Micro Adlib player in Assembly

Last Updated or created 2023-10-05

Plays RAW adlib songs in 100 lines of code … kindda

Using information from here:
https://moddingwiki.shikadi.net/wiki/RAW_Format_(Adlib)

And using fasm to compile I can play captured raw songs.

But something is still off ?!?

It sounds a little different, and I need to implement a better timer routine. (Below my version and opencubicplayer)

This is a test for my bootloader, playing music from my bootblock!

CODE

use16
org 0x100

ctrlreg=0388h
datareg=0389h


mainloop:
	; set speed (Byte 8,9 from the raw file)
	mov ax,[tune+8]
	mov [clockspeed],ax
	; call player
	call rawreg
	; wait 0.5 sec for exit
	mov bx,6
	call waitmore
	jmp exit

rawreg:
	mov bx,tune+0ah		; start of song at offset ah

; order registerdata, register!
; Are there more control codes? ???

lraw:
	mov cx,[bx]
; reg = 2 - check data
	cmp ch,2
	je checkreg2
; reg = 0 - cyclewait
	cmp ch,0
	je cyclewait
; data = FFFF - end song - end play routine
	cmp cx,0ffffh
	jne skipr
	ret

cyclewait:		; waits cl times waitroutine
cylloop:	
	call waitlong
	dec cl
	jnz cylloop
	inc bx
	inc bx
	jmp lraw

checkreg2:
; check low opl
	cmp cl,1
	jne checkh
	mov ch,0
	mov [highlow],ch
	jmp incandret
checkh:
; check high opl
	cmp cl,2
	jne check00
	mov ch,1
	mov [highlow],ch
	jmp incandret
check00:
; set new speed
	cmp cl,0
	jne incandret
	inc bx
	inc bx
	mov ax,[bx]
	mov [clockspeed],ax
	
incandret:
; next double byte in the song please
	inc bx     
	inc bx     
	jmp lraw

skipr:
; sends data to the control and data registers
	mov dx,ctrlreg
	mov al,[highlow]
	cmp al,0
	je regokay
	inc dx
	inc dx
regokay:
	mov al,ch
	out dx,al
;	call waitshort ; not needed for newer adlib cards
	mov dx,datareg
	mov al,[highlow]
	cmp al,0
	je regokay2
	inc dx
	inc dx
regokay2:
	mov al,cl
	out dx,al
	call waitlong
	inc bx
	inc bx
	jmp lraw

waitshort:
	push ax
	push cx
	push dx
	mov cx, 0      ;HIGH WORD.
	mov dx, 010h ;LOW WORD.
	mov ah, 86h    ;WAIT.
	int 15h
	pop dx
	pop cx
	pop ax
	ret

waitlong:
	push bx
	push ax
	push cx
	push dx
	mov cx, 0      ;HIGH WORD.
	mov dx, [clockspeed]
	shr dx,1
	mov ah, 86h    ;WAIT.
	int 15h
	pop dx
	pop cx
	pop ax
	pop bx
	ret

waitmore:
; in bx == 12h is 1 sec
; destroys ax,bx,cx,dx
	push ax
	push bx
	push cx
	push dx
	mov ax,0h
	int 1ah
	add dx, bx
	mov bx,dx
waitloop:
	mov ax,0h
	int 1ah
	cmp bx,dx
	jnz waitloop
	pop dx
	pop cx
	pop bx
	pop ax
	ret

exit:
	mov dx,0388h
	mov al,0b0h
	out dx,al
	inc dx
	xor al,al
	out dx,al
	mov ax,04c00h
	int 21h

clockspeed: dw 0

highlow:	db 0

tune:
	file 'RAWSONG.RAW'

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