"Simon Williams" <see_sig_for_valid_email@no.spam> wrote in message
news:1gd68wp.1p6md43j3rbeeN%see_sig_for_valid_email@no.spam...
> Here's an idea I've been toying with, I wouldn't mind some feedback on
> its feasibility.
> I'm working on a new version of the Timelord drum sequencer and thought
> it would be rather nice to have more than ~20K available for audio
> samples. Since the new interface is 80-columns, it pretty much means
> that it'll only run on 128K machines anyway, so it would be smart to use
> the extra 64K for the audio samples. The problem is that DAC522 only
> works in the main 64K, so I would need a way to move samples from aux
> memory to main memory (hopefully my terminology is correct here), and so
> far I haven't found any documented technique for accomplishing this. If
> anyone can point me in the right direction, I'd very much appreciate it.
> Also, if anyone has done something similar, I'm curious as to how much
> of a time penalty would be incurred.
> -simon

For simplicity, there will be a lot of that here, let's limit it to an
enhanced 128K machine.

We'll take advantage of the $C311 AUXMOVE routine and use 2K blocks for
clarity. When you get
to coding for 20k blocks the routine will be the same and the speed good
enough for only a blip.
Those accustomed to vinyl will feel nostalgic.


AUXMOVE         EQU $ C311  ;carry=1 main>aux carry=0 aux>main
STARTLO         EQU $ 3C
STARTHI         EQU $ 3D
ENDLO           EQU $ 3E
ENDHI           EQU $ 3F
DESTINATIONLO   EQU $ 42
DESTINATIONHI   EQU $ 43

    LDA #0 ;PAGE ALIGN AND DON'T MESS WITH THESE AGAIN
    STA STARTLO
    STA ENDLO
    STA DESTINATIONLO
;BLOAD SAMPLE1 ,A$2000,L8192
    LDA #$20
    STA STARTHI
    STA DESTINATIONHI
    LDA #$40
    STA ENDHI
    SEC          ;MAIN TO AUX
    JSR AUXMOVE
;BLOAD SAMPLE2 ,A$2000,L8192
    LDA #$20
    STA STARTHI
    LDA #$40
    STA DESTINATIONHI
    STA ENDHI
    SEC           ;MAIN TO AUX
    JSR AUXMOVE
;BLOAD SAMPLE3 ,A$2000,L8192
    LDA #$20
    STA STARTHI
    LDA #$40
    STA ENDHI
    LDA #$60
    STA DESTINATIONHI
    SEC           ;MAIN TO AUX
    JSR AUXMOVE
;AUXMEM HAS 3 SAMPLES FROM $2000 TO $7FFF

    LDA #$20
    STA STARTHI
    STA DESTINATIONHI
    LDA #$40
    STA ENDHI
    CLC           ;AUX TO MAIN
    JSR AUXMOVE
    JSR DAC522    ;PLAY THE SAMPLE
    LDA #$20
    STA DESTINATIONHI
    LDA #$40
    STA STARTHI
    LDA #$60
    STA ENDHI
    CLC           ;AUX TO MAIN
    JSR AUXMOVE
    JSR DAC522     ;PLAY THE SAMPLE
    LDA #$20
    STA DESTINATIONHI
    LDA #$60
    STA STARTHI
    LDA #$80
    STA ENDHI
    CLC           ;AUX TO MAIN
    JSR AUXMOVE
    JSR DAC522     ;PLAY THE SAMPLE

I hope that gives you an idea. Of course in practice you would use loops and
perhaps tables. I used straight line execution to show the steps clearer.

If AUXMOVE doesn't mess with your initial values you might


  LDA STARTHI
  CLC
  ADC #$20
  STA STARTHI
  LDA ENDHI
  CLC
  ADC #$20
  STA ENDHI

Laine...

PS if using 80 col. or graphics  make sure you don't load into those
sections of auxmem. Mainly graphics with the above routine.