STOP + RESTORE now works (bad news: works even without STOP)

Makefile

@@ -147,7 +147,7 @@ test: build/newkern_generic build/newbasic_generic
 	x64 -kernal build/newkern_generic -basic build/newbasic_generic -8 empty.d64
 
 testremote: build/newkern_generic build/newbasic_generic
-	x64 -kernal build/newkern-generic -basic build/newbasic-generic -remotemonitor
+	x64 -kernal build/newkern_generic -basic build/newbasic_generic -remotemonitor
 
 testm65: build/newc65
 	m65 -b ../mega65-core/bin/mega65r1.bit -k ../mega65-core/bin/KICKUP.M65 -R build/newc65 -4

STATUS.md

@@ -102,10 +102,10 @@ NOTE: Even the 'DONE' routines won't support features described as missing in on
 | `$FFD8`   | `SAVE`   | NOT DONE |                                                    |
 | `$FFDB`   | `SETTIM` | NOT DONE |                                                    |
 | `$FFDE`   | `RDTIM`  | NOT DONE |                                                    |
-| `$FFE1`   | `STOP`   | PARTIAL  | no connection with UDTIM                           |
+| `$FFE1`   | `STOP`   | PARTIAL  |                                                    |
 | `$FFE4`   | `GETIN`  | PARTIAL  | only some devices supported                        |
 | `$FFE7`   | `CLALL`  | DONE     |                                                    |
-| `$FFEA`   | `UDTIM`  | NOT DONE |                                                    |
+| `$FFEA`   | `UDTIM`  | NOT DONE | checking for STOP key present in SCNKEY instead    |
 | `$FFED`   | `SCREEN` | DONE     |                                                    |
 | `$FFF0`   | `PLOT`   | NOT DONE |                                                    |
 | `$FFF3`   | `IOBASE` | DONE     |                                                    |

c64/kernal/cint.s

@@ -48,9 +48,7 @@ cint_brk: ; entry for BRK and STOP+RESTORE - XXX, where should it start?
 	
 	;; Set default I/O devices (see SCINIT description at http://sta.c64.org/cbm64krnfunc.html)
 	jsr clrchn_reset
-	
+
 	;; Fallthrough/jump to screen clear routine (Compute's Mapping the 64 p215)
 	jmp clear_screen
 
-	rts
-

c64/kernal/interrupts/ea31.default_irq_handler.s

@@ -2,7 +2,8 @@
 default_irq_handler:	
 
 	jsr blink_cursor
-	jsr scan_keyboard
+	jsr JSCNKEY
+	jsr JUDTIM ; update jiffy clock
 
 	;; Acknowledge CIA interrupt and return
 	jmp clear_cia1_interrupt_flag_and_return_from_interrupt

c64/kernal/interrupts/fe47.default_nmi_handler.s

@@ -1,12 +1,25 @@
 
 default_nmi_handler:
 
-	;; XXX implement according to Compute's Mapping the Commodore 64, page 74
+	;; Implemented according to Compute's Mapping the Commodore 64, page 74
+	;; and to https://www.c64-wiki.com/wiki/Interrupt
+
+	;; Save registers, sequence according to Compute's Mapping the Commodore 64, page 73
+	pha
+	txa
+	pha
+	tya
+	pha
+
+	;; XXX: RS-232 support is not implemented
 
-	;; XXX check if the source was RESTORE key, quit if it wasn't (no RS-232 support)
 	;; XXX if cartridge present, enter it through warm start vector
-	;; XXX if stop pressed, go to default_brk_handler
 
-	inc $D020
+	;; According to C64 Wiki, if STOP key is pressed, the routine assumes warm start request
-	rti
+
+	jsr JSTOP
+	bcs +
+	jmp return_from_interrupt ; no STOP pressed
+*
+	jmp (CBINV) ; STOP + RESTORE
 

c64/kernal/interrupts/fe66.default_brk_handler.s

@@ -3,9 +3,13 @@ default_brk_handler:
 
 	;; Implemented according to Compute's Mapping the Commodore 64, pages 73-74
 
+	sei ; disable IRQs, to be sure they won't interfere
+
 	jsr JRESTOR
 	jsr JIOINIT
 	jsr CINT_BRK
 
+	cli
+
 	jmp (IBASIC_WARM_START)
 

c64/kernal/interrupts/irq_handler.s

@@ -15,6 +15,8 @@ irq_handler:
 	tya
 	pha
 
+	;; XXX check if caused by BRK, react accordingly
+
 	;; Call interrupt routine (only if initialised)
 	lda CINV
 	ora CINV+1

c64/kernal/interrupts/nmi_handler.s

@@ -1,7 +1,18 @@
 
 nmi_handler:
 
-	;; XXX provide real implementation
+	sei ;; don't allow IRQ to interfere, see https://www.c64-wiki.com/wiki/Interrupt
 
+	;; Call interrupt routine (only if initialised)
+	pha
+	lda NMINV
+	ora NMINV+1
+	bne +
+	pla
 	jmp (NMINV)
+*
+	;; Vector not initialized - call default interrupt routine
+	pla
+	jmp default_nmi_handler
+
 

c64/kernal/jumptable/ff9f.jscnkey.s

@@ -1,3 +1,3 @@
 ; Scan keyboard
 ; C64 Programmer's Reference Guide Page 273
-	jmp scan_keyboard
+	jmp SCNKEY

c64/kernal/jumptable/ffea.judtim.s

@@ -1,4 +1,4 @@
 ; $FFEA - Update jiffy clock vector
 ; (http://codebase64.org/doku.php?id=base:kernalreference)
 
-	jmp update_jiffy_clock
+	jmp UDTIM

c64/kernal/scnkey.s

@@ -69,7 +69,7 @@
 	;// Operational Variables
 	.alias MaxKeyRollover 3
 
-scan_keyboard:
+scnkey:
 
 	lda #$00
 	sta BufferQuantity
@@ -538,5 +538,3 @@ KeyCanRepeat:
 KeyRepeatWait:
 	pla
 	jmp ConsiderNextKey
-
-

c64/kernal/udtim.s

@@ -8,5 +8,5 @@
 ;; CPU registers that has to be preserved (see [RG64]): .Y
 ;;
 
-update_jiffy_clock:
+udtim:
 	rts