Removed push/pop from GetByte.

After the replacing the rol instructions with bit instructions with a recent chnage, the only reason left to save a to the stack was setting the OutputFlags. But that can be done using x.

Apple2/CommandFirmware.asm

@@ -140,8 +140,8 @@ finishWrite:
  rts
 
 GetByte:
- lda #$1d ;set read flag low
+ ldx #$1d ;set read flag low
- sta OutputFlags
+ stx OutputFlags
 waitRead:
  bit InputFlags
  bpl readByte
@@ -153,13 +153,11 @@ waitRead:
  rts 
 readByte:
  lda InputByte
- pha
+ ldx #$1f ;set all flags high
- lda #$1f ;set all flags high
+ stx OutputFlags
- sta OutputFlags
 finishRead:
  bit InputFlags
  bpl finishRead
- pla
  clc ;success
 end:
  rts

Apple2/DriveFirmware.asm

@@ -174,19 +174,17 @@ finishWrite:
  rts
 
 GetByte:
- lda #$0d ;set read flag low
+ ldx #$0d ;set read flag low
- sta OutputFlags
+ stx OutputFlags
 waitRead:
  bit InputFlags
  bmi waitRead
  lda InputByte
- pha
+ ldx #$0f ;set all flags high
- lda #$0f ;set all flags high
+ stx OutputFlags
- sta OutputFlags
 finishRead:
  bit InputFlags
  bpl finishRead
- pla
 end:
  rts
 

Apple2/FileAccessFirmware.asm

@@ -127,19 +127,17 @@ finishWrite:
  rts
 
 GetByte:
- lda #$2d ;set read flag low
+ ldx #$2d ;set read flag low
- sta OutputFlags
+ stx OutputFlags
 waitRead:
  bit InputFlags
  bmi waitRead
  lda InputByte
- pha
+ ldx #$2f ;set all flags high
- lda #$2f ;set all flags high
+ stx OutputFlags
- sta OutputFlags
 finishRead:
  bit InputFlags
  bpl finishRead
- pla
 end:
  rts
 

Apple2/MenuFirmware.asm

@@ -134,19 +134,17 @@ finishWrite:
  rts
 
 GetByte:
- lda #$3d ;set read flag low
+ ldx #$3d ;set read flag low
- sta OutputFlags
+ stx OutputFlags
 waitRead:
  bit InputFlags
  bmi waitRead
  lda InputByte
- pha
+ ldx #$3f ;set all flags high
- lda #$3f ;set all flags high
+ stx OutputFlags
- sta OutputFlags
 finishRead:
  bit InputFlags
  bpl finishRead
- pla
  rts
 
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