Path: utzoo!attcan!uunet!ncrlnk!ncr-sd!hp-sdd!ucsdhub!sdcsvax!ucsd!ames!mailrus!cwjcc!tut.cis.ohio-state.edu!osu-cis!att!ihlpa!wolfordj
From: wolfordj@ihlpa.ATT.COM (452is-Wolford)
Newsgroups: comp.sys.ibm.pc
Subject: Help needed adding drive types to PHOENIX BIOS
Keywords: ibmpc phoenix bios
Message-ID: <11416@ihlpa.ATT.COM>
Date: 25 Jan 89 15:35:30 GMT
Organization: AT&T Bell Laboratories - Naperville, Illinois
Lines: 30

I am trying to add/replace a drive type in my PHONENIX BIOS v3.10 00.

I found where the drive table is and know the numbers that I want
to put in the table, but after reading the rom, adding the numbers
and "burning" a new set of rom, I get a rom check sum beep error
code on boot and the machine hangs.

Well that is no wonder since I did change the contents of the rom code
and did not change the check sum, BUT:

I can not seem to find where and how the check sum is computed, and/or checked.

Any help would be greatful.

BTW: This is a problem because the BIOS looks at the drive parameters
instead of the drive description sector on the hard disk.  My machine with
AWARD BIOS does this just find.  This same type of problem show's up
when I want to read a 720K 5 1/4" (You know the 80TK DS/DD diskette).
Seems the bios think that since it has 80 tracks that it must be a 1.2MB
disk.

Jeff Wolford
att!iwsag!jww
att!ihlpa!wolfordj

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