From 4fd6b7b91e02105f4eabd1db7a7bede276643fc5 Mon Sep 17 00:00:00 2001
From: Terence Boldt <terence@boldt.ca>
Date: Wed, 17 Apr 2024 10:23:32 -0400
Subject: [PATCH] Add assembly of clock driver

---
 Apple2/Clock.Driver.asm | 48 +++++++++++++++++++++++++++++++++++++++++
 Apple2/assemble.cmd     |  7 +++++-
 Apple2/assemble.sh      |  3 +++
 3 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 Apple2/Clock.Driver.asm

diff --git a/Apple2/Clock.Driver.asm b/Apple2/Clock.Driver.asm
new file mode 100644
index 0000000..c238ab2
--- /dev/null
+++ b/Apple2/Clock.Driver.asm
@@ -0,0 +1,48 @@
+enableWriteLang = $C088
+disableWriteLang = $C082
+
+prodosJump = $BF06
+prodosClockCode = $BF07
+prodosMachineId = $BF98
+
+; Find Apple2-IO-RPi card
+
+; Change driver code to point to the card
+
+; Change destination to be ProDOS clock code location
+ lda prodosClockCode
+ sta DriverDestination+1
+ lda prodosClockCode+1
+ sta DriverDestination+2
+
+; Changing RTS to JMP enables clock driver
+ lda #$4C ; jump instruction
+ sta prodosJump
+
+; Enable writing to language card RAM
+; by triggering switch twice
+ lda enableWriteLang
+ lda enableWriteLang
+
+; write driver code to language card RAM
+WriteDriver:
+ ldy #EndDriver-Driver+1
+ lda Driver,y
+DriverDestination:
+ sta $D000,y ; this address gets modified above
+ dey
+ bne WriteDriver
+
+; Disable writing to language card RAM
+ lda disableWriteLang
+
+; Update ProDOS Machine ID to mark clock as enabled
+ lda prodosMachineId
+ ora #$01
+ sta prodosMachineId
+
+ rts
+
+Driver:
+EndDriver:
+ rts
diff --git a/Apple2/assemble.cmd b/Apple2/assemble.cmd
index f2b075a..bdd55c1 100644
--- a/Apple2/assemble.cmd
+++ b/Apple2/assemble.cmd
@@ -88,7 +88,12 @@ ca65 RPi.Command.asm -D HW_TYPE=%HW_TYPE% -o RPi.Command.o --listing RPi.Command
 ld65 RPi.Command.o -o RPi.Command.bin -C ../.cicd/none.cfg 
 @if errorlevel 1 goto exit
 
-del *.o
+ca65 Clock.Driver.asm -D HW_TYPE=%HW_TYPE% -o Clock.Driver.o --listing Clock.Driver.lst
+@if errorlevel 1 goto exit
+ld65 Clock.Driver.o -o Clock.Driver.bin -C ../.cicd/none.cfg 
+@if errorlevel 1 goto exit
+
+cdel *.o
 del DriveFirmware.bin
 del MenuFirmware.bin
 del CommandFirmware.bin
diff --git a/Apple2/assemble.sh b/Apple2/assemble.sh
index 48c667d..685aa85 100755
--- a/Apple2/assemble.sh
+++ b/Apple2/assemble.sh
@@ -51,6 +51,9 @@ ld65 Shell.o -o ../RaspberryPi/driveimage/Shell.bin -C ../.cicd/none.cfg  || exi
 ca65 RPi.Command.asm -D HW_TYPE=$HW_TYPE -o RPi.Command.o --listing RPi.Command.lst || exit 1
 ld65 RPi.Command.o -o ../RaspberryPi/driveimage/RPi.Command.bin -C ../.cicd/none.cfg  || exit 1
 
+ca65 Clock.Driver.asm -D HW_TYPE=$HW_TYPE -o Clock.Driver.o --listing Clock.Driver.lst || exit 1
+ld65 Clock.Driver.o -o ../RaspberryPi/driveimage/Clock.Driver.bin -C ../.cicd/none.cfg  || exit 1
+
 rm ./*.o
 rm DriveFirmware.bin
 rm MenuFirmware.bin