; Subroutine to detect an 816. Returns
;
; - carry clear and 0 in A for a NMOS 6502 CPU
-; - carry set and 1 in A for a 65c02
+; - carry set and 1 in A for a 65C02
; - carry set and 2 in A for a 65816
; - carry set and 3 in A for a 4510
-; - carry set and 4 in A for a 65sc02
-; - carry set and 5 in A for a 65ce02
+; - carry set and 4 in A for a 65SC02
+; - carry set and 5 in A for a 65CE02
+; - carry set and 6 in A for a HuC6280
+; - carry clear and 7 in A for a 2a03/2a07
;
; This function uses a $1A opcode which is a INA on the 816 and ignored
; (interpreted as a NOP) on a NMOS 6502. There are several CMOS versions
lda #0
inc a ; .byte $1A ; nop on nmos, inc on every cmos
cmp #1
- bcc @L9
+ bcc @L8
-; This is at least a 65C02, check for a 65ce02/4510
+; This is at least a 65C02, check for a 65CE02/4510
- .byte $42,$ea ; neg on 65ce02/4510, nop #$ea on 65c02, wdm $ea on 65816
+ .byte $42,$ea ; neg on 65CE02/4510, nop #$ea on 65C02, wdm $ea on 65816
cmp #1
beq @L6
-; This is at least a 65ce02, check for 4510
+; This is at least a 65CE02, check for 4510
lda #5 ; CPU_65CE02 constant
- .byte $5c ; map on 4510, aug on 65ce02 (acts like 4 byte nop)
+ .byte $5c ; map on 4510, aug on 65CE02 (acts like 4 byte nop)
lda #3 ; CPU_4510 constant
nop
bne @L9
+; 6502 type of cpu, check for a 2a03/2a07
+@L8:
+ sed ; set decimal mode, no decimal mode on the 2a03/2a07
+ lda #9
+ clc
+ adc #1 ; $01+$09 = $10 on 6502, $01+$09 = $0a on 2a03/2a07
+ cld
+ cmp #10
+ bne @L5
+ lda #0 ; CPU_6502 constant
+ beq @L9
+@L5:
+ lda #7 ; CPU_2A0x constant
+ bne @L9
+
+; 65C02 cpu type, check for HuC6280
+@L4: ldx #6 ; CPU_HUC6280 constant
+ .byte $22,$ea ; sax nop on HuC6280 (A=$06, X=$01), nop #$ea on 65C02 (A=$01, X=$06)
+ bne @L9
+
; Check for 65816/65802
-@L6: xba ; .byte $eb, put $01 in B accu (nop on 65c02/65sc02)
+@L6: xba ; .byte $eb, put $01 in B accu (nop on 65C02/65SC02)
dec a ; .byte $3a, A=$00
- xba ; .byte $eb, A=$01 if 65816/65802 and A=$00 if 65c02/65sc02
- inc a ; .byte $1a, A=$02 if 65816/65802 and A=$01 if 65c02/65sc02
+ xba ; .byte $eb, A=$01 if 65816/65802 and A=$00 if 65C02/65SC02
+ inc a ; .byte $1a, A=$02 if 65816/65802 and A=$01 if 65C02/65SC02
cmp #2
beq @L9
-; check for 65sc02
+; check for 65SC02
ldy $f7
ldx #0
stx $f7
- .byte $f7,$f7 ; nop nop on 65sc02, smb7 $f7 on 65c02
+ .byte $f7,$f7 ; nop nop on 65SC02, smb7 $f7 on 65C02
ldx $f7
sty $f7
cpx #$00
- bne @L9
+ bne @L4
lda #4 ; CPU_65SC02 constant
@L9: ldx #0 ; Load high byte of word