Invalid opcode for some ROMs

[shoce]

First of all thanks for this brilliant emulator.

Some NES ROMs doesn't work with the Fergulator due to "Invalid opcode" error. I was downloading a lot of my favorite games from Internet and most of them work like a charm. Though some don't work while they are declared to be NES ROMs.

Micro Machines ROM doesn't work:
-----------------
ROM:
PRG-ROM banks: 16
CHR-ROM banks: 0
Mirroring: Vertical
Mapper: 0x2 -> UNROM
-----------------
2013/01/11 14:34:41 Invalid opcode at 0xBFA8: 0x7

Can be downloaded from:
http://coolrom.com/roms/nes/798/Micro_Machines.php
http://romhustler.net/rom/nes/micro-machines-1

May be they are really for SNES, I don't know, please comment.

[scottferg]

Micro Machines has some pretty unique hacks in how it was written, and as a
result it's one of the games that's great for exposing inaccuracy in
emulators. Other great ones are Rad Racer, Super Mario 3 and Battletoads. I
never tried out MM since I never played it but I'll start using it for
debugging.

Getting an Invalid opcode typically points to the memory mapper working
incorrectly (an operand gets loaded into the CPU instead of an
instruction). UNROM is really simple so maybe it's how I'm initializing
PRG. Not totally sure, but I'll take a look. Thanks for letting me know!
On Jan 11, 2013 4:46 AM, "Ruslan Khusnullin" notifications@github.com
wrote:

First of all thanks for this brilliant emulator.

Some NES ROMs doesn't work with the Fergulator due to "Invalid opcode"
error. I was downloading a lot of my favorite games from Internet and most
of them work like a charm. Though some don't work while they are declared
to be NES ROMs.

Micro Machines ROM doesn't work:

ROM:
PRG-ROM banks: 16
CHR-ROM banks: 0
Mirroring: Vertical

Mapper: 0x2 -> UNROM

2013/01/11 14:34:41 Invalid opcode at 0xBFA8: 0x7

Can be downloaded from:
http://coolrom.com/roms/nes/798/Micro_Machines.php
http://romhustler.net/rom/nes/micro-machines-1

May be they are really for SNES, I don't know, please comment.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/4.

[shoce]

It would be great to have Battle Toads working too! I loved the Toads. :)

On Fri, Jan 11, 2013 at 6:54 PM, Scott Ferguson notifications@github.comwrote:

Micro Machines has some pretty unique hacks in how it was written, and as
a
result it's one of the games that's great for exposing inaccuracy in
emulators. Other great ones are Rad Racer, Super Mario 3 and Battletoads.
I
never tried out MM since I never played it but I'll start using it for
debugging.

Getting an Invalid opcode typically points to the memory mapper working
incorrectly (an operand gets loaded into the CPU instead of an
instruction). UNROM is really simple so maybe it's how I'm initializing
PRG. Not totally sure, but I'll take a look. Thanks for letting me know!
On Jan 11, 2013 4:46 AM, "Ruslan Khusnullin" notifications@github.com
wrote:

First of all thanks for this brilliant emulator.

Some NES ROMs doesn't work with the Fergulator due to "Invalid opcode"
error. I was downloading a lot of my favorite games from Internet and
most
of them work like a charm. Though some don't work while they are
declared
to be NES ROMs.

Micro Machines ROM doesn't work:

ROM:
PRG-ROM banks: 16
CHR-ROM banks: 0
Mirroring: Vertical

Mapper: 0x2 -> UNROM

2013/01/11 14:34:41 Invalid opcode at 0xBFA8: 0x7

Can be downloaded from:
http://coolrom.com/roms/nes/798/Micro_Machines.php
http://romhustler.net/rom/nes/micro-machines-1

May be they are really for SNES, I don't know, please comment.

—
Reply to this email directly or view it on GitHub<
https://github.com/scottferg/Fergulator/issues/4>.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/4#issuecomment-12147219.

[scottferg]

Battletoads works, so does Battletoads and Double Dragon. There's some graphical weirdness at times but it's very playable.