Viewing Issue Advanced Details
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
08071 Graphics Major Always Sep 2, 2021, 04:11 Sep 4, 2021, 23:09
Tester Dullaron View Status Public Platform MAME (Official Binary)
Assigned To Resolution Open OS Windows 10 (64-bit)
Status [?] Confirmed Driver
Version 0.235 Fixed in Version Build 64-bit
Fixed in Git Commit Github Pull Request #
Summary 08071: czeroize: [possible] Graphics start messing up at number 50.
Description Here is a video that I made showing the graphics issue on the countdown. I had to start the recording before it get to 50.

I already know there is no dump of the Is this the issue? Should be flag yellow?
Steps To Reproduce
Additional Information
Github Commit
Flags Possible
Regression Version
Affected Sets / Systems czeroize
Attached Files
There are no relationship linked to this issue.
User avatar
Sep 2, 2021, 05:11
The graphics malfunction you mentioned is documented in the MAMEINFO.dat file and is expected. Whether or not it is correct behaviour from the original cassette load on original hardware, I'm not 100% sure.

- The tape loading counter starts at 142 and the graphics messed up at 50, because some data are loaded into the character/sprite generator RAM area.

The .pro file is the protection dongle which has not been dumped. There is simulation in place at this time until such a dongle is found.
As documented in the src\mame\machine\decocass.cpp file:
* FIXME: remove if the original ROM is available.
* The Zeroize 6502 code at 0x3707 issues LODCTRS with 0x8a,
* and expects to read 0x18 from 0x08a0 ff. within 7 bytes
* and 0xf7 from 0x8a1 (which 0xd is subtracted from presumably in order
* to form a NOP of 0xea).
* This hack seems to be sufficient to get around
* the missing dongle ROM contents and play the game.
User avatar
Sep 2, 2021, 05:37
ok I will mark it red flag in my notes.