Added support for an alternative hardware type.

The new hardware type has simple UART-type interface. Beside the two data registers, there are only the two bits to indicate readability and writability of the data registers.

Apple2/CommandFirmware.asm

@@ -130,6 +130,7 @@ SendByte:
  bit InputFlags
  bvs SendByte
  sta OutputByte
+.if HW_TYPE = 0
  lda #$1e ; set bit 0 low to indicate write started
  sta OutputFlags 
 finishWrite:
@@ -137,27 +138,34 @@ finishWrite:
  bvc finishWrite
  lda #$1f
  sta OutputFlags
+.endif
  rts
 
 GetByte:
+.if HW_TYPE = 0
  ldx #$1d ;set read flag low
  stx OutputFlags
+.endif
 waitRead:
  bit InputFlags
  bpl readByte
  bit Keyboard ;keypress will abort waiting to read
  bpl waitRead
+.if HW_TYPE = 0
  lda #$1f ;set all flags high and exit
  sta OutputFlags
+.endif
  sec ;failure
  rts 
 readByte:
  lda InputByte
+.if HW_TYPE = 0
  ldx #$1f ;set all flags high
  stx OutputFlags
 finishRead:
  bit InputFlags
  bpl finishRead
+.endif
  clc ;success
 end:
  rts

Apple2/DriveFirmware.asm

@@ -164,6 +164,7 @@ SendByte:
  bit InputFlags
  bvs SendByte
  sta OutputByte
+.if HW_TYPE = 0
  lda #$0e ; set bit 0 low to indicate write started
  sta OutputFlags
 finishWrite:
@@ -171,20 +172,25 @@ finishWrite:
  bvc finishWrite
  lda #$0f
  sta OutputFlags
+.endif
  rts
 
 GetByte:
+.if HW_TYPE = 0
  ldx #$0d ;set read flag low
  stx OutputFlags
+.endif
 waitRead:
  bit InputFlags
  bmi waitRead
  lda InputByte
+.if HW_TYPE = 0
  ldx #$0f ;set all flags high
  stx OutputFlags
 finishRead:
  bit InputFlags
  bpl finishRead
+.endif
 end:
  rts
 

Apple2/FileAccessFirmware.asm

@@ -117,6 +117,7 @@ SendByte:
  bit InputFlags
  bvs SendByte
  sta OutputByte
+.if HW_TYPE = 0
  lda #$2e ; set bit 0 low to indicate write started
  sta OutputFlags 
 finishWrite:
@@ -124,20 +125,25 @@ finishWrite:
  bvc finishWrite
  lda #$2f
  sta OutputFlags
+.endif
  rts
 
 GetByte:
+.if HW_TYPE = 0
  ldx #$2d ;set read flag low
  stx OutputFlags
+.endif
 waitRead:
  bit InputFlags
  bmi waitRead
  lda InputByte
+.if HW_TYPE = 0
  ldx #$2f ;set all flags high
  stx OutputFlags
 finishRead:
  bit InputFlags
  bpl finishRead
+.endif
 end:
  rts
 

Apple2/MenuFirmware.asm

@@ -85,10 +85,11 @@ PrintString:
  iny
  bne PrintString
 
+.if HW_TYPE = 0
+
 WaitForRPi:
- lda InputFlags
- rol
- bcs Reset
+ bit InputFlags
+ bmi Reset
  lda #$ff
  jsr Wait
  lda #'.'+$80
@@ -108,6 +109,37 @@ Reset:
  beq Ok
  jmp Reset
 
+.else
+
+WaitForRPi:
+@1:
+ bit InputFlags
+ bmi @2 
+ lda InputByte
+ jmp @1
+@2:
+ bit InputFlags
+ bpl @4
+ bvs @3
+ lda #ResetCommand
+ sta OutputByte
+@3:
+ lda #$ff
+ jsr Wait
+ lda #'.'+$80
+ jsr PrintChar
+ jmp @2
+@4:
+ lda #$ff
+ jsr Wait
+@5:
+ bit InputFlags
+ bmi Ok 
+ lda InputByte
+ jmp @5
+
+.endif
+
 Ok:
  lda #$8D
  jsr PrintChar
@@ -124,6 +156,7 @@ SendByte:
  bit InputFlags
  bvs SendByte
  sta OutputByte
+.if HW_TYPE = 0
  lda #$3e ; set bit 0 low to indicate write started
  sta OutputFlags 
 finishWrite:
@@ -131,20 +164,25 @@ finishWrite:
  bvc finishWrite
  lda #$3f
  sta OutputFlags
+.endif
  rts
 
 GetByte:
+.if HW_TYPE = 0
  ldx #$3d ;set read flag low
  stx OutputFlags
+.endif
 waitRead:
  bit InputFlags
  bmi waitRead
  lda InputByte
+.if HW_TYPE = 0
  ldx #$3f ;set all flags high
  stx OutputFlags
 finishRead:
  bit InputFlags
  bpl finishRead
+.endif
  rts
 
 Text:

Apple2/RPi.Command.asm

@@ -228,6 +228,7 @@ waitWrite:
  bcs waitWrite
  pla
  sta OutputByte,x
+.if HW_TYPE = 0
  lda #$1e ; set bit 0 low to indicate write started
  sta OutputFlags,x 
 finishWrite:
@@ -237,17 +238,21 @@ finishWrite:
  bcc finishWrite
  lda #$1f
  sta OutputFlags,x
+.endif
  rts
 
 GetByte:
+.if HW_TYPE = 0
  lda #$1d ;set read flag low
  sta OutputFlags,x
+.endif
 waitRead:
  lda InputFlags,x
  rol
  bcs waitRead
 readByte:
  lda InputByte,x
+.if HW_TYPE = 0
  pha
  lda #$1f ;set all flags high
  sta OutputFlags,x
@@ -256,6 +261,7 @@ finishRead:
  rol
  bcc finishRead
  pla
+.endif
  clc ;success
  rts
 

Apple2/Shell.asm

@@ -190,6 +190,7 @@ waitWrite:
  bcs waitWrite
  pla
  sta OutputByte,x
+.if HW_TYPE = 0
  lda #$1e ; set bit 0 low to indicate write started
  sta OutputFlags,x 
 finishWrite:
@@ -199,11 +200,14 @@ finishWrite:
  bcc finishWrite
  lda #$1f
  sta OutputFlags,x
+.endif
  rts
 
 GetByte:
+.if HW_TYPE = 0
  lda #$1d ;set read flag low
  sta OutputFlags,x
+.endif
 waitRead:
  lda InputFlags,x
  rol
@@ -219,6 +223,7 @@ keyPressed:
  and #$7f
  sta OutputByte,x
  bit ClearKeyboard
+.if HW_TYPE = 0
  lda #$1c ;set write flag low too
  sta OutputFlags,x
 finishKeyPress:
@@ -228,9 +233,11 @@ finishKeyPress:
  bcc finishKeyPress
  lda #$1d ;set flags back for reading
  sta OutputFlags,x
+.endif
  jmp waitRead
 readByte:
  lda InputByte,x
+.if HW_TYPE = 0
  pha
  lda #$1f ;set all flags high
  sta OutputFlags,x
@@ -239,6 +246,7 @@ finishRead:
  rol
  bcc finishRead
  pla
+.endif
  clc ;success
 end:
  rts