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size-optimized cartridge check

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FeralChild64 committed 2019-09-11 21:50:48 +02:00
1 parent 13b7172ed5
commit 021c9b3189
3 files changed
+8 -9
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c64/kernal/cartridge_check.s
+4 -6
View File
@@ -1,15 +1,13 @@
// c64 prg p263 // c64 prg p263
cartridge_check: cartridge_check:
ldx #$04 ldx #$05
cartridge_check_l1: cartridge_check_l1:
lda CART_SIG,x lda CART_SIG-1,x
cmp cartridge_signature,x cmp cartridge_signature-1,x
bne no_cartridge bne no_cartridge
dex dex
bpl cartridge_check_l1 bne cartridge_check_l1
sec
rts rts
no_cartridge: no_cartridge:
clc
rts rts
c64/kernal/interrupts/fe47.default_nmi_handler.s
+1 -1
View File
@@ -16,7 +16,7 @@ default_nmi_handler:
// XXX confirm NMIs from CIA, or no other NMI will arrive! // XXX confirm NMIs from CIA, or no other NMI will arrive!
jsr cartridge_check jsr cartridge_check
bcc !+ bne !+
jmp (ICART_WARM_START) jmp (ICART_WARM_START)
!: !:
c64/kernal/reset_entry.s
+3 -2
View File
@@ -3,11 +3,12 @@
reset_entry: reset_entry:
// The GPL program at https://github.com/Klaus2m5/6502_65C02_functional_tests/blob/master/6502_functional_test.a65 // The GPL program at https://github.com/Klaus2m5/6502_65C02_functional_tests/blob/master/6502_functional_test.a65
// uses the following initial reset sequence // uses the following initial reset sequence
// affirmed by c64 PRG p269 // affirmed by c64 PRG p269
cld cld
ldx #$ff ldx #$FF
txs txs
sei sei
@@ -18,7 +19,7 @@ reset_entry:
// C64 PRG p269 // C64 PRG p269
jsr cartridge_check jsr cartridge_check
bcc !+ bne !+
jmp (ICART_COLD_START) jmp (ICART_COLD_START)
!: !:
// Initialising IO is obviously required. Also indicated by c64 prg p269. // Initialising IO is obviously required. Also indicated by c64 prg p269.