Date   : Thu, 11 Oct 1984201:17:00-MDT
From   : Mark Becker <Cent.Mbeck%MIT-OZ@Mit-Mc.ARPA>
Subject: 22RSX - Bug discovery(ies)

Hello Keith --

     Keith, after <CPM.22RSX>REMOVE.COM did nasty things to my test
disk, I disassembled it and found a couple of interesting things.

Woe to those with systems that have:

    (a) other than an LXI H,WMADDR / SHLD 0006 in the warmboot routine
       for initializing locations 5 and 6.  Both 22RSX and REMOVE look
       for the LXI H,d16 / SHLD 06 sequence.

    (b) the BIOS WMBOOT routine in ROM - the RSX installation will
       work okay until the next JMP 0 when locations 5, 6, and 7
       are re-loaded from the BIOS WMBOOT routine.

    (c) Lastly, the routine that searches for LXI H,d16 / SHLD 06
       ( hex 21 xx xx 22 06 ) doesn't check for the 00 after the 06.
       The demo software blew up on me as (I found out later) there
       is an LXI H,d16 / SHLD 06F3 in my system before the warmboot
       vector gets initialized and the software got 'confused'
       and modified the wrong data.

       The *REAL* gotcha is that both programs search for the
       LXI / SHLD sequence starting at **04, "**" being system size
       dependent.

Whew... enough bug tracing for this week...

Mark