Created a target and a library for the Commander X16 prototype computer.

2019-09-27 03:38:51 -04:00
parent 0896deedef
commit 18afc7c703
49 changed files with 2440 additions and 59 deletions
--- a/libsrc/cx16/irq.s
+++ b/libsrc/cx16/irq.s
@@ -0,0 +1,48 @@
+;
+; IRQ handling (CX16 version)
+;
+
+        .export         initirq, doneirq
+        .import         callirq
+
+        .include        "cx16.inc"
+
+; ------------------------------------------------------------------------
+
+.segment        "ONCE"
+
+initirq:
+        lda     IRQVec
+        ldx     IRQVec+1
+        sta     IRQInd+1
+        stx     IRQInd+2
+        lda     #<IRQStub
+        ldx     #>IRQStub
+        jmp     setvec
+
+; ------------------------------------------------------------------------
+
+.code
+
+doneirq:
+        lda     IRQInd+1
+        ldx     IRQInd+2
+setvec: sei
+        sta     IRQVec
+        stx     IRQVec+1
+        cli
+        rts
+
+; ------------------------------------------------------------------------
+
+.segment        "LOWCODE"
+
+IRQStub:
+        jsr     callirq                 ; Call the functions
+        jmp     IRQInd                  ; Jump to the saved IRQ vector
+
+; ------------------------------------------------------------------------
+
+.data
+
+IRQInd: jmp     $0000