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Problem running DebugZ on Multicomp CP/M

R

riwide

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Joined
Apr 22, 2019
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12
I have built a standard Cyclone II c version of Multicomp and having good fun with it (mostly using mc-2g-1024 build) and have identified one application which is incompatible but runs on other CP/M builds (e.g. RC2014 - tested on Z80 and Z280 flavours))

Debugz v1.2 from Microcode Consulting (https://www.microcodeconsulting.com/z80/debugz.htm) is regarded as one of the best debuggers under CP/M (Z80) and is the only program I have found so far that won't work properly on Multicomp. It would be good if someone could confirm that. I've tried it on CP/M 2.2 and CP/M 3, same error on both.

The symptoms I get are that the program loads and then runs in a loop displaying BP error (As shown below), but on other CP/M hardware systems (CP/M 2.2 and CP/M 3) it just loads and runs normally (j command will give full screen debugging)

DEBUGZ v1.2 (C) 1988,1989 MICROCode Consulting

Terminal: Digital VT-100

Free: 0100-C2D5
DebugZ: C2D6-E804
#
*Unknown BP at F738
--EFZ- A=02 B=0023 D=0006 H=F609 S=E5A5 P=F738 ADD A,B
#
*UNKNOWN BP AT F738
--EFZ- A=02 B=0023 D=0006 H=F609 S=E5A5 P=F738 ADD A,B
#
*UNKNOWN BP AT F738
--EFZ- A=02 B=0023 D=0006 H=F609 S=E5A5 P=F738 ADD A,B
#
*UNKNOWN BP AT F73A
--EFZ- A=02 B=0023 D=0006 H=F609 S=E5A5 P=F73A LD B,A
#


Note that debugz needs to be configured for the screen type with dbginst.com, after terminal type set by SETQTERM.COM, if one wishes to use full screen debugging. The above error was verified with virgin program from MICROCode, and after patching to different terminal type, so the error on Multicomp is unrelated to my patching.

I found that the dbginst program doesn't work for me so I had to use ddt to read debugz.com, then read qterm.dat (as previously configured through setqterm.com) at 0006 (which overlays it at 106), ctrl-c out of ddt, then SAVE 44 DEBUGZ.COM

Can anyone verify this problem with running debug on Multicomp CP/M?


Richard
 
I tried to download DebugZ from the microcodeconsulting.com website but it take me to a ERR403 page (Operation Forbidden). Do I need to contact someone to download the DebugZ software?
Bill
 
Strange - the web site works for me today and a few days ago before I submitted to this thread, however it did fail for me about a week ago when I wanted to get debugz from the official source rather than off the Obsolescence Guaranteed site. I've got your email address from correspondence re zz80rc-cf on rc2014 usenet so I'll email you a copy of doc and software
Richard
 
riwide said:
I have built a standard Cyclone II c version of Multicomp and having good fun with it (mostly using mc-2g-1024 build) and have identified one application which is incompatible but runs on other CP/M builds (e.g. RC2014 - tested on Z80 and Z280 flavours))

Debugz v1.2 from Microcode Consulting (https://www.microcodeconsulting.com/z80/debugz.htm) is regarded as one of the best debuggers under CP/M (Z80) and is the only program I have found so far that won't work properly on Multicomp. It would be good if someone could confirm that. I've tried it on CP/M 2.2 and CP/M 3, same error on both.

The symptoms I get are that the program loads and then runs in a loop displaying BP error (As shown below), but on other CP/M hardware systems (CP/M 2.2 and CP/M 3) it just loads and runs normally (j command will give full screen debugging)
Click to expand...

Have you tried changing the restart vector? You can do it with DBGINST.COM.

Plasmo said:
I tried to download DebugZ from the microcodeconsulting.com website but it take me to a ERR403 page (Operation Forbidden). Do I need to contact someone to download the DebugZ software?
Click to expand...

You need to have JavaScript enabled to download.
 
Doublepost because edit expired:

Looked at the BIOS source code. RST 7 (38H) is used for a timer interrupt, so you get constant unexpected breakpoints. Change the vector to 6.
 
Thank you for the suggestion. Looking at the code it seems to me that the cbios is setting up a RST 7 responder to act on a hw initiated timer interrupt, so changing to setup a responder on RST 6 won't help unless I can also adjust the hw interrupt generation, but I believe RST 7 is a special case and the hardware would not be able to cope with generating RST 6.
 
Thanks for the suggestion of using DBGINST alter the restart vector. I tried it, setting RST 6 rather than RST 7 and it did not improve the problem, it even seems worse.
 
I am convinced that the mc-2g-1024 build is broken. Superficially it appears to run cpm2, cpm3 dos+ etc but I cannot run debuggers properly. The cycloneiiz80 build with rom-mjs runs all my debuggers correctly (debugz, ddt, zsid, z8e etc) but the n8vem repository on pbworks is broken/missing and so I cannot find any sources for the monitor or cp/m builds. I wish to change the default baudrate on serial ports if I stay with cycloneiiz80/rom-mjs.

mc-2g-1024 does provide sources to the monitor and bios for cp/m builds, but for me the build is faulty. I have tried installing from Quartus II 32-bit v13.0.1 using author's provided (pof file) build state, and I have tried rebuilding project and re-install - the symptoms remain that the debuggers crashout or misbehave.

Can anyone confirm that their version of mc-2g-1024 works correctly, and provide a link to a good build?
Cheers
Richard
 
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