CAESAR Logo

Catalogue of Arcade Emulation Software - the Absolute Reference

Valid XHTML 1.0! Valid CSS!

X-Arcade

X-Arcade

Large CAESAR Logo

mexico86.c

0.36b9 [Ernesto Corvi, Acho A. Tang]

0.35b7 [Ernesto Corvi]


NOTES:

- 4 players mode is not emulated. THis involves some shared RAM and a subboard. There is additional code for a third Z80 in the bootleg version, I don't know if it's related or if its just a replacement for the 68705.

- kicknrun does a PS4 STOP ERROR short after boot, but works afterwards. PS4 is the mcu.

- Kiki Kaikai suffers from random lock-up's. It happens when the sound CPU misses CTS from YM2203. The processor will loop infinitely and the main CPU will in turn wait forever. It's difficult to meet the required level of synchronization. THis is kludged by filtering the 2203's busy signal.

- KiKi KaiKai uses a custom 68701 MCU which isn't dumped. The bootleg Knight Boy replaces it with a 68705. The bootleg is NOT 100% equivalent to the original (a situation similar to Bubble Bobble): collision detection is imperfect, the player can't be killed by some enemies. I think the bootleggers put the custom mcu in a test rig, examined its bus activity and replicated the behaviour inaccurately because they coudln't figure it all out. Indeed, the 68705 code reads all the memory locations related to the missing collision detection, but does nothing with them.

- In the KiKi KaiKai MCU simulation, I don't bother supporting the coinage dip switch settings. Therefore, it's hardwired to be 1 coin / 1 credit.


NOTES (Acho A. Tang):

- Part of Kiki's code runs straight across banked ROM boundaries which MAME's current memory model doesn't seem to handle very well. The result is garbage being executed and thus the game crashes. This can be avoided by preloading bank zero into its default location.

- Kiki Kaikai also suffers from random lock-up's. It happens when the sound CPU misses CTS from YM2203. The processor will loop infinitely and the main CPU will in turn wait forever. It's difficult to meet the required level of synchronization but we can filter the 2205's busy signal.

- Collision is not working on some sprites and the exact reason is unknown.

- Modified VIDEO_UPDATE. The orignal is a Mexico86 duplicate which produces graphics artifacts especially beyond stage 3.

- Rearranged DIP settings according to the Japanese manual.


Bugs:

- Error messages in vidhrdw/mexico.c: WRITE_HANDLER( mexico86_bankswitch_w ): kicknrun, kikikai and mexico86. messages056ora stephh / almightyjustin


WIP:

- 2nd November 1999: Nicola added Kiki Kaikai to the Mexico 86 driver, but only attract mode works.

- 1st November 1999: Nicola Salmoria and Ernesto Corvi have fixed Mexico 86 and Kick & Run.

- 0.35b7: Added mexico86.c driver.