Disassembly:Bios - Revision history

E5frog at 20:58, 4 August 2026

2026-08-04T20:58:06Z

2026-08-03T20:45:49Z

2026-08-03T20:33:13Z

2026-08-03T19:56:30Z

2026-08-03T19:32:33Z

2026-08-03T18:35:28Z

2026-08-03T17:59:05Z

2026-08-03T17:36:15Z

2020-08-16T09:33:46Z

2020-08-16T09:24:45Z

@@ Line 168: / Line 168: @@
+;
 ; NOTES:
-; Needs r31 (O37) to have b0 and b7 clear or you'll get a black bar from row 50
+; Needs r31 (O37) to have data in either b0 and/or b7 or you'll get a black bar from row 50
 ; Uses r52 (O64) for ISAR values
 ; Has to have a valid stack pointer in r59 (O73)
@@ Line 183: / Line 183: @@
 ; Code to use the routine (check r31 as well):
 ;	li	{color code}
 ;	lr	3, A

@@ Line 166: / Line 166: @@
 ; clears screen using the drawchar routine, one character at the time
 ; it covers the entire VRAM area (0,0) to (127,63), writes line 0 twice
-; NOTE:
-; it also uses r31 (O37), b0 and b7 needs to be 0 or you'll get a black bar
+; NOTES:
 ; load register 3 (lr 3,A) with color value
 ; lt.grey:  $D4, $D6, $DC or $DE

@@ Line 163: / Line 163: @@
 ;==============;
+; all pixels are written to background, palette is set in r3
-; clears the screen to a color and palette specified in r3
+; clears screen using the drawchar routine, one character at the time
-; it clears screen using the drawchar routine, one character at the time
+; it covers the entire VRAM area (0,0) to (127,63), writes line 0 twice
-; it covers the area from (0,0) to (127,63)
+; NOTE:
-; it uses r31 (O37), b0 and b7 needs to be 0 or you'll get a black bar
+; it also uses r31 (O37), b0 and b7 needs to be 0 or you'll get a black bar
-	; clear screen to gray
-;	li	$d6
+; load register 3 (lr 3,A) with color value
-	; clear screen to green
+; lt.grey:  $D4, $D6, $DC or $DE
-;	li	$c0
+; lt.green: $C0, $C2, $C8 or $CA
-	; clear screen to b/w
+; lt.blue:  $91, $93, $99 or $9B
-;	li	$21
+; black/w:  $21, $23, $29 or $2B
-	; clear screen to blue
-;	li	$93
+; Code to use the routine (check r31 as well):
 ;	lr	3, A
 ;	pi	clrscrn

@@ Line 167: / Line 167: @@
 ; it clears screen using the drawchar routine, one character at the time
 ; it covers the area from (0,0) to (127,63)
-; it uses r31 (O37)
+; it uses r31 (O37), b0 and b7 needs to be 0 or you'll get a black bar
 	; clear screen to gray

@@ Line 163: / Line 163: @@
 ;==============;
 ; clears the screen to a color and palette specified in r3
 	; clear screen to gray

@@ Line 211: / Line 211: @@
 	lr	A, 2
 	ci	$30
-	bc	csloop2
+	bc	clrscrn.loop2
 	lis	0
 	lr	3, A

@@ Line 1,411: / Line 1,411: @@
                  INC                      ; 0749 1f
                  LR   $1,A                ; 074a 51
                  LIS  $4                  ; 074b 74
                  LR   $8,A                ; 074c 58
 A074d:          DS   $8                  ; 074d 38
-                 BNZ  A074d            ; 074e 94 fe
+                 BNZ  A074d               ; 074e 94 fe
                  DS   $5                  ; 0750 35
-                 BNZ  A0731            ; 0751 94 df
+                 BNZ  A0731               ; 0751 94 df
                  LR   A,$2                ; 0753 42
                  INC                      ; 0754 1f

@@ Line 1,599: / Line 1,599: @@
 	.byte	%00000000
-				db $08,$08,$08,$08,$08	;|
+	; Hockey (Tennis) players
-				db $20,$20,$20,$20,$20	;|
+	.byte	%00001000
-				db $10,$10,$20,$40,$40	; rest are slanted lines
+	.byte	%00001000
-				db $08,$10,$20,$40,$80
+	.byte	%00001000
-				db $00,$18,$20,$C0,$00
+	.byte	%00001000
-				db $00,$C0,$20,$18,$00
+	.byte	%00001000
 </pre>

@@ Line 165: / Line 165: @@
 ; clears the screen to a color and palette specified in r3
-clrscrn:
+	; clear screen to gray
 	; save return address
 	lr	K, P