NintendoAge http://nintendoage.com/forum/ -Sqooner does the AVS handle unofficial opcodes the same as the NES? http://nintendoage.com/forum/messageview.cfm?catid=106&threadid=173468 2018-02-17T03:31:59 -05.00 Lincoln 6   ]]> does the AVS handle unofficial opcodes the same as the NES? http://nintendoage.com/forum/messageview.cfm?catid=106&threadid=173468 2018-02-12T01:43:34 -05.00 Lincoln 6 Originally posted by: bunnyboy
 
Originally posted by: Lincoln

Gaau Hok Gwong Cheung (Ch) uses XAA ($8B), an immediate instruction. The game malfunctions after selecting Left from the main menu if that instruction is not emulated.
Is there any place to get this cart or a ROM that runs on flash carts / repro boards / common emulators?  Only found the unif version which has zero mapper info.

 
the first rom i found is the unif one with mapper UNL-43272. it runs ok in fceux 2.2.3 although i couldn't say how accurate it is.  ]]> does the AVS handle unofficial opcodes the same as the NES? http://nintendoage.com/forum/messageview.cfm?catid=106&threadid=173468 2018-02-11T22:08:14 -05.00 Lincoln 6 Originally posted by: Lincoln

Gaau Hok Gwong Cheung (Ch) uses XAA ($8B), an immediate instruction. The game malfunctions after selecting Left from the main menu if that instruction is not emulated. Is there any place to get this cart or a ROM that runs on flash carts / repro boards / common emulators?  Only found the unif version which has zero mapper info.

  ]]> does the AVS handle unofficial opcodes the same as the NES? http://nintendoage.com/forum/messageview.cfm?catid=106&threadid=173468 2017-05-03T18:54:08 -05.00 Lincoln 6
The use of unofficial opcodes is rare in NES games. It appears to occur mostly in late or unlicensed titles:
Puzznic (all regions) (US release November 1990) uses $89, which is a 2-byte NOP on 6502.
F-117A Stealth Fighter and Infiltrator also use $89.
Beauty and the Beast (E) (1994) uses a different 2-byte NOP ($80).[1]
Dynowarz uses 1-byte NOPs $DA and $FA on the first level when your dino throws his fist.
Gaau Hok Gwong Cheung (Ch) uses XAA ($8B), an immediate instruction. The game malfunctions after selecting Left from the main menu if that instruction is not emulated.
Super Cars (U) (February 1991) uses LAX ($B3)
Disney's Aladdin (E) (December 1994) uses SLO ($07). This is Virgin's port of the Game Boy game, itself a port of the Genesis game, not any of the pirate originals.
As hobbyists became aware of what these instructions could do, homebrew games started to use them:
The MUSE music engine, used in Driar and STREEMERZ: Super Strength Emergency Squad Zeta, uses the unofficial opcodes $8F (SAX), $B3 (LAX), and $CB (AXS) [2]
Attribute Zone uses $0B (ANC), $2F (RLA), $4B (ALR), $A7 (LAX), $B3 (LAX), $CB (AXS), $D3 (DCP), $DB (DCP).
The port of Zork to the Famicom uses a few unofficial opcodes.

Super Cars uses the instruction I was wondering about (but a different version). I suppose that would be a reasonably good test. ]]> does the AVS handle unofficial opcodes the same as the NES? http://nintendoage.com/forum/messageview.cfm?catid=106&threadid=173468 2017-05-03T14:33:12 -05.00 Lincoln 6 does the AVS handle unofficial opcodes the same as the NES? http://nintendoage.com/forum/messageview.cfm?catid=106&threadid=173468 2017-05-02T16:58:28 -05.00 Lincoln 6