implemented VECTOR routine

c64/kernal/vector.s

@@ -1,6 +1,80 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+; Functions defined on pp272-273 of C64 Programmers Reference Guide
+
+restor:
+
+	clc ;; clear carry - for writing to system table
+	ldx #<vector_defaults
+	ldy #>vector_defaults
+
+	;; FALLTHROUGH
+
 vector:
 
-	;; XXX adapt restor when this is implemented
+.scope
 
+	;; Temporary storage location
+	.alias _caller_arr_ptr CMP0
+
+	;; According to 'Compute's Mapping the Commodore 64' page 237,
+	;; the CBM implementation does not disable IRQs - yet, the
+	;; 'C64 Programmers Reference Guide' does not contain such
+	;; warning and does not mention any preparations needed, so...
+	;; better safe than sorry, disable the IRQ for the duration
+	;; of vector manipulation
+	php
+	cli
+	
+	;; Prepare the user data pointer
+	stx _caller_arr_ptr + 0
+	sty _caller_arr_ptr + 1
+	
+	;; Select routine variant - store or restore vectors
+	ldy #$1F
+	bcc vector_restore
+	
+	;; FALLTHROUGH
+	
+vector_store:
+*
+	lda CINV, y
+	sta (_caller_arr_ptr), y
+	dey
+	bpl -
+	
+	;; Restore status register (IRQ) before return
+	plp
 	rts
+	
+vector_restore:
+*
+	lda (_caller_arr_ptr), y
+	sta CINV, y
+	dey
+	bpl -
+
+	;; Restore status register (IRQ) before return
+	plp
+	rts
+
+.scend
+
+	;; XXX below we have quite a lot of data... should we decouple them?
+
+vector_defaults:
+	.word $0000    ;; CINV     XXX implement this
+	.word $0000    ;; CBINV    XXX implement this
+	.word $0000    ;; NMINV    XXX implement this
+	
+	.word open     ;; IOPEN
+	.word close    ;; ICLOSE
+	.word chkin    ;; ICHKIN
+	.word chkout   ;; ICKOUT
+	.word clrchn   ;; ICLRCH
+	.word chrin    ;; IBASIN
+	.word chrout   ;; IBASOUT
+	.word stop     ;; ISTOP
+	.word getin    ;; IGETIN
+	.word clall    ;; ICLALL
+	.word $0000    ;; USRCMD   XXX implement this
+	.word load     ;; ILOAD
+	.word save     ;; ISAVE