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ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
06779 Crash/Freeze Critical (emulator) Always Nov 28, 2017, 22:35 Nov 29, 2017, 11:07
Tester MrGW View Status Public Platform MAME (Self-compiled)
Assigned To Duke Resolution Fixed OS Linux (64-bit)
Status [?] Resolved Driver
Version 0.191 Fixed in Version 0.193 Build 64-bit
Fixed in Git Commit Github Pull Request #
Summary MESS-specific 06779: Mounting Zenix Floppy Disk crashes MAME with floating point exception error
Description When you try to mount the floppy disk based game "Zenix" using MAME's built-in UI or the command line, it crashes MAME.

Here's the command line I used:

~/.mame $ mame coco3 -flop1 ZENIX.DSK
Floating point exception
Steps To Reproduce Here's the command line I used:

~/.mame $ mame coco3 -flop1 ZENIX.DSK
Floating point exception

... or use MAME's UI to browse for the ZENIX.DSK file and mount it on the first floppy drive.
Additional Information I've tested this same disk image on a real Coco 3 using the CoCoSDC storage device. No issues. I've also tested the same disk image on the VCC 2.01b emulator (for Windows). No issues.

I have a self-compiled ARM build of MAME 0.191 (32bit) and it crashes as well.

I've attached the disk image for you to test.
Github Commit
Regression Version
Affected Sets / Systems
Attached Files
zip file icon (46,683 bytes) Nov 28, 2017, 22:35 Uploaded by MrGW
Zenix Game Disk image for the Coco 3
png file icon zenix.png (32,732 bytes) Nov 29, 2017, 00:36 Uploaded by MrGW
There are no relationship linked to this issue.
User avatar
Nov 28, 2017, 23:46
This is a JVC formatted disc, apparently. Are we positive the 5 byte header is correct? MAME tends to be pretty exacting when it comes to headers to specific formats and other emulators may simply treat a floppy as a memory dump rather than an specific type of image.

I can confirm it doesn't mount without an exception happening, but I'm not sure if it is a shortcoming of the emulation or an issue with the header.
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Senior Tester
Nov 28, 2017, 23:56
Exception at EIP=01ffe334 (jvc_format::parse_header(io_generic*, int&, ...)+0x01e4): INTEGER DIVIDE BY ZERO
User avatar
Nov 29, 2017, 00:37
Hi Tafoid and Robbbert. I did a BACKUP of this disk to a new disk image I created (in Disk Extended Color Basic in VCC). The backup copy caused the same crash in MAME.

I created a new blank disk image again (using toolshed) and mounted the ZENIX.DSK as DRIVE 0 and the blank disk in DRIVE 1 in VCC. I did a copy of the 2 files on the disk 0 to disk 1.

MAME can mount the new disk and I see the 2 files. When I try to LOADM the game, I get to the following screen (attached). It looks like the ZENIX.DSK image has some sort of copy protection on it (which is probably correct). I got that disk image from the TRS-80 Color Computer Archive.
User avatar
Nov 29, 2017, 09:23
Fixed in commit 5676444d8cf9da4b27ceba2efd0a2d82a343cc57.
User avatar
Nov 29, 2017, 11:07
Thanks, Duke!