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Put back 6551 test as a last verification

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Colin Leroy-Mira 2023-10-14 21:51:31 +02:00 committed by Oliver Schmidt
parent 6e035c864e
commit 3107f34ec9
1 changed files with 42 additions and 9 deletions
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51
libsrc/apple2/ser/a2.ssc.s
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@ -145,7 +145,7 @@ ParityTable: ; Table used to translate RS232 parity param
IdOfsTable: ; Table of bytes positions, used to check four
; specific bytes on the slot's firmware to make
; sure this is an SSC (or Apple //c comm port).
; sure this is a serial card.
.byte $05 ; Pascal 1.0 ID byte
.byte $07 ; Pascal 1.0 ID byte
.byte $0B ; Pascal 1.1 generic signature byte
@ -230,12 +230,8 @@ NotIIgs:ldx #<$C000
: ldy IdOfsTable,x ; Check Pascal 1.1 Firmware Protocol ID bytes
lda IdValTable,x
cmp (ptr2),y
beq ByteOK
NoDev: lda #SER_ERR_NO_DEVICE
bne Out
ByteOK: inx
bne NoDev
inx
cpx #IdTableLen
bcc :-
@ -249,8 +245,45 @@ ByteOK: inx
.endif
tax
; Check that this works like an ACIA 6551 is expected to work
lda ACIA_STATUS,x ; Save current values in what we expect to be
sta tmp1 ; the ACIA status register
lda ACIA_CMD,x ; and command register. So we can restore them
sta tmp2 ; if this isn't a 6551.
and #%11111110
sta ACIA_CMD,x ; Disable receiver/transmitter
lda ACIA_CMD,x ; Reload register
and #%00000001
bne NotAcia ; We expect command register bit 0 to be 0
lda tmp2
ora #%00000001 ; Enable receiver/transmitter
sta ACIA_CMD,x
sta tmp3 ; Store it for comparison
lda ACIA_CMD,x ; Is command register what we wrote?
cmp tmp3
bne NotAcia
sta ACIA_STATUS,x ; Reset Acia (value written is not important)
lda ACIA_CMD,x ; Is the Acia disabled now?
and #%00000001
beq AciaOK
NotAcia:lda tmp2 ; Restore original values
sta ACIA_CMD,x
lda tmp1
sta ACIA_STATUS,x
NoDev: lda #SER_ERR_NO_DEVICE
bne Out
; Check if the handshake setting is valid
ldy #SER_PARAMS::HANDSHAKE
AciaOK: ldy #SER_PARAMS::HANDSHAKE
lda (ptr1),y
cmp #SER_HS_HW ; This is all we support
beq HandshakeOK
@ -481,4 +514,4 @@ Send: ldy SendHead ; Get first byte to send
sta ACIA_DATA,x ; Send it
inc SendHead
inc SendFreeCnt
jmp NextByte ; And try next one
bne NextByte ; And try next one