A86: Re: User interrupt

To: <assembly-86@lists.ticalc.org>
Subject: A86: Re: User interrupt
From: "Dux Gregis" <assets@eden.rutgers.edu>
Date: Fri, 1 Jan 1999 17:43:07 -0700
Delivered-To: assembly-86-outgoing@towerguard.unix.edu.sollentuna.se
Reply-To: assembly-86@lists.ticalc.org



There's a flag you can check to see if an asm program is running:

 bit ProgramExecuting,(iy+NewDispf)

or

 bit 6,(iy+$17)


>
>I was experimenting with Matt Johnson's Interrupt
>examples and i thought that it was nifty to have
>a sprite display your initials or something in the
>upper-right corner of the screen. What i didn't want
>though was to have it appear while playing an asm
>game. This is what i came up with:
>
>(this is not the whole prog)
>
>            ld        hl,0
>            add    hl,sp
>            ld        b,10
>stack_search:
>            ld        (instr+2),hl            ; self changing code (ld
de,(hl)
>instr:    ld        de,($0000)
>            call     cp_n_de
>            ret      c
>            inc      hl
>            inc      hl
>            djnz    stack_search
>;--------------------------------------------------------------
>cp_n_de:
>            ld       a,$D7
>            cp      d
>            ret     nz
>            ld       a,$48
>            cp      e
>            ret
>
>It's probably not perfect but it works, it searches through
>the stack to find out if any asm program was running
>when the interrupt occured.
>
>Has this been done before ?
>
>Any comments ?
>
>/Thomas Bladh
>