JimmyDansbo’s gists

JimmyDansbo / vmem_copy.asm

Created December 23, 2025 06:45

Test of copying between VERA data0 and data1 where address of data0 is altered between copy's

	!cpu w65c02
	!macro SYS_LINE .main {
	*=$801
	!word .next_line ; Pointer to next BASIC line
	!word $000A ; Line number $000A = 10
	!byte $9E ; SYS BASIC token
	!byte 48+(.main/1000)%10 ; Address where ASM starts in PETSCII
	!byte 48+(.main/100)%10
	!byte 48+(.main/10)%10
	!byte 48+(.main/1)%10

JimmyDansbo / build_commander_x16_web_emulator.sh

Created December 18, 2025 08:36

	# Build X16 emulator webassembly:

	# Install emscripten:
	# https://emscripten.org/docs/getting_started/downloads.html

	git clone https://github.com/emscripten-core/emsdk.git
	cd emsdk

	# Fetch the latest version of the emsdk (not needed the first time you clone)
	git pull

JimmyDansbo / perle.html

Created October 2, 2025 20:08

HTML/Javascript page to create patterns for sewing Hama pearls

	<html>
	<head>
	<meta charset="UTF-8">
	<title>Perler på snor</title>
	<script>
	let chosencolor='white';
	let colorid=1;

	function change_chosen_color(color) {
	chosencolor=color;

JimmyDansbo / x16speed.asm

Last active February 7, 2025 22:02

Small program to show the difference in speed on the Commander X16 with different clock speeds. Result is the amount of increments that were possible within VERA 60Hz interrupt cycle. Build with cl65 -t cx16 -o X16SPEED.PRG x16speed.asm

	.segment "STARTUP"
	.segment "INIT"
	.segment "ONCE"
	.segment "CODE"

	IRQVECTOR = $0314
	VERA_IEN = $9F26
	VERA_ISR = $9F27
	CHROUT = $FFD2

JimmyDansbo / helloworld_vera_rom_acme.asm

Created December 26, 2020 10:11

Hello World as a Commander X16 ROM image

	!cpu 65c02
	VERA_ADDR_L = $9F20
	VERA_ADDR_M = $9F21
	VERA_ADDR_H = $9F22
	VERA_DATA0 = $9F23
	VERA_CTRL = $9F25
	VERA_DC_VIDEO = $9F29
	VERA_DC_HSCALE = $9F2A
	VERA_DC_VSCALE = $9F2B
	VERA_DC_HSTOP = $9F2A

JimmyDansbo / verahello.asm

Created December 19, 2020 11:17

Example of writing text to screen using VERA on Commander X16

	!cpu 65c02

	; BASIC program ("10 SYS $0810")
	*=$0801
	!word $080C ; Pointer to next BASIC line
	!word $000A ; Line number $000A = 10
	!byte $9E ; SYS BASIC token
	!pet " $810",0 ; Address where ASM starts
	!word $0000 ; EOF BASIC program
	*=$0810

JimmyDansbo / rnd.asm

Last active December 19, 2020 10:35

Random number between 0 and 9

	*=$0801
	!word $080C ; Pointer to next BASIC line
	!word $000A ; Line number $000A = 10
	!byte $9E ; SYS BASIC token
	!pet " $810",0 ; Address where ASM starts
	!word $0000 ; EOF BASIC program
	*=$0810

	CHROUT = $FFD2
	SEED = $9F64 ; VIA timer low-byte

JimmyDansbo / jd-4bpp-bmp-directly-to-vram.asm

Last active October 18, 2022 08:05

Example of loading af 4bpp bitmap directly to VRAM by using the KERNAL API calls - R38

	*=$0801
	!byte $0C,$08,$0A,$00,$9E,' ','2','0','6','4',$00,$00,$00
	*=$0810

	VERA_BASE = $9F20
	VERA_ADDR_L = VERA_BASE
	VERA_ADDR_M = VERA_BASE+1
	VERA_ADDR_H = VERA_BASE+2
	VERA_DATA0 = VERA_BASE+3
	VERA_DC = VERA_BASE+9

JimmyDansbo / jd-4bit-demo.asm

Created January 21, 2020 06:28

Short example of loading 4bpp picture into VERA

	*=$0801
	!byte $0C,$08,$0A,$00,$9E,' ','2','0','6','4',$00,$00,$00
	*=$0810

	VERA_BASE = $9F20
	VERA_ADDR_LOW = VERA_BASE+0
	VERA_ADDR_HIGH = VERA_BASE+1
	VERA_ADDR_BANK = VERA_BASE+2
	VERA_DATA0 = VERA_BASE+3
	VERA_DATA1 = VERA_BASE+4

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