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Opcode

E5frog — Fri, 07 Aug 2026 17:02:44 GMT

Snippet:KStack

E5frog — Wed, 05 Aug 2026 18:25:46 GMT

Disassembly:Videocart 4

E5frog — Wed, 05 Aug 2026 18:20:52 GMT

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File:L0E60 bitmap 8x24 scale24.png

E5frog — Wed, 05 Aug 2026 18:07:38 GMT

E5frog uploaded File:L0E60 bitmap 8x24 scale24.png

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File:L0DE0 bitmap 8x128 scale16.png

E5frog — Wed, 05 Aug 2026 18:03:00 GMT

E5frog uploaded File:L0DE0 bitmap 8x128 scale16.png

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Snippet:KStack

E5frog — Tue, 04 Aug 2026 22:44:31 GMT

Snippet:KStack

E5frog — Tue, 04 Aug 2026 22:43:21 GMT

Created page with "<pre> ;=========================================================================== ; KStack Functions ;========================================================================..."

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<pre>
;===========================================================================
; KStack Functions
;===========================================================================
; the K stack implements a stack using the registers. it uses r63 as a stack
; pointer that holds the register number of the top of the stack, starting
; at r57 and working down. when called, K is pushed to the first two
; registers on the stack, and the pointer is increased.
;
; at startup, the stack pointer (r63) should be set to 62 ($3E)

;---------------------------------------------------------------------------
; KStack Push
;---------------------------------------------------------------------------
; pushes register K onto the stack using r63 as the stack pointer
; destroys ISAR

kstack.push:
; get the top of the stack
lisu 7
lisl 7 ; r63, stack pointer
lr A, S
lr IS, A ; load the referenced register
; push K onto the stack
lr A, Ku
lr S, A ; push high byte of K
lr A, IS
ai $ff ; decrease ISAR
lr IS, A
lr A, Kl
lr S, A ; push low byte of K
; adjust the stack pointer
lr A, IS
ai $ff ; decrease ISAR
lisu 7
lisl 7
lr S, A ; store the adjusted stack pointer in r63

; return from the subroutine
pop

;---------------------------------------------------------------------------
; KStack Pop
;---------------------------------------------------------------------------
; pops register K from the stack using r63 as the stack pointer
; destroys ISAR

kstack.pop:
; retrieve K from the stack
lisu 7
lisl 7
lr A, S ; load the stack pointer into A
inc ; increment the pointer
lr IS, A ; and set the ISAR
lr A, S
lr Kl, A ; load lower byte of K
lr A, IS
inc ; increase ISAR
lr IS, A
lr A, S
lr Ku, A ; load upper byte of K
; adjust the stack pointer
lr A, IS
lisu 7
lisl 7
lr S, A ; store the adjusted stack pointer in r63

; return from the subroutine
pop
</pre>

Subroutines

E5frog — Tue, 04 Aug 2026 22:41:49 GMT

Disassembly:Democart 2

E5frog — Tue, 04 Aug 2026 22:34:28 GMT

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Disassembly:Bios

E5frog — Tue, 04 Aug 2026 20:58:06 GMT

Disassembly:Democart 2

E5frog — Tue, 04 Aug 2026 20:27:43 GMT

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Disassembly:Bios

E5frog — Mon, 03 Aug 2026 20:45:49 GMT

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Main Page

E5frog — Sat, 01 Aug 2026 05:51:13 GMT

‎Getting Started

File:Devel MESSUI0235.7z

E5frog — Sat, 01 Aug 2026 05:50:04 GMT

E5frog uploaded File:Devel MESSUI0235.7z DASM assembler, the MESS emulator and an early version of Pac-Man as a sample game.

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DASM assembler, the MESS emulator and an early version of Pac-Man as a sample game.

Snippet:Multiblit

E5frog — Sun, 26 Jul 2026 17:47:10 GMT

Snippet:Blit

E5frog — Thu, 16 Jul 2026 23:06:32 GMT

@@ Line 136: / Line 136: @@
 | LM || 1 || 2.5 || A &larr; ((DC0))<br>DC0 &larr; DC0 + 1 || %00010110 || $16 ||- ||- ||- ||- || L <br> S || 2 <br> 0
 |-
-| ST || 1 || 2.5 || DC0 &larr; (A)<br>DC0 &larr; DC0 + 1 || %00010111 || $17 ||- ||- ||- ||- || L <br> S || 5 <br> 0
+| ST || 1 || 2.5 || ((DC0)) &larr; (A)<br>DC0 &larr; DC0 + 1 || %00010111 || $17 ||- ||- ||- ||- || L <br> S || 5 <br> 0
 |-
 | COM || 1 || 1 || A &larr; (A)&oplus;$FF<br>[invert/complement]|| %00011000 || $18 || 0 || X || 0 || X || S || 0
@@ Line 194: / Line 194: @@
 | LR HL, A || 1 || 1 || HL &larr; (A) || %01011011 || $5B ||- ||- ||- ||- || S || 0
 |-
-| LISU i || 1 || 1 || ISARU &larr; i || %01100xxx || $6x ||- ||- ||- ||- || S || 0
+| LISU i || 1 || 1 || ISARU &larr; i || %01100xxx || $60-$67 ||- ||- ||- ||- || S || 0
 |-
-| LISL i || 1 || 1 || ISARL &larr; i || %01101xxx || $6x ||- ||- ||- ||- || S || 0
+| LISL i || 1 || 1 || ISARL &larr; i || %01101xxx || $68-$6F ||- ||- ||- ||- || S || 0
 |-
 | CLR || 1 || 1 || A&larr;0 || %01110000 || $70 ||- ||- ||- ||- || S || 0

@@ Line 64: / Line 64: @@
 By using PUSHK/POPK, you can have more than 2 levels of subroutine calls. However, a lot of overhead is added to the code by manipulating the stack. When inside a pushk/popk subroutine it's still possible to use plain pi/pop as it only affects PC0 and PC1. Whenever calling a subroutine one level deep, it's best to use the PI/POP combination; for two levels of subroutines, it's best to use the second example above. If using the K register in a subroutine only simple PI/POP is usable to get there, not to destroy contents of K.
 <pre>
@@ Line 88: / Line 90: @@
 ; modifies: r7
 pushk:
-	; backup the ISAR
+		lr	A, IS				; backup ISAR in r7
-	lr	A, IS
+		lr	7,A
-	lr	7, A
+		lisu	7				; get the top of the stack
+		lisl	3				; r59, stack pointer
-	; get the top of the stack
+		lr	A,S
-	lisu	7
+		lr	IS, A				; load the referenced register
-	lisl	3			; r59, stack pointer
+		lr	A,KU
-	lr	A, S
+		lr	I,A				; push high byte of K
-	lr	IS, A			; load the referenced register
+		lr	A,KL
-	; push K onto the stack
+		lr	I,A				; push low byte of K
-	lr	A, Ku
+		lr	A,IS
-	lr	S, A			; push high byte of K
+		lisu	7
-	lr	A, IS
+		lisl	3
-	inc
+		lr	S,A				; save the register number to the stack pointer
-	lr	IS, A			; increase ISAR (they could've used lr I, A)
+		lr	A,7				; restore the ISAR
-	lr	A, Kl
+		lr	IS,A
-	lr	S, A			; push low byte of K
+		pop
 ;--------;
@@ Line 131: / Line 119: @@
 ; modifies: r7
 popk:
-	; backup the ISAR
+		lr	A,IS				; backup ISAR in r7
-	lr	A, IS
+		lr	7,A
-	lr	7, A
+		lisu	7				; r59, stack pointer
+		lisl	3
-	; retrieve K from the stack
+		lr	A,S				; A = stack pointer, points to next free
-	lisu	7
+		ai	$ff				; A = last pushed byte, KL
-	lisl	3
+		lr	IS,A				; ISAR -> KL
-	lr	A, S			; load the stack pointer
+		lr	A,D				; read KL, then ISAR -> KU
-	ai	$ff			; "subtract" 1 to get the first register on the stack
+		lr	KL,A
-	lr	IS, A			; set the ISAR to this register
+		lr	A,S				; read KU
-	lr	A, S
+		lr	KU,A
-	lr	Kl, A			; load lower byte of K
+		lr	A,IS				; ISAR now points to new stack pointer
-	lr	A, IS
+		lisu	7
-	ai	$ff			; get previous register (they could've used lr A, D)
+		lisl	3
-	lr	IS, A
+		lr	S,A				; store new stack pointer in r59
-	lr	A, S
+		lr	A,7				; restore original ISAR
-	lr	Ku, A			; load upper byte of K
+		lr	IS,A
-	; adjust pointer to the top of the stack
+		pop
 ;===================;

@@ 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 116: / Line 116: @@
 == Getting Started ==
-If you'd like to get started programming games for the Channel F, try downloading the <br>[https://channelf.se/veswiki/images/9/99/Devel.7z Development Pack (.7z, 2.8 MB)]. <br>It includes the DASM assembler, the MESS emulator and an early version of Pac-Man as a sample game that you can edit, compile and test. Just unpack it, preferably directly on root of your hard drive and doubleclick '''..\devel\games\pacman\!compile+run.bat''' or the '''!run.bat''' in the same directory and it should start right up. Press Esc to leave the debugger. <br> It has been tested (and is working) on Windows XP Home SP3.<br><br>
+If you'd like to get started programming games for the Channel F, try downloading the <br>[https://channelf.se/veswiki/images/a/ac/Devel_MESSUI0235.7z Development Pack (.7z, 18.9 MiB)]. <br>It includes the DASM assembler, the MESS emulator and an early version of Pac-Man as a sample game that you can edit, compile and test. Just unpack it, preferably directly on root of your hard drive and doubleclick '''..\devel\games\pacman\!compile+run.bat''' or the '''!run.bat''' in the same directory and it should start right up. Press Esc to leave the debugger. <br> It has been tested (and is working) on Windows XP Home SP3.<br><br>
 Here's a tutorial that might be helpful:
 [[Tutorial:Beginner%27s_Guide_to_the_Channel_F | Beginner's guide to the Channel F]]

@@ Line 79: / Line 79: @@
 ; Multiblit Function ;
 ;--------------------;
+;
 ; This function blits a 4-color graphic based on parameters set
@@ Line 106: / Line 102: @@
 multiblit:
 	clr
 	com
@@ Line 197: / Line 184: @@
 </pre>
-<em>Note: the adjustment of x and y in '''multiblit''' are to allow the coodinates 0, 0 to access the upper left pixel </em>visible to the screen in MESS<em>, not to VRAM, which expands four pixels above and to the left of that position.</em>
+<em>You need to start at (4,4) for the upper left corner in MESS.</em>

@@ Line 4: / Line 4: @@
 ;===========================================================================
 ; the K stack implements a stack using the registers. it uses r63 as a stack
-; pointer that holds the register number of the top of the stack, starting
+; pointer that holds the register number of the top of the stack.
-; at r57 and working down. when called, K is pushed to the first two
+; When called, K is pushed to the first two registers on the stack, and the
-; registers on the stack, and the pointer is increased.
+; pointer is increased.
+;
 ; at startup, the stack pointer (r63) should be set to 62 ($3E)
@@ Line 14: / Line 14: @@
 ;---------------------------------------------------------------------------
 ; pushes register K onto the stack using r63 as the stack pointer
-; destroys ISAR
+; destroys ISAR data
-kstack.push:
+pushk:
-	; get the top of the stack
+		lisu	7				; get the top of the stack
-	lisu	7
+		lisl	7				; r63, stack pointer
-	lisl	7			; r63, stack pointer
+		lr	A,S
-	lr	A, S
+		lr	IS, A				; load the referenced register
-	lr	IS, A			; load the referenced register
+		lr	A,KU
-	; push K onto the stack
+		lr	I,A				; push high byte of K
-	lr	A, Ku
+		lr	A,KL
-	lr	D, A			; push high byte of K
+		lr	I,A				; push low byte of K
-	lr	A, Kl
+		lr	A,IS
-	lr	S, A			; push low byte of K
+		lisu	7
-	; adjust the stack pointer
+		lisl	3
-	lr	A, IS
+		lr	S,A				; save the register number to the stack pointer
-	ai	$ff			; decrease ISAR
+		pop
 ;---------------------------------------------------------------------------
@@ Line 43: / Line 37: @@
 ; destroys ISAR
-kstack.pop:
+popk:
-	; retrieve K from the stack
+		lisu	7				; r63, stack pointer
-	lisu	7
+		lisl	7
-	lisl	7
+		lr	A,S				; A = stack pointer, points to next free
-	lr	A, S			; load the stack pointer into A
+		ai	$ff				; A = last pushed byte, KL
-	inc				; increment the pointer
+		lr	IS,A				; ISAR -> KL
-	lr	IS, A			; and set the ISAR
+		lr	A,D				; read KL, then ISAR -> KU
-	lr	A, I
+		lr	KL,A
-	lr	Kl, A			; load lower byte of K
+		lr	A,S				; read KU
-	lr	A, S
+		lr	KU,A
-	lr	Ku, A			; load upper byte of K
+		lr	A,IS				; ISAR now points to new stack pointer
-	; adjust the stack pointer
+		lisu	7
-	lr	A, IS
+		lisl	3
-	lisu	7
+		lr	S,A				; store new stack pointer in r59
-	lisl	7
+		pop
 </pre>

@@ Line 65: / Line 65: @@
+;
 ; DC = pointer to graphics
 blit: