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author arbee <rb6502@users.noreply.github.com>2017-05-23 20:47:50 -0400
committer arbee <rb6502@users.noreply.github.com>2017-05-23 20:47:50 -0400
commit38af01ff636e3eb4e63f1ac257972b87cc2b79cb (patch)
tree7888aff908a649f31cc8ae6e36c4bf990cf3b5c2
parent50b20ddf23ea1b959732f6ad65d54f3949f9f068 (diff)
xavix: Notes on what the CPU should be. (nw)
-rw-r--r--src/mame/drivers/xavix.cpp23
1 files changed, 20 insertions, 3 deletions
diff --git a/src/mame/drivers/xavix.cpp b/src/mame/drivers/xavix.cpp
index 1f04500145d..c6e618220f1 100644
--- a/src/mame/drivers/xavix.cpp
+++ b/src/mame/drivers/xavix.cpp
@@ -4,11 +4,28 @@
Skeleton driver for XaviX TV PNP console and childs (Let's! Play TV Classic)
- CPU is M6502 derivative, almost likely to be a G65816
+ CPU is an M6502 derivative where opcode 0x22 has 3 bytes of operands.
+ Definitely not: 65C816 or Mitsu M740.
+
+ Code at F34F is thus:
+
+ F34F: STA $6200,X
+ F352: INX
+ F353: BNE $F34F
+ F355: UNK 12 FA 80
+ F359: UNK 12 A8 80
+ F35D: UNK 12 1B 80
+ F361: SEC
+ F362: LDA #$CD
+ F364: SBC #$CA
+
+ later on
+
+ F3C9: UNK 00 E4 C4
TODO:
- - understand how to map ROM at 0x800000-0x9fffff / 0xc00000 / 0xdfffff
- banks (granted that we have the ROM for that, of course)
+ - identify CPU
+ - figure out ROM banking
***************************************************************************/