; Subroutine to detect an 816. Returns
;
; - carry clear and 0 in A for a NMOS 6502 CPU
-; - carry set and 1 in A for some CMOS 6502 CPU
+; - 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
;
; 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
cmp #1
bcc @L9
-; This is at least a 65C02, check for a 4510
+; This is at least a 65C02, check for a 65ce02/4510
- .byte $42,$ea ; neg on 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
- bne @L8
+ beq @L6
+
+; check for 4510
+
+ lda #5 ; CPU_65CE02 constant
+ .byte $5c ; map on 4510, aug on 65ce02 (acts like 4 byte nop)
+ lda #3 ; CPU_4510 constant
+ nop
+ bne @L9
+
+; check for 65sc02
+
+@L6: ldy $f7
+ ldx #$00
+ stx $f7
+ .byte $f7,$f7 ; nop nop on 65sc02, smb7 $f7 on 65c02 and 65816
+ ldx $f7
+ sty $f7
+ cpx #$00
+ bne @L7
+ lda #4 ; CPU_65SC02 constant
+ bne @L9
; check for 65816; after 4510, because $eb there is row (rotate word)
- xba ; .byte $eb, put $01 in B accu
+@L7: xba ; .byte $eb, put $01 in B accu
dec a ; .byte $3a, A=$00 if 65C02
xba ; .byte $eb, get $01 back if 65816
inc a ; .byte $1a, make $01/$02
.byte $2c ; bit instruction to skip next command
-@L8: lda #3 ; CPU_4510 constant
@L9: ldx #0 ; Load high byte of word
rts