Date   : Sat, 08 Sep 1990 20:29:00 CDT
From   : LANCE TAGLIAPIETRA <TAGLANCE@UWPLATT.EDU>
Subject: Sysgen and installing Z80CCP

Hello All,
 
Since I made my plea for help about SYSGEN on the TRS-80 Model 4, I
have discovered a few more things as I attempt to install Z80CCP.
 
I verified that DDT is loading the Z80CCP overlay correctly over the
old CCP which I placed in memory with SYSGEN. I am using the correct
offset.
 
SYSGEN seems to be checking a few bytes in the image, and will lock
the system up if those bytes do not agree with the cp/m ccp. I found
these by using ddt to fill areas of the cp/m ccp with 00H untill
SYSTEN would lock up (requiring reset) when looking at the memory
image of cp/m. I used divide-and-conquer until I located 5 bytes in
the ccp that cannot be changed to 0: (in the sysgen image) 0d28:10,
0d29:16, 0d2a:04, 0d2c:bf 0d2d:08. Other times sysgen will say I
a bad image and abort when I try to use the modified image.
 
Using DU-V85 (a disk utility available on simtel20) I found the
sectors on my system disk where the ccp is located. I have also worked
out the correct offset for DDT so that I can overlay the Z80CCP
correctly over the old version as Yanked off my system disk with DU
(no offset for SYSGEN).  What I need is a routine that will take
sectors from a file and write them to disk. DU will talk sectors
Yanked into memory and put them into a file, but not the reverse.
Does anyone have any suggestions?
 
Thanks again for your reply.  It is nice to know that at least someone
read my posting.
 
Lance Tagliapietra  taglance@uwplatt.edu