Viewing Issue Advanced Details
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
05985 Crash/Freeze Critical (emulator) Always Jul 11, 2015, 10:45 Apr 20, 2018, 06:16
Tester MetalliC View Status Public Platform
Assigned To Resolution Fixed OS
Status [?] Resolved Driver
Version 0.163 Fixed in Version Build
Summary 05985: Z80 CPU core can't handle many IX/IY (0xdd/0xfd) instruction prefixes in a row
Description code in provided example software do follwing -
fills big RAM area with 0xFD and jump there

as result I see in error log a lot of "Z80 ':maincpu' ill. opcode $fd $fd" messages and then emulator exits, silently, without printing any callstack messages.
I think stack overflow happens.
Steps To Reproduce - unpack provided floppy image to MAME folder
- run "mame pentagon -flop1 fuckemul.trd"
- select TR-DOS (cursor up, enter)
- RUN (r, enter)
shortly emulator silently closes for me, other user reported appcrash message
Additional Information
Flags
Regression Version
Affected Sets / Systems
Attached Files
zip file icon fuckemul.zip (1,710 bytes) Jul 11, 2015, 10:45 Uploaded by MetalliC
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Notes
6
User avatar
No.11867
Tafoid
Administrator
Jul 11, 2015, 17:56
edited on: Jul 11, 2015, 17:59
Do we have any confirmed way to run this on real hardware and have it be something that we can actually see operate correctly - are there any visual clues built into the program that will let us know it works or doesn't other than exception crashing?

That said, I do get an exception, but no stack:
Exception at EIP=0000000002CC2966 (z80_device::illegal_1()+0x00a6): STACK OVERFLOW
User avatar
No.14938
Robbbert
Developer
Apr 10, 2018, 06:56
edited on: Apr 10, 2018, 07:00
This doesn't seem to be an issue any more.

No crash for me.

Also, I tried in super80m setting 32k of ram to FD and running it - no crash.

To test in super80m start it and do the following steps: (press enter at the end of each line)
F 0 7FFF FD
E 8001
(this gives a new prompt) type in C3 4 C0 then a period.
G0

You'll get a prompt on a new line, indicating success.
User avatar
No.14957
Robbbert
Developer
Apr 18, 2018, 04:30
No response, so let's close it.

Don't know who fixed it, or when.
User avatar
No.14962
Tafoid
Administrator
Apr 18, 2018, 19:44
Please do not assign current GIT as the "fixed" when you are not sure when something is fixed, just leave blank and resolve.
User avatar
No.14968
M.A.S.H.
Senior Tester
Apr 19, 2018, 23:22
I don't think this bug was fixed! I still get the error messages
[:maincpu] Z80 ill. opcode $fd $fd...
Using mame pentagon -flop1 fuckemul.trd -log
User avatar
No.14970
Robbbert
Developer
Apr 20, 2018, 06:16
The bug report was because it caused an unexpected exit, which has been fixed. The log message can be ignored.