ASM MUSIC CALL.

[Packobilly]

Hi all!
I have this asm call routine for a .pt3 music with its player to play in a BASIC loader:

START   SET 60000
            LD (START+10), A
            CALL START
            EI

LOOP    HALT
            CALL START+5
            LD A, (START+10)
            RLA
            JR NC, LOOP

RET
                                             
When I run it, the music starts playing, but none of the IF INKEY$ options works.
It seems that until the music ends you cannot press any key.
I compiled the song with VT Player.
Is there a way to solve this, so that at the same time as the music is running the menu in BASIC works?
Thank you so much!!

[alessandro]

Hi Packobilly,

in that code you posted there are no instructions reading the keyboard. Moreover, INKEY$ is a BASIC instruction, and the Spectrum won't return to BASIC until the last LOOP cycle has been performed and the RET instruction has been executed. That means you cannot play the music, or better said, run any machine code program, and run a BASIC instruction at the same time.

This code plays the music until a key is pressed. Assemble it and try it by entering PAUSE 1: RANDOMIZE USR YYYYY (where YYYYY is the address where you assembled it).

 PLAYER EQU XXXXX ; XXXXX = address of the music player program

 ORG YYYYY ; YYYYY = address where this code will be assembled, length 31 bytes

 LD A,1
 LD (PLAYER+10),A
 CALL PLAYER
 EI
LOOP:
 HALT
 CALL PLAYER+5
 XOR A
 IN A,(254)
 CPL
 AND 31
 JR NZ,FINE
 LD A,(PLAYER+10)
 RLA
 JR NC,LOOP
FINE:
 CALL PLAYER+8
 RET

[Packobilly]

Thanks, Alessandro.
As you can see, I am trying a little more complicated things and thanks to advice like yours I am learning little by little.
I will try this routine that surely works perfectly.
Cheers!