Date   : Sat, 19 Feb 1983 00:13:00 EST
From   : John Paul McNamee <JDOS@mit-ai.arpa>
Subject: Re: TRS-80 Model II boot ROM

The ROM reads in track 0 sectors 1 to 26 into memory starting
at 0E00H. The track is in standard IBM single density. The
way the ROM checks for a "Radio Shack Operating System" being
on the disk is to check for the word "BOOT" at 1000H and
"DIAG" at 1400H. If these two words are present at these
locations the ROM assumes the boot track is ok. After loading
the track into memory the ROM will call 1404H (to do power on
diagnostics) and then jump to 1004H (to boot the rest of the
system). Disassembly of the ROM is easy. I have listings of
boot ROMs for Models II, 12, and 16 and a program to make it
easy to get a copy of the ROM on disk. If interested in this
program or a copy of the listings, let me know.

                       John McNamee