+++ /dev/null
-;
-; SwiftLink/Turbo-232 v0.90 device driver, by Craig Bruce, 14-Apr-1998.
-;
-; This software is Public Domain. It is in Buddy assembler format.
-;
-; This device driver uses the SwiftLink RS-232 Serial Cartridge, available from
-; Creative Micro Designs, Inc, and also supports the extensions of the Turbo232
-; Serial Cartridge. Both devices are based on the 6551 ACIA chip. It also
-; supports the "hacked" SwiftLink with a 1.8432 MHz crystal.
-;
-; The code assumes that the kernal + I/O are in context. On the C128, call
-; it from Bank 15. On the C64, don't flip out the Kernal unless a suitable
-; NMI catcher is put into the RAM under then Kernal. For the SuperCPU, the
-; interrupt handling assumes that the 65816 is in 6502-emulation mode.
-;
-;--------------------------------------------------------------------------
-;
-; Adapted for the use with the cc65 runtime library by
-; Ullrich von Bassewitz (uz@musoftware.de) 02-May-1999.
-;
-; All external functions are C callable, the return value is an error code.
-;
-
-
- .importzp ptr1, ptr2, tmp1, tmp2
- .import popa, popax
- .export _rs232_init, _rs232_params, _rs232_done, _rs232_get
- .export _rs232_put, _rs232_pause, _rs232_unpause, _rs232_status
-
- .include "c128.inc"
- .include "rs232.inc"
-
-
-NmiExit = $ff33 ;exit address for nmi
-
-ACIA = $DE00
-
-
-
-;----------------------------------------------------------------------------
-;
-; Global variables
-;
-
-.bss
-DropCnt: .res 4 ; Number of bytes lost from rx buffer full
-Initialized: .res 1 ; Flag indicating driver is initialized
-Stopped: .res 1 ; Flow-stopped flag
-RtsOff: .res 1 ;
-Errors: .res 1 ; Number of bytes received in error, low byte
-Turbo232: .res 1 ; Flag indicating turbo-232
-HackedFlag: .res 1 ; Flag indicating hacked-crystal swiftlink
-CpuSpeed: .res 1 ; In MHz
-RecvHead: .res 1 ; Head of receive buffer
-RecvTail: .res 1 ; Tail of receive buffer
-RecvFreeCnt: .res 1 ; Number of bytes in receive buffer
-SendHead: .res 1 ; Head of send buffer
-SendTail: .res 1 ; Tail of send buffer
-SendFreeCnt: .res 1 ; Number of bytes free in send buffer
-BaudCode: .res 1 ; Current baud in effect
-
-; Send and receive buffers: 256 bytes each
-RecvBuf: .res 256
-SendBuf: .res 256
-
-.data
-NmiContinue: .byte $4c ; JMP instruction for NMI save -- continue
-NmiSave: .res 2 ; normal NMI handler
-
-; Switftlink register offsets
-RegData = 0 ; Data register
-RegStatus = 1 ; Status register
-RegCommand = 2 ; Command register
-RegControl = 3 ; Control register
-RegClock = 7 ; Turbo232 external baud-rate generator
-
-
-
-.code
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_init (char hacked);
-; /* Initialize the serial port, install the interrupt handler. The parameter
-; * must be true (non zero) for a hacked swiftlink and false (zero) otherwise.
-; */
-;
-
-_rs232_init:
- bit Initialized ;** shut down if started
- bpl @L1
- pha
- jsr _rs232_done
- pla
-
-;** set hacked-crystal
-
-@L1: sta HackedFlag
-
-;** check for turbo-232
-
- lda #$00
- sta ACIA+RegControl
- tax
- lda ACIA+RegClock
- beq @L3
- dex
-@L3: stx Turbo232
-
-;** get C128 cpu speed
-
- lda $d030
- and #$01
- clc
- adc #1
- sta CpuSpeed
-
-;** check for super-cpu at 20 MHz
-
- bit SCPU_Detect
- bmi @L4
- bit $d0b8
- bvs @L4
- lda #20
- sta CpuSpeed
-
-;** initialize buffers & control
-
-@L4: lda #0
- sta RecvHead
- sta SendHead
- sta RecvTail
- sta SendTail
- sta Errors
- sta Stopped
- lda #255
- sta RecvFreeCnt
- sta SendFreeCnt
-
-;** set up nmi's
-
- lda NMIVec
- ldy NMIVec+1
- sta NmiSave+0
- sty NmiSave+1
- lda #<NmiHandler
- ldy #>NmiHandler
- sta NMIVec
- sty NMIVec+1
-
-;** set default to 2400-8N1, enable interrupts
-
- lda ACIA+RegData
- lda ACIA+RegStatus
- lda #$18
- bit HackedFlag
- bpl @L5
- lda #$1a
-@L5: sta ACIA+RegControl
-
- lda #$01
- sta RtsOff
- ora #$08
- sta ACIA+RegCommand
- lda #$06
- sta BaudCode
-
-; Done
-
- ldx #$ff
- stx Initialized
- inx ; X = 0
- txa ; A = 0
- rts
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_params (unsigned char params, unsigned char parity);
-; /* Set the port parameters. Use a combination of the #defined values above. */
-;
-; Set communication parameters.
-;
-; baud rates stops word | parity
-; --------------------- ----- ----- | ---------
-; $00=50 $08=9600 $00=1 $00=8 | $00=none
-; $01=110 $09=19200 $80=2 $20=7 | $20=odd
-; $02=134.5 $0a=38400 $40=6 | $60=even
-; $03=300 $0b=57600 $60=5 | $A0=mark
-; $04=600 $0c=115200 | $E0=space
-; $05=1200 $0d=230400
-; $06=2400 $0e=future
-; $07=4800 $0f=future
-;
-
-_rs232_params:
- bit Initialized
- bmi @L1
- jmp NotInitialized ; Return an error code
-
-; Save new parity
-
-@L1: and #%11100000
- ora #%00000001
- sta tmp2
-
-; Check cpu speed against baud rate
-
- jsr popa
- sta tmp1
- and #$0f
- cmp #$0c
- bcc @L3
- ldx CpuSpeed
- cpx #1+1
- bcc @L2
- cmp #$0c
- beq @L3
- cpx #4
- bcs @L3
-@L2: lda #RS_ERR_BAUD_TOO_FAST
- bne @L9
-
-; Set baud/parameters
-
-@L3: lda tmp1
- and #$0f
- tax
- lda NormBauds,x
- bit HackedFlag
- bpl @L4
- lda HackBauds,x
-@L4: cmp #$ff
- bne @L5
- lda #RS_ERR_BAUD_NOT_AVAIL
- bne @L9
-
-@L5: tax
- and #$30
- beq @L6
- bit Turbo232
- bmi @L6
- lda #RS_ERR_BAUD_NOT_AVAIL
- bne @L9
-
-@L6: lda tmp1
- and #$0f
- sta BaudCode
- lda tmp1
- and #%11100000
- ora #%00010000
- sta tmp1
- txa
- and #$0f
- ora tmp1
- sta ACIA+RegControl
- txa
- and #%00110000
- beq @L7
- lsr
- lsr
- lsr
- lsr
- eor #%00000011
- sta ACIA+RegClock
-
-; Set new parity
-
-@L7: lda tmp2
- sta RtsOff
- ora #%00001000
- sta ACIA+RegCommand
- lda #0
-@L9: ldx #0
- rts
-
-.rodata
-
-NormBauds:
- .byte $ff,$ff,$ff,$05,$06,$07,$08,$0a,$0c,$0e,$0f,$10,$20,$30,$ff,$ff
-HackBauds:
- .byte $01,$03,$04,$06,$07,$08,$0a,$0c,$0e,$0f,$ff,$ff,$00,$ff,$ff,$ff
- ;in: 0 1 2 3 4 5 6 7 8 9 a b c d e f
- ;baud50 110 134 3 6 12 24 48 96 19 38 57 115 230 exp exp
- ;out masks: $0F=Baud, val$FF=err
- ; $30=t232ExtBaud: $00=none, $10=57.6, $20=115.2, $30=230.4
-.code
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_done (void);
-; /* Close the port, deinstall the interrupt hander. You MUST call this function
-; * before terminating the program, otherwise the machine may crash later. If
-; * in doubt, install an exit handler using atexit(). The function will do
-; * nothing, if it was already called.
-; */
-;
-
-
-_rs232_done:
- bit Initialized ;** check initialized
- bpl @L9
-
-; Stop interrupts, drop DTR
-
- lda RtsOff
- and #%11100010
- ora #%00000010
- sta ACIA+RegCommand
-
-; Restore NMI vector
-
- lda NmiSave+0
- ldy NmiSave+1
- sta NMIVec
- sty NMIVec+1
-
-; Flag uninitialized
-
-@L9: lda #$00
- sta Initialized
- tax
- rts
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_get (char* B);
-; /* Get a character from the serial port. If no characters are available, the
-; * function will return RS_ERR_NO_DATA, so this is not a fatal error.
-; */
-;
-
-_rs232_get:
- bit Initialized
- bpl NotInitialized ; Jump if not initialized
-
-; Check for bytes to send
-
-@L1: sta ptr1
- stx ptr1+1 ; Store pointer to received char
- ldx SendFreeCnt
- cpx #$ff
- beq @L2
- lda #$00
- jsr TryToSend
-
-; Check for buffer empty
-
-@L2: lda RecvFreeCnt
- cmp #$ff
- bne @L3
- lda #RS_ERR_NO_DATA
- ldx #0
- rts
-
-; Check for flow stopped & enough free: release flow control
-
-@L3: ldx Stopped
- beq @L4
- cmp #63
- bcc @L4
- lda #$00
- sta Stopped
- lda RtsOff
- ora #%00001000
- sta ACIA+RegCommand
-
-; Get byte from buffer
-
-@L4: ldx RecvHead
- lda RecvBuf,x
- inc RecvHead
- inc RecvFreeCnt
- ldx #$00
- sta (ptr1,x)
- txa ; Return code = 0
- rts
-
-;----------------------------------------------------------------------------
-;
-; RS232 module not initialized
-
-NotInitialized:
- lda #<RS_ERR_NOT_INITIALIZED
- ldx #>RS_ERR_NOT_INITIALIZED
- rts
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_put (char B);
-; /* Send a character via the serial port. There is a transmit buffer, but
-; * transmitting is not done via interrupt. The function returns
-; * RS_ERR_OVERFLOW if there is no space left in the transmit buffer.
-; */
-;
-
-_rs232_put:
- bit Initialized
- bpl NotInitialized ; Jump if not initialized
-
-; Try to send
-
-@L1: ldx SendFreeCnt
- cpx #$ff
- beq @L2
- pha
- lda #$00
- jsr TryToSend
- pla
-
-; Put byte into send buffer & send
-
-@L2: ldx SendFreeCnt
- bne @L3
- lda #RS_ERR_OVERFLOW
- ldx #$00
- rts
-
-@L3: ldx SendTail
- sta SendBuf,x
- inc SendTail
- dec SendFreeCnt
- lda #$ff
- jsr TryToSend
- lda #$00
- tax
- rts
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_pause (void);
-; /* Assert flow control and disable interrupts. */
-;
-
-_rs232_pause:
- bit Initialized
- bpl NotInitialized ; Jump if not initialized
-
-; Assert flow control
-
-@L1: lda RtsOff
- sta Stopped
- sta ACIA+RegCommand
-
-; Delay for flow stop to be received
-
- ldx BaudCode
- lda PauseTimes,x
- jsr DelayMs
-
-; Stop rx interrupts
-
- lda RtsOff
- ora #$02
- sta ACIA+RegCommand
- lda #0
- tax
- rts
-
-
-.rodata
-; Delay times: 32 byte-receive times in milliseconds, or 100 max.
-; Formula = 320,000 / baud
-PauseTimes:
- .byte 100,100,100,100,100,100,100,067,034,017,009,006,003,002,001,001
- ;in: 0 1 2 3 4 5 6 7 8 9 a b c d e f
- ;baud50 110 134 3 6 12 24 48 96 19 38 57 115 230 exp exp
-.code
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_unpause (void);
-; /* Re-enable interrupts and release flow control */
-;
-
-_rs232_unpause:
- bit Initialized
- bpl NotInitialized ; Jump if not initialized
-
-; Re-enable rx interrupts & release flow control
-
-@L1: lda #$00
- sta Stopped
- lda RtsOff
- ora #%00001000
- sta ACIA+RegCommand
-
-; Poll for stalled char & exit
-
- jsr PollReceive
- lda #0
- tax
- rts
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_status (unsigned char* status,
-; unsigned char* errors);
-; /* Return the serial port status. */
-;
-
-_rs232_status:
- sta ptr2
- stx ptr2+1
- jsr popax
- sta ptr1
- stx ptr1+1
- bit Initialized
- bmi @L1
- jmp NotInitialized
-
-; Get status
-
-@L1: lda ACIA+RegStatus
- ldy #0
- sta (ptr1),y
- jsr PollReceive ; bug-recovery hack
- lda Errors
- sta (ptr2),y
- tya
- tax
-@L9: rts
-
-;----------------------------------------------------------------------------
-;
-; NMI handler
-; C128 NMI overhead=76 cycles: int=7, maxLatency=6, ROMenter=33, ROMexit=30
-; C64 NMI overhead=76 cycles: int=7, maxLatency=6, ROMenter=34, ROMexit=29
-;
-; timing: normal=76+43+9=128 cycles, assertFlow=76+52+9=137 cycles
-;
-; C128 @ 115.2k: 177 cycles avail (fast)
-; C64 @ 57.6k: 177 cycles avail, worstAvail=177-43? = 134
-; SCPU @ 230.4k: 868 cycles avail: for a joke!
-;
-; Because of the C128 banking, the NMI handler must go into the non banked
-; memory, since the ROM NMI entry point will switch to a configuration where
-; only the lowest 16K of RAM are visible. We will place the NMI handler into
-; the LOWCODE segment and map this segment into the lower 16K in the linker
-; config.
-
-.segment "LOWCODE"
-
-NmiHandler:
- lda #MMU_CFG_CC65 ;(2)
- sta MMU_CR ;(4)
- lda ACIA+RegStatus ;(4) ;status ;check for byte received
- and #$08 ;(2)
- beq @L9 ;(2*)
- lda ACIA+RegStatus ;(4) opt ;status ;check for receive errors
- and #$07 ;(2) opt
- beq @L1 ;(3*)opt
- inc Errors ;(5^)opt
-@L1: lda ACIA+RegData ;(4) ;data ;get byte and put into receive buffer
- ldy RecvTail ;(4)
- ldx RecvFreeCnt ;(4)
- beq @L3 ;(2*)
- sta RecvBuf,y ;(5)
- inc RecvTail ;(6)
- dec RecvFreeCnt ;(6)
- cpx #33 ;(2) ;check for buffer space low
- bcc @L2 ;(2*)
- jmp NmiExit ;(3)
-
-; Assert flow control
-
-@L2: lda RtsOff ;(3) ;assert flow control if buffer space too low
- sta ACIA+RegCommand ;(4) ;command
- sta Stopped ;(3)
- jmp NmiExit ;(3)
-
-; Drop this char
-
-@L3: inc DropCnt+0 ;not time-critical
- bne @L4
- inc DropCnt+1
- bne @L4
- inc DropCnt+2
- bne @L4
- inc DropCnt+3
-@L4: jmp NmiExit
-
-@L9: jmp NmiContinue
-
-
-.code
-
-;----------------------------------------------------------------------------
-; Try to send a byte. Internal routine. A = TryHard
-
-TryToSend:
- sta tmp1 ; Remember tryHard flag
-@L0: lda SendFreeCnt
- cmp #$ff
- beq @L3 ; Bail out
-
-; Check for flow stopped
-
-@L1: lda Stopped
- bne @L3 ; Bail out
-
-;** check that swiftlink is ready to send
-
-@L2: lda ACIA+RegStatus
- 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+RegData
- inc SendHead
- inc SendFreeCnt
- jmp @L0
-
-;----------------------------------------------------------------------------
-;
-; PollReceive - poll for rx char
-; This function is useful in odd cases where the 6551 has a character in
-; it but it fails to raise an NMI. It might be edge-triggering conditions?
-; Actually, I'm not entirely sure that this condition can still arrise, but
-; calling this function does no harm.
-;
-
-PollReceive:
- lda #$08
- and ACIA+RegStatus
- beq @L9
- and ACIA+RegStatus
- beq @L9
- lda ACIA+RegData
- ldx RecvFreeCnt
- beq @L9
- ldx RecvTail
- sta RecvBuf,x
- inc RecvTail
- dec RecvFreeCnt
-@L9: rts
-
-;----------------------------------------------------------------------------
-;
-; DelayMs : delay for given number of milliseconds
-; This implementation isn't very rigerous; it merely delays for the
-; approximate number of clock cycles for the processor speed.
-; Algorithm:
-; repeat for number of milliseconds:
-; repeat for number of MHz of cpu speed:
-; delay for 1017 clock cycles
-;
-
-DelayMs: ;( .A=milliseconds )
-@L1: ldy CpuSpeed
-@L2: ldx #203 ;(2)
-@L3: dex ;(2)
- bne @L3 ;(3) // 1017 cycles
- dey
- bne @L2
- sec
- sbc #1
- bne @L1
- rts
-
-.end
-
-
-
+++ /dev/null
-;
-; SwiftLink/Turbo-232 v0.90 device driver, by Craig Bruce, 14-Apr-1998.
-;
-; This software is Public Domain. It is in Buddy assembler format.
-;
-; This device driver uses the SwiftLink RS-232 Serial Cartridge, available from
-; Creative Micro Designs, Inc, and also supports the extensions of the Turbo232
-; Serial Cartridge. Both devices are based on the 6551 ACIA chip. It also
-; supports the "hacked" SwiftLink with a 1.8432 MHz crystal.
-;
-; The code assumes that the kernal + I/O are in context. On the C128, call
-; it from Bank 15. On the C64, don't flip out the Kernal unless a suitable
-; NMI catcher is put into the RAM under then Kernal. For the SuperCPU, the
-; interrupt handling assumes that the 65816 is in 6502-emulation mode.
-;
-;--------------------------------------------------------------------------
-;
-; Adapted for the use with the cc65 runtime library by
-; Ullrich von Bassewitz (uz@musoftware.de) 02-May-1999.
-;
-; All external functions are C callable, the return value is an error code.
-;
-
-
- .importzp ptr1, ptr2, tmp1, tmp2
- .import popa, popax
- .export _rs232_init, _rs232_params, _rs232_done, _rs232_get
- .export _rs232_put, _rs232_pause, _rs232_unpause, _rs232_status
-
- .include "c64.inc"
- .include "rs232.inc"
-
-
-NmiExit = $febc ;exit address for nmi
-
-ACIA = $DE00
-
-
-
-;----------------------------------------------------------------------------
-;
-; Global variables
-;
-
-.bss
-DropCnt: .res 4 ; Number of bytes lost from rx buffer full
-Initialized: .res 1 ; Flag indicating driver is initialized
-Stopped: .res 1 ; Flow-stopped flag
-RtsOff: .res 1 ;
-Errors: .res 1 ; Number of bytes received in error, low byte
-Turbo232: .res 1 ; Flag indicating turbo-232
-HackedFlag: .res 1 ; Flag indicating hacked-crystal swiftlink
-CpuSpeed: .res 1 ; In MHz
-RecvHead: .res 1 ; Head of receive buffer
-RecvTail: .res 1 ; Tail of receive buffer
-RecvFreeCnt: .res 1 ; Number of bytes in receive buffer
-SendHead: .res 1 ; Head of send buffer
-SendTail: .res 1 ; Tail of send buffer
-SendFreeCnt: .res 1 ; Number of bytes free in send buffer
-BaudCode: .res 1 ; Current baud in effect
-
-; Send and receive buffers: 256 bytes each
-RecvBuf: .res 256
-SendBuf: .res 256
-
-.data
-NmiContinue: .byte $4c ; JMP instruction for NMI save -- continue
-NmiSave: .res 2 ; normal NMI handler
-
-; Switftlink register offsets
-RegData = 0 ; Data register
-RegStatus = 1 ; Status register
-RegCommand = 2 ; Command register
-RegControl = 3 ; Control register
-RegClock = 7 ; Turbo232 external baud-rate generator
-
-
-
-.code
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_init (char hacked);
-; /* Initialize the serial port, install the interrupt handler. The parameter
-; * must be true (non zero) for a hacked swiftlink and false (zero) otherwise.
-; */
-;
-
-_rs232_init:
- bit Initialized ;** shut down if started
- bpl @L1
- pha
- jsr _rs232_done
- pla
-
-;** set hacked-crystal
-
-@L1: sta HackedFlag
-
-;** check for turbo-232
-
- lda #$00
- sta ACIA+RegControl
- tax
- lda ACIA+RegClock
- beq @L3
- dex
-@L3: stx Turbo232
-
-;** get C128/C64 cpu speed
-
- lda #1
- sta CpuSpeed
-
-;** check for super-cpu at 20 MHz
-
- bit $d0bc
- bmi @L4
- bit $d0b8
- bvs @L4
- lda #20
- sta CpuSpeed
-
-;** initialize buffers & control
-
-@L4: lda #0
- sta RecvHead
- sta SendHead
- sta RecvTail
- sta SendTail
- sta Errors
- sta Stopped
- lda #255
- sta RecvFreeCnt
- sta SendFreeCnt
-
-;** set up nmi's
-
- lda NMIVec
- ldy NMIVec+1
- sta NmiSave+0
- sty NmiSave+1
- lda #<NmiHandler
- ldy #>NmiHandler
- sta NMIVec
- sty NMIVec+1
-
-;** set default to 2400-8N1, enable interrupts
-
- lda ACIA+RegData
- lda ACIA+RegStatus
- lda #$18
- bit HackedFlag
- bpl @L5
- lda #$1a
-@L5: sta ACIA+RegControl
-
- lda #$01
- sta RtsOff
- ora #$08
- sta ACIA+RegCommand
- lda #$06
- sta BaudCode
-
-; Done
-
- ldx #$ff
- stx Initialized
- inx ; X = 0
- txa ; A = 0
- rts
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_params (unsigned char params, unsigned char parity);
-; /* Set the port parameters. Use a combination of the #defined values above. */
-;
-; Set communication parameters.
-;
-; baud rates stops word | parity
-; --------------------- ----- ----- | ---------
-; $00=50 $08=9600 $00=1 $00=8 | $00=none
-; $01=110 $09=19200 $80=2 $20=7 | $20=odd
-; $02=134.5 $0a=38400 $40=6 | $60=even
-; $03=300 $0b=57600 $60=5 | $A0=mark
-; $04=600 $0c=115200 | $E0=space
-; $05=1200 $0d=230400
-; $06=2400 $0e=future
-; $07=4800 $0f=future
-;
-
-_rs232_params:
- bit Initialized
- bmi @L1
- jmp NotInitialized ; Return an error code
-
-; Save new parity
-
-@L1: and #%11100000
- ora #%00000001
- sta tmp2
-
-; Check cpu speed against baud rate
-
- jsr popa
- sta tmp1
- and #$0f
- cmp #$0c
- bcc @L3
- ldx CpuSpeed
- cpx #1+1
- bcc @L2
- cmp #$0c
- beq @L3
- cpx #4
- bcs @L3
-@L2: lda #RS_ERR_BAUD_TOO_FAST
- bne @L9
-
-; Set baud/parameters
-
-@L3: lda tmp1
- and #$0f
- tax
- lda NormBauds,x
- bit HackedFlag
- bpl @L4
- lda HackBauds,x
-@L4: cmp #$ff
- bne @L5
- lda #RS_ERR_BAUD_NOT_AVAIL
- bne @L9
-
-@L5: tax
- and #$30
- beq @L6
- bit Turbo232
- bmi @L6
- lda #RS_ERR_BAUD_NOT_AVAIL
- bne @L9
-
-@L6: lda tmp1
- and #$0f
- sta BaudCode
- lda tmp1
- and #%11100000
- ora #%00010000
- sta tmp1
- txa
- and #$0f
- ora tmp1
- sta ACIA+RegControl
- txa
- and #%00110000
- beq @L7
- lsr
- lsr
- lsr
- lsr
- eor #%00000011
- sta ACIA+RegClock
-
-; Set new parity
-
-@L7: lda tmp2
- sta RtsOff
- ora #%00001000
- sta ACIA+RegCommand
- lda #0
-@L9: ldx #0
- rts
-
-.rodata
-
-NormBauds:
- .byte $ff,$ff,$ff,$05,$06,$07,$08,$0a,$0c,$0e,$0f,$10,$20,$30,$ff,$ff
-HackBauds:
- .byte $01,$03,$04,$06,$07,$08,$0a,$0c,$0e,$0f,$ff,$ff,$00,$ff,$ff,$ff
- ;in: 0 1 2 3 4 5 6 7 8 9 a b c d e f
- ;baud50 110 134 3 6 12 24 48 96 19 38 57 115 230 exp exp
- ;out masks: $0F=Baud, val$FF=err
- ; $30=t232ExtBaud: $00=none, $10=57.6, $20=115.2, $30=230.4
-.code
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_done (void);
-; /* Close the port, deinstall the interrupt hander. You MUST call this function
-; * before terminating the program, otherwise the machine may crash later. If
-; * in doubt, install an exit handler using atexit(). The function will do
-; * nothing, if it was already called.
-; */
-;
-
-
-_rs232_done:
- bit Initialized ;** check initialized
- bpl @L9
-
-; Stop interrupts, drop DTR
-
- lda RtsOff
- and #%11100010
- ora #%00000010
- sta ACIA+RegCommand
-
-; Restore NMI vector
-
- lda NmiSave+0
- ldy NmiSave+1
- sta NMIVec
- sty NMIVec+1
-
-; Flag uninitialized
-
-@L9: lda #$00
- sta Initialized
- tax
- rts
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_get (char* B);
-; /* Get a character from the serial port. If no characters are available, the
-; * function will return RS_ERR_NO_DATA, so this is not a fatal error.
-; */
-;
-
-_rs232_get:
- bit Initialized
- bpl NotInitialized ; Jump if not initialized
-
-; Check for bytes to send
-
- sta ptr1
- stx ptr1+1 ; Store pointer to received char
- ldx SendFreeCnt
- cpx #$ff
- beq @L2
- lda #$00
- jsr TryToSend
-
-; Check for buffer empty
-
-@L2: lda RecvFreeCnt ; (25)
- cmp #$ff
- bne @L3
- lda #RS_ERR_NO_DATA
- ldx #0
- rts
-
-; Check for flow stopped & enough free: release flow control
-
-@L3: ldx Stopped ; (34)
- beq @L4
- cmp #63
- bcc @L4
- lda #$00
- sta Stopped
- lda RtsOff
- ora #%00001000
- sta ACIA+RegCommand
-
-; Get byte from buffer
-
-@L4: ldx RecvHead ; (41)
- lda RecvBuf,x
- inc RecvHead
- inc RecvFreeCnt
- ldx #$00 ; (59)
- sta (ptr1,x)
- txa ; Return code = 0
- rts
-
-;----------------------------------------------------------------------------
-;
-; RS232 module not initialized
-
-NotInitialized:
- lda #<RS_ERR_NOT_INITIALIZED
- ldx #>RS_ERR_NOT_INITIALIZED
- rts
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_put (char B);
-; /* Send a character via the serial port. There is a transmit buffer, but
-; * transmitting is not done via interrupt. The function returns
-; * RS_ERR_OVERFLOW if there is no space left in the transmit buffer.
-; */
-;
-
-_rs232_put:
- bit Initialized
- bpl NotInitialized ; Jump if not initialized
-
-; Try to send
-
- ldx SendFreeCnt
- cpx #$ff
- beq @L2
- pha
- lda #$00
- jsr TryToSend
- pla
-
-; Put byte into send buffer & send
-
-@L2: ldx SendFreeCnt
- bne @L3
- lda #RS_ERR_OVERFLOW
- ldx #$00
- rts
-
-@L3: ldx SendTail
- sta SendBuf,x
- inc SendTail
- dec SendFreeCnt
- lda #$ff
- jsr TryToSend
- lda #$00
- tax
- rts
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_pause (void);
-; /* Assert flow control and disable interrupts. */
-;
-
-_rs232_pause:
- bit Initialized
- bpl NotInitialized ; Jump if not initialized
-
-; Assert flow control
-
- lda RtsOff
- sta Stopped
- sta ACIA+RegCommand
-
-; Delay for flow stop to be received
-
- ldx BaudCode
- lda PauseTimes,x
- jsr DelayMs
-
-; Stop rx interrupts
-
- lda RtsOff
- ora #$02
- sta ACIA+RegCommand
- lda #0
- tax
- rts
-
-
-.rodata
-; Delay times: 32 byte-receive times in milliseconds, or 100 max.
-; Formula = 320,000 / baud
-PauseTimes:
- .byte 100,100,100,100,100,100,100,067,034,017,009,006,003,002,001,001
- ;in: 0 1 2 3 4 5 6 7 8 9 a b c d e f
- ;baud50 110 134 3 6 12 24 48 96 19 38 57 115 230 exp exp
-.code
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_unpause (void);
-; /* Re-enable interrupts and release flow control */
-;
-
-_rs232_unpause:
- bit Initialized
- bpl NotInitialized ; Jump if not initialized
-
-; Re-enable rx interrupts & release flow control
-
-@L1: lda #$00
- sta Stopped
- lda RtsOff
- ora #%00001000
- sta ACIA+RegCommand
-
-; Poll for stalled char & exit
-
- jsr PollReceive
- lda #0
- tax
- rts
-
-;----------------------------------------------------------------------------
-;
-; unsigned char __fastcall__ rs232_status (unsigned char* status,
-; unsigned char* errors);
-; /* Return the serial port status. */
-;
-
-_rs232_status:
- sta ptr2
- stx ptr2+1
- jsr popax
- sta ptr1
- stx ptr1+1
- bit Initialized
- bmi @L1
- jmp NotInitialized
-
-; Get status
-
-@L1: lda ACIA+RegStatus
- ldy #0
- sta (ptr1),y
- jsr PollReceive ; bug-recovery hack
- lda Errors
- sta (ptr2),y
- tya
- tax
-@L9: rts
-
-;----------------------------------------------------------------------------
-;
-; NMI handler
-; C128 NMI overhead=76 cycles: int=7, maxLatency=6, ROMenter=33, ROMexit=30
-; C64 NMI overhead=76 cycles: int=7, maxLatency=6, ROMenter=34, ROMexit=29
-;
-; timing: normal=76+43+9=128 cycles, assertFlow=76+52+9=137 cycles
-;
-; C128 @ 115.2k: 177 cycles avail (fast)
-; C64 @ 57.6k: 177 cycles avail, worstAvail=177-43? = 134
-; SCPU @ 230.4k: 868 cycles avail: for a joke!
-;
-
-NmiHandler:
- pha
- lda ACIA+RegStatus ;(4) ;status ;check for byte received
- and #$08 ;(2)
- beq @L9 ;(2*)
- cld
- txa
- pha
- tya
- pha
- lda ACIA+RegStatus ;(4) opt ;status ;check for receive errors
- and #$07 ;(2) opt
- beq @L1 ;(3*)opt
- inc Errors ;(5^)opt
-@L1: lda ACIA+RegData ;(4) ;data ;get byte and put into receive buffer
- ldy RecvTail ;(4)
- ldx RecvFreeCnt ;(4)
- beq @L3 ;(2*)
- sta RecvBuf,y ;(5)
- inc RecvTail ;(6)
- dec RecvFreeCnt ;(6)
- cpx #33 ;(2) ;check for buffer space low
- bcc @L2 ;(2*)
- jmp NmiExit ;(3)
-
-; Assert flow control
-
-@L2: lda RtsOff ;(3) ;assert flow control if buffer space too low
- sta ACIA+RegCommand ;(4) ;command
- sta Stopped ;(3)
- jmp NmiExit ;(3)
-
-; Drop this char
-
-@L3: inc DropCnt+0 ; not time-critical
- bne @L4
- inc DropCnt+1
- bne @L4
- inc DropCnt+2
- bne @L4
- inc DropCnt+3
-@L4: jmp NmiExit
-
-@L9: pla
- jmp NmiContinue
-
-;----------------------------------------------------------------------------
-; Try to send a byte. Internal routine. A = TryHard
-
-TryToSend:
- sta tmp1 ; Remember tryHard flag
-@L0: lda SendFreeCnt
- cmp #$ff
- beq @L3 ; Bail out
-
-; Check for flow stopped
-
-@L1: lda Stopped
- bne @L3 ; Bail out
-
-;** check that swiftlink is ready to send
-
-@L2: lda ACIA+RegStatus
- 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+RegData
- inc SendHead
- inc SendFreeCnt
- jmp @L0
-
-
-;----------------------------------------------------------------------------
-;
-; PollReceive - poll for rx char
-; This function is useful in odd cases where the 6551 has a character in
-; it but it fails to raise an NMI. It might be edge-triggering conditions?
-; Actually, I'm not entirely sure that this condition can still arrise, but
-; calling this function does no harm.
-;
-
-PollReceive:
- lda #$08
- and ACIA+RegStatus
- beq @L9
- and ACIA+RegStatus
- beq @L9
- lda ACIA+RegData
- ldx RecvFreeCnt
- beq @L9
- ldx RecvTail
- sta RecvBuf,x
- inc RecvTail
- dec RecvFreeCnt
-@L9: rts
-
-;----------------------------------------------------------------------------
-;
-; DelayMs : delay for given number of milliseconds
-; This implementation isn't very rigerous; it merely delays for the
-; approximate number of clock cycles for the processor speed.
-; Algorithm:
-; repeat for number of milliseconds:
-; repeat for number of MHz of cpu speed:
-; delay for 1017 clock cycles
-;
-
-DelayMs: ;( .A=milliseconds )
-@L1: ldy CpuSpeed
-@L2: ldx #203 ;(2)
-@L3: dex ;(2)
- bne @L3 ;(3) // 1017 cycles
- dey
- bne @L2
- sec
- sbc #1
- bne @L1
- rts
-
-.end
-
-
-
projects / cc65 / commitdiff