added PAL/NTSC detection

STATUS.md

@@ -70,7 +70,7 @@ NOTE: Even the 'DONE' routines won't support features described as missing in on
 
 | Address   | Name     | Status   |  Remarks                                           |
 | --------- | :------- | :------: | :------------------------------------------------: |
-| `$FF81`   | `CINT`   | PARTIAL  | at least PAL/NTSC detection is missing             |
+| `$FF81`   | `CINT`   | DONE     |                                                    |
 | `$FF84`   | `IOINIT` | PARTIAL  | at least SID volume handling is missing            |
 | `$FF87`   | `RAMTAS` | DONE     |                                                    |
 | `$FF8A`   | `RESTOR` | DONE     |                                                    |

c64/basic/basic_cold_start.s

@@ -17,6 +17,14 @@ startup_banner:
 
 	`TARGET_HOOK_BANNER
 
+	;; Print PAL/NTSC
+	ldx #30 ; NTSC
+	lda PALNTSC
+	beq +
+	ldx #31 ; PAL
+*
+	jsr print_packed_message
+
 	;; Work out free bytes, and display
 	jsr basic_do_new
 	lda basic_top_of_memory_ptr+0
@@ -26,7 +34,7 @@ startup_banner:
 	lda basic_top_of_memory_ptr+1
 	sbc basic_end_of_text_ptr+1
 
-	jsr print_integer	
+	jsr print_integer
 
 	lda #$20
 	jsr JCHROUT
@@ -37,8 +45,8 @@ startup_banner:
 
 	;; jump into warm start loop
 	jmp basic_warm_start
-	
-	
+
+
 startup_message:
 	;; Clear the screen
 	.byte $93

c64/kernal/cint.s

@@ -14,7 +14,32 @@ cint:
 cint_brk: ; entry for BRK and STOP+RESTORE - XXX, where should it start?
 
 	jsr setup_vicii
-	
+
+	;; Detect video system (PAL/NTSC), use Graham's method, as it's short and reliable
+	;; see here: https://codebase64.org/doku.php?id=base:detect_pal_ntsc
+
+cint_w0:
+	lda VIC_RASTER
+cint_w1:
+	cmp VIC_RASTER
+    beq cint_w1
+    bmi cint_w0
+
+	;; Result in A, if no interrupt happened during the test:
+	;; #$37 -> 312 rasterlines, PAL,  VIC 6569
+	;; #$06 -> 263 rasterlines, NTSC, VIC 6567R8
+	;; #$05 -> 262 rasterlines, NTSC, VIC 6567R56A
+
+	cmp #$07
+	bcs cint_pal
+cint_ntsc:
+	lda #$00
+	beq +
+cint_pal:
+	lda #$01
+*
+	sta PALNTSC
+
 	;; Initialise cursor blink flags  (Compute's Mapping the 64 p215)
 	lda #$00
 	sta cursor_blink_disable
@@ -51,4 +76,3 @@ cint_brk: ; entry for BRK and STOP+RESTORE - XXX, where should it start?
 
 	;; Fallthrough/jump to screen clear routine (Compute's Mapping the 64 p215)
 	jmp clear_screen
-

src/compress_text.c

@@ -159,15 +159,20 @@ char *error_list[]={
   "LOAD",                  // https://www.discogs.com/Gimmik-Load-Error/release/482462
   // Non-error messages
   "READY.\r", // #29       // https://www.ibm.com/support/knowledgecenter/zosbasics/com.ibm.zos.zconcepts/zconc_whatistsonative.htm https://github.com/stefanhaustein/expressionparser
-  "LOADING", // #30              // https://community.tibco.com/wiki/how-show-loading-prompt-when-reloading-external-data
-  "VERIFYING",             // https://discussions.apple.com/thread/8087203
-  "SAVING",
+  "NTSC, ", // #30
+  "PAL, ", // #31
+  "", // unused for now
   "ERROR", // #33            // Simply the word error that is attached to the other parts of messages https://fjkraan.home.xs4all.nl/comp/apple2faq/app2asoftfaq.html
-  "BYTES FREE.\r\r", // #34 // https://github.com/stefanhaustein/expressionparser
+  "BYTES FREE\r\r", // #34 // https://github.com/stefanhaustein/expressionparser
   "MEMORY CORRUPT", // #35
   "NOT IMPLEMENTED", // #36
   NULL};
 
+// XXX: create separate list for Kernal  
+// "LOADING", // #30              // https://community.tibco.com/wiki/how-show-loading-prompt-when-reloading-external-data
+// "VERIFYING",             // https://discussions.apple.com/thread/8087203
+// "SAVING",
+
 // Token $FF is end of message, so we can have only 255 unique words
 #define MAX_WORDS 255
 char *words[MAX_WORDS];