spectrumswearingxylophone/xylo.asm

org 51000

counter EQU inc_counter + 1
attrs EQU #5800
xylo EQU attrs + 40

zero_counter:
	xor a

set_counter:
	ld (counter), a

read_keyboard:
	ld a, #f7
	in a, (#fe)
	rra
	jr nc, key_1
	rra
	jr nc, key_2
	rra
	jr nc, key_3
	rra
	jr nc, key_4
	rra
	jr c, read_keyboard

key_5:
	ld de, #040C
	jr invoke

key_2:
	ld de, #0103
	jr invoke

key_3:
	ld de, #0206
	jr invoke

key_4:
	ld de, #0309
	jr invoke

key_1:
	ld de, #0000
invoke:
	push de
	call highlight_key
	ld a, (counter)
	add a, d
	call play
	pop de
	call highlight_key

inc_counter:
	ld a, 0		;This value will be modified by the running code
	add a, 5
	cp 25
	jr nz, set_counter
	jr zero_counter

highlight_key:
	ld hl, xylo
	push de
	ld d, 0
	add hl, de
	ld e, 30
	ld a, (hl)
	xor %01000000
	ld b, 15
highlight_block:
	ld (hl), a
	inc hl
	ld (hl), a
	inc hl
	ld (hl), a
	add hl, de
	djnz highlight_block
	pop de
	ret

INCLUDE "sample.asm"
Initial commit 2024-10-21 08:30:19 +00:00			`org 51000`

Self modifying code to save 2 bytes 2024-10-21 16:23:30 +00:00			`counter EQU inc_counter + 1`
Save a few t-states in loop and clean up numeric literals 2024-10-22 11:56:45 +00:00			`attrs EQU #5800`
Highlight keys when pressed 2024-10-21 18:49:02 +00:00			`xylo EQU attrs + 40`
Self modifying code to save 2 bytes 2024-10-21 16:23:30 +00:00
Initial commit 2024-10-21 08:30:19 +00:00			`zero_counter:`
			`xor a`

			`set_counter:`
			`ld (counter), a`

			`read_keyboard:`
Save a few t-states in loop and clean up numeric literals 2024-10-22 11:56:45 +00:00			`ld a, #f7`
			`in a, (#fe)`
Shave a few bytes by switch srl a to rra 2024-10-21 14:51:52 +00:00			`rra`
Initial commit 2024-10-21 08:30:19 +00:00			`jr nc, key_1`
Shave a few bytes by switch srl a to rra 2024-10-21 14:51:52 +00:00			`rra`
Initial commit 2024-10-21 08:30:19 +00:00			`jr nc, key_2`
Shave a few bytes by switch srl a to rra 2024-10-21 14:51:52 +00:00			`rra`
Initial commit 2024-10-21 08:30:19 +00:00			`jr nc, key_3`
Shave a few bytes by switch srl a to rra 2024-10-21 14:51:52 +00:00			`rra`
Initial commit 2024-10-21 08:30:19 +00:00			`jr nc, key_4`
Shave a few bytes by switch srl a to rra 2024-10-21 14:51:52 +00:00			`rra`
Reorder key scan to permit fall through to save a couple of bytes 2024-10-22 11:08:09 +00:00			`jr c, read_keyboard`
Initial commit 2024-10-21 08:30:19 +00:00
Reorder key scan to permit fall through to save a couple of bytes 2024-10-22 11:08:09 +00:00			`key_5:`
Save a few t-states in loop and clean up numeric literals 2024-10-22 11:56:45 +00:00			`ld de, #040C`
Reduce repeated code in key selection routine 2024-10-21 22:18:21 +00:00			`jr invoke`
Initial commit 2024-10-21 08:30:19 +00:00
			`key_2:`
Save a few t-states in loop and clean up numeric literals 2024-10-22 11:56:45 +00:00			`ld de, #0103`
Reduce repeated code in key selection routine 2024-10-21 22:18:21 +00:00			`jr invoke`
Initial commit 2024-10-21 08:30:19 +00:00
			`key_3:`
Save a few t-states in loop and clean up numeric literals 2024-10-22 11:56:45 +00:00			`ld de, #0206`
Reduce repeated code in key selection routine 2024-10-21 22:18:21 +00:00			`jr invoke`
Initial commit 2024-10-21 08:30:19 +00:00
			`key_4:`
Save a few t-states in loop and clean up numeric literals 2024-10-22 11:56:45 +00:00			`ld de, #0309`
Reduce repeated code in key selection routine 2024-10-21 22:18:21 +00:00			`jr invoke`
Initial commit 2024-10-21 08:30:19 +00:00
Reorder key scan to permit fall through to save a couple of bytes 2024-10-22 11:08:09 +00:00			`key_1:`
Save a few t-states in loop and clean up numeric literals 2024-10-22 11:56:45 +00:00			`ld de, #0000`
Reduce repeated code in key selection routine 2024-10-21 22:18:21 +00:00			`invoke:`
			`push de`
Highlight keys when pressed 2024-10-21 18:49:02 +00:00			`call highlight_key`
Initial commit 2024-10-21 08:30:19 +00:00			`ld a, (counter)`
Reduce repeated code in key selection routine 2024-10-21 22:18:21 +00:00			`add a, d`
Initial commit 2024-10-21 08:30:19 +00:00			`call play`
Reduce repeated code in key selection routine 2024-10-21 22:18:21 +00:00			`pop de`
Highlight keys when pressed 2024-10-21 18:49:02 +00:00			`call highlight_key`
Initial commit 2024-10-21 08:30:19 +00:00
			`inc_counter:`
Self modifying code to save 2 bytes 2024-10-21 16:23:30 +00:00			`ld a, 0 ;This value will be modified by the running code`
Initial commit 2024-10-21 08:30:19 +00:00			`add a, 5`
			`cp 25`
			`jr nz, set_counter`
Improve key highlight routine to save a few bytes 2024-10-21 21:53:06 +00:00			`jr zero_counter`
Highlight keys when pressed 2024-10-21 18:49:02 +00:00
			`highlight_key:`
			`ld hl, xylo`
Reduce repeated code in key selection routine 2024-10-21 22:18:21 +00:00			`push de`
Improve key highlight routine to save a few bytes 2024-10-21 21:53:06 +00:00			`ld d, 0`
			`add hl, de`
Reduce repeated code in key selection routine 2024-10-21 22:18:21 +00:00			`ld e, 30`
Highlight keys when pressed 2024-10-21 18:49:02 +00:00			`ld a, (hl)`
			`xor %01000000`
Save a few t-states in loop and clean up numeric literals 2024-10-22 11:56:45 +00:00			`ld b, 15`
			`highlight_block:`
Highlight keys when pressed 2024-10-21 18:49:02 +00:00			`ld (hl), a`
			`inc hl`
Reduce repeated code in key selection routine 2024-10-21 22:18:21 +00:00			`ld (hl), a`
			`inc hl`
			`ld (hl), a`
Improve key highlight routine to save a few bytes 2024-10-21 21:53:06 +00:00			`add hl, de`
Reduce repeated code in key selection routine 2024-10-21 22:18:21 +00:00			`djnz highlight_block`
			`pop de`
Highlight keys when pressed 2024-10-21 18:49:02 +00:00			`ret`
Initial commit 2024-10-21 08:30:19 +00:00
			`INCLUDE "sample.asm"`