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Apple 2 SSC: Handle SER_HS_NONE with no performance impact

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This commit is contained in:
Colin Leroy-Mira
2023-11-03 07:50:28 +01:00
committed by Oliver Schmidt
parent 94239525ca
commit 8a797095c1
1 changed files with 8 additions and 8 deletions
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16
libsrc/apple2/ser/a2.ssc.s
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@@ -87,7 +87,6 @@ SendFreeCnt: .res 1 ; Number of free bytes in send buffer
Stopped: .res 1 ; Flow-stopped flag Stopped: .res 1 ; Flow-stopped flag
RtsOff: .res 1 ; Cached value of command register with RtsOff: .res 1 ; Cached value of command register with
; flow stopped ; flow stopped
HSType: .res 1 ; Flow-control type
RecvBuf: .res 256 ; Receive buffer: 256 bytes RecvBuf: .res 256 ; Receive buffer: 256 bytes
SendBuf: .res 256 ; Send buffer: 256 bytes SendBuf: .res 256 ; Send buffer: 256 bytes
@@ -284,7 +283,7 @@ AciaOK: ldy #SER_PARAMS::HANDSHAKE
bne Out bne Out
HandshakeOK: HandshakeOK:
sta HSType ; Store flow control type sta tmp2 ; Store flow control type
ldy #$00 ; Initialize buffers ldy #$00 ; Initialize buffers
sty Stopped sty Stopped
@@ -335,8 +334,12 @@ BaudOK: sta tmp1
ora #%00001000 ; Enable receive interrupts (RTS low) ora #%00001000 ; Enable receive interrupts (RTS low)
sta ACIA_CMD,x sta ACIA_CMD,x
ldy tmp2 ; Check flow control type
bne Opened
sta RtsOff ; Disable flow control if required
; Done ; Done
stx Index ; Mark port as open Opened: stx Index ; Mark port as open
lda #SER_ERR_OK lda #SER_ERR_OK
Out: Out:
ldx #$00 ; Promote char return value ldx #$00 ; Promote char return value
@@ -476,14 +479,11 @@ SER_IRQ:
bcc Flow ; Assert flow control if buffer space low bcc Flow ; Assert flow control if buffer space low
rts ; Interrupt handled (carry already set) rts ; Interrupt handled (carry already set)
Flow: lda HSType ; Don't touch if no flow control Flow: ldx Index ; Assert flow control if buffer space too low
beq IRQDone
ldx Index ; Assert flow control if buffer space too low
lda RtsOff lda RtsOff
sta ACIA_CMD,x sta ACIA_CMD,x
sta Stopped sta Stopped
IRQDone:sec ; Interrupt handled sec ; Interrupt handled
Done: rts Done: rts
;---------------------------------------------------------------------------- ;----------------------------------------------------------------------------