.include "zeropage.inc"
.include "ser-kernel.inc"
.include "ser-error.inc"
- .include "c128.inc"
+ .include "c128.inc"
; ------------------------------------------------------------------------
.word PUT
.word STATUS
.word IOCTL
- .word IRQ
+ .word IRQ
;----------------------------------------------------------------------------
; I/O definitions
-ACIA = $DE00
+ACIA = $DE00
ACIA_DATA = ACIA+0 ; Data register
ACIA_STATUS = ACIA+1 ; Status register
ACIA_CMD = ACIA+2 ; Command register
.org $1150 ; BASIC graphics area
.proc NmiStub
- lda #MMU_CFG_CC65 ; Bank 0 with kernal ROM...
- sta MMU_CR ; ...enable
+ lda #MMU_CFG_CC65 ; Bank 0 with kernal ROM...
+ sta MMU_CR ; ...enable
jsr NmiHandler ; Call the actual NMI handler
- lda #$00 ; Get ROM config...
- sta MMU_CR ; ...and enable it
+ lda #$00 ; Get ROM config...
+ sta MMU_CR ; ...and enable it
Vector := *+1
.byte $4C ; Jump to the saved IRQ vector
; Deactivate DTR and disable 6551 interrupts
- lda #%00001010
- sta ACIA_CMD
+ lda #%00001010
+ sta ACIA_CMD
; Copy the NMI stub into low memory
; Set up the nmi vector
- lda NMIVec
- ldy NMIVec+1
- sta NmiStub::Vector+0
- sty NmiStub::Vector+1
- lda #<NmiStub
- ldy #>NmiStub
-SetNMI: sta NMIVec
- sty NMIVec+1
+ lda NMIVec
+ ldy NMIVec+1
+ sta NmiStub::Vector+0
+ sty NmiStub::Vector+1
+ lda #<NmiStub
+ ldy #>NmiStub
+SetNMI: sta NMIVec
+ sty NMIVec+1
; Done, return an error code
lda #<SER_ERR_OK
tax ; A is zero
- rts
+ rts
;----------------------------------------------------------------------------
; UNINSTALL routine. Is called before the driver is removed from memory.
; Stop interrupts, drop DTR
- lda #%00001010
- sta ACIA_CMD
+ lda #%00001010
+ sta ACIA_CMD
; Restore NMI vector and return OK
- lda NmiStub::Vector+0
- ldy NmiStub::Vector+1
- jmp SetNMI
+ lda NmiStub::Vector+0
+ ldy NmiStub::Vector+1
+ jmp SetNMI
;----------------------------------------------------------------------------
; PARAMS routine. A pointer to a ser_params structure is passed in ptr1.
; Check if the handshake setting is valid
- ldy #SER_PARAMS::HANDSHAKE ; Handshake
+ ldy #SER_PARAMS::HANDSHAKE ; Handshake
lda (ptr1),y
- cmp #SER_HS_HW ; This is all we support
- bne InvParam
+ cmp #SER_HS_HW ; This is all we support
+ bne InvParam
; Initialize buffers
lda (ptr1),y ; Baudrate index
tay
lda BaudTable,y ; Get 6551 value
- bmi InvBaud ; Branch if rate not supported
+ bmi InvBaud ; Branch if rate not supported
sta tmp1
- ldy #SER_PARAMS::DATABITS ; Databits
+ ldy #SER_PARAMS::DATABITS ; Databits
lda (ptr1),y
tay
lda BitTable,y
ora tmp1
sta tmp1
- ldy #SER_PARAMS::STOPBITS ; Stopbits
+ ldy #SER_PARAMS::STOPBITS ; Stopbits
lda (ptr1),y
tay
lda StopTable,y
ora tmp1
- ora #%00010000 ; Receiver clock source = baudrate
- sta ACIA_CTRL
+ ora #%00010000 ; Receiver clock source = baudrate
+ sta ACIA_CTRL
; Set the value for the command register. We remember the base value in
; RtsOff, since we will have to manipulate ACIA_CMD often.
- ldy #SER_PARAMS::PARITY ; Parity
+ ldy #SER_PARAMS::PARITY ; Parity
lda (ptr1),y
tay
lda ParityTable,y
- ora #%00000001 ; DTR active
- sta RtsOff
- ora #%00001000 ; Enable receive interrupts
- sta ACIA_CMD
+ ora #%00000001 ; DTR active
+ sta RtsOff
+ ora #%00001000 ; Enable receive interrupts
+ sta ACIA_CMD
; Done
lda #<SER_ERR_OK
tax ; A is zero
- rts
+ rts
; Invalid parameter
InvParam:
- lda #<SER_ERR_INIT_FAILED
- ldx #>SER_ERR_INIT_FAILED
- rts
+ lda #<SER_ERR_INIT_FAILED
+ ldx #>SER_ERR_INIT_FAILED
+ rts
; Baud rate not available
; Stop interrupts, drop DTR
- lda #%00001010
- sta ACIA_CMD
+ lda #%00001010
+ sta ACIA_CMD
; Initalize buffers. Returns zero in a
lda #<SER_ERR_OK
tax ; A is zero
- rts
+ rts
;----------------------------------------------------------------------------
; GET: Will fetch a character from the receive buffer and store it into the
; return.
;
-GET: ldx SendFreeCnt ; Send data if necessary
- inx ; X == $FF?
- beq @L1
- lda #$00
- jsr TryToSend
+GET: ldx SendFreeCnt ; Send data if necessary
+ inx ; X == $FF?
+ beq @L1
+ lda #$00
+ jsr TryToSend
; Check for buffer empty
-@L1: lda RecvFreeCnt ; (25)
- cmp #$ff
- bne @L2
- lda #<SER_ERR_NO_DATA
- ldx #>SER_ERR_NO_DATA
- rts
+@L1: lda RecvFreeCnt ; (25)
+ cmp #$ff
+ bne @L2
+ lda #<SER_ERR_NO_DATA
+ ldx #>SER_ERR_NO_DATA
+ rts
; Check for flow stopped & enough free: release flow control
-@L2: ldx Stopped ; (34)
- beq @L3
- cmp #63
- bcc @L3
- lda #$00
- sta Stopped
- lda RtsOff
- ora #%00001000
- sta ACIA_CMD
+@L2: ldx Stopped ; (34)
+ beq @L3
+ cmp #63
+ bcc @L3
+ lda #$00
+ sta Stopped
+ lda RtsOff
+ ora #%00001000
+ sta ACIA_CMD
; Get byte from buffer
-@L3: ldx RecvHead ; (41)
- lda RecvBuf,x
- inc RecvHead
- inc RecvFreeCnt
- ldx #$00 ; (59)
- sta (ptr1,x)
- txa ; Return code = 0
- rts
+@L3: ldx RecvHead ; (41)
+ lda RecvBuf,x
+ inc RecvHead
+ inc RecvFreeCnt
+ ldx #$00 ; (59)
+ sta (ptr1,x)
+ txa ; Return code = 0
+ rts
;----------------------------------------------------------------------------
; PUT: Output character in A.
; Try to send
- ldx SendFreeCnt
- inx ; X = $ff?
- beq @L2
- pha
- lda #$00
- jsr TryToSend
- pla
+ ldx SendFreeCnt
+ inx ; X = $ff?
+ beq @L2
+ pha
+ lda #$00
+ jsr TryToSend
+ pla
; Put byte into send buffer & send
-@L2: ldx SendFreeCnt
- bne @L3
- lda #<SER_ERR_OVERFLOW ; X is already zero
- rts
-
-@L3: ldx SendTail
- sta SendBuf,x
- inc SendTail
- dec SendFreeCnt
- lda #$ff
- jsr TryToSend
- lda #<SER_ERR_OK
- tax
- rts
+@L2: ldx SendFreeCnt
+ bne @L3
+ lda #<SER_ERR_OVERFLOW ; X is already zero
+ rts
+
+@L3: ldx SendTail
+ sta SendBuf,x
+ inc SendTail
+ dec SendFreeCnt
+ lda #$ff
+ jsr TryToSend
+ lda #<SER_ERR_OK
+ tax
+ rts
;----------------------------------------------------------------------------
; STATUS: Return the status in the variable pointed to by ptr1.
; Must return an error code in a/x.
;
-STATUS: lda ACIA_STATUS
- ldx #0
- sta (ptr1,x)
- txa ; SER_ERR_OK
+STATUS: lda ACIA_STATUS
+ ldx #0
+ sta (ptr1,x)
+ txa ; SER_ERR_OK
rts
;----------------------------------------------------------------------------
; saved by the ROM code.
NmiHandler:
- lda ACIA_STATUS ;(4) ;status ;check for byte received
- and #$08 ;(2)
- beq @L9 ;(2*)
- cld
- lda ACIA_DATA ;(4) data ;get byte and put into receive buffer
- ldy RecvTail ;(4)
- ldx RecvFreeCnt ;(4)
- beq @L9 ;(2*) Jump if no space in receive buffer
- sta RecvBuf,y ;(5)
- inc RecvTail ;(6)
- dec RecvFreeCnt ;(6)
- cpx #33 ;(2) check for buffer space low
- bcc @L2 ;(2*)
- rts
+ lda ACIA_STATUS ;(4) ;status ;check for byte received
+ and #$08 ;(2)
+ beq @L9 ;(2*)
+ cld
+ lda ACIA_DATA ;(4) data ;get byte and put into receive buffer
+ ldy RecvTail ;(4)
+ ldx RecvFreeCnt ;(4)
+ beq @L9 ;(2*) Jump if no space in receive buffer
+ sta RecvBuf,y ;(5)
+ inc RecvTail ;(6)
+ dec RecvFreeCnt ;(6)
+ cpx #33 ;(2) check for buffer space low
+ bcc @L2 ;(2*)
+ rts
; Assert flow control
-@L2: lda RtsOff ;(3) assert flow control if buffer space too low
- sta ACIA_CMD ;(4) command
- sta Stopped ;(3)
+@L2: lda RtsOff ;(3) assert flow control if buffer space too low
+ sta ACIA_CMD ;(4) command
+ sta Stopped ;(3)
@L9: rts
;----------------------------------------------------------------------------
.proc TryToSend
- sta tmp1 ; Remember tryHard flag
-@L0: lda SendFreeCnt
- cmp #$ff
- beq @L3 ; Bail out
+ sta tmp1 ; Remember tryHard flag
+@L0: lda SendFreeCnt
+ cmp #$ff
+ beq @L3 ; Bail out
; Check for flow stopped
-@L1: lda Stopped
- bne @L3 ; Bail out
+@L1: lda Stopped
+ bne @L3 ; Bail out
; Check that swiftlink is ready to send
-@L2: lda ACIA_STATUS
- and #$10
- bne @L4
- bit tmp1 ;keep trying if must try hard
- bmi @L0
-@L3: rts
+@L2: lda ACIA_STATUS
+ and #$10
+ bne @L4
+ bit tmp1 ;keep trying if must try hard
+ bmi @L0
+@L3: rts
; Send byte and try again
-@L4: ldx SendHead
- lda SendBuf,x
- sta ACIA_DATA
- inc SendHead
- inc SendFreeCnt
- jmp @L0
+@L4: ldx SendHead
+ lda SendBuf,x
+ sta ACIA_DATA
+ inc SendHead
+ inc SendFreeCnt
+ jmp @L0
.endproc
; Initialize buffers
InitBuffers:
- ldx #0
+ ldx #0
stx Stopped
- stx RecvHead
- stx RecvTail
- stx SendHead
- stx SendTail
+ stx RecvHead
+ stx RecvTail
+ stx SendHead
+ stx SendTail
dex ; X = 255
- stx RecvFreeCnt
- stx SendFreeCnt
+ stx RecvFreeCnt
+ stx SendFreeCnt
rts
projects / cc65 / blobdiff