gb(!) but the onboard BIOS did not know what to do with a SD-IDE adapter with a large card in it.  XUB solved it, although the original BIOS reports an IDE error before booting.
       
 (DIR) Post #AZt0So4wq9ZN7MRfxg by xenenic@bitbang.social
       2023-09-18T06:07:13Z
       
       1 likes, 2 repeats
       
       @hakfoo I'm actually messing with the BIOS atm and was thinking of trying to use XT-IDE if I can get the JMPs figured out as another possible solution to the hard coded disk geometry. BIOS screenshot of the 16MHz board for reference.