From: Pete Rittwage (peter_at_rittwage.com)
Date: 2008-01-05 19:38:50
Ruud@baltissen.org wrote:
> Hallo allemaal
>
>
> As I already mentioned I have a problem with formatting the disk: the first
> time ends fine, the second format ends with a write error. No explanation
> at all :(
> Yesterday I stumbled into something that makes the problem even weirder. I
> did a move towards the 16 MB disk and decided to format all 256 sectors of
> a track. See below, Y=sector, X=track:
>
> ldy #0
>
> ;@@00
> ; Fill sector with zeros
> FormatTrack01 tya
>
> jsr SetTSparms3
>
> lda #$30 ; write sector
> jsr SendCommand
>
> lda #0
> tax
>
> FormatTrack02 sta IDEdata
> inx
> bne FormatTrack02
>
> dey ; next sector?
> ; bne FormatTrack01 ; yes, ->
>
> ; ldy #0
> ; dey
> bpl FormatTrack01
>
> jmp L_FD8B
>
>
> Rest of source:
> http://www.baltissen.org/files/idejd4.asm
>
> If you ommit the lines starting with ';', you get my first try. Which is
> wrong as only track 0 will be formatted. BPL is an inheritance of
> formatting from track 21 (or less) downwards (see:
> http://www.baltissen.org/files/idejd4.asm and look for !&&12). But in this
> case, after only formatting sector zero, I can format the disk as many
> times without any error. So I thought, had it to do with the BPL command?
>
> Finding no reasonable explanation at L_FD8B and further, I just tried to
> copy the circumstances by first inserting the BNE (as it should be) and
> then adding this LDY #0 (in fact not needed) and DEY. Still got my error :(
>
> So I restored things and tried formatting the track starting with sector 1
> instead of 0 (LDY #1 instead of LDY #0 just above ;@@00), same result. Only
> then when I only format sector zero, I have no error.
>
> Why ????
>
>
> --
> ___
> / __|__
> / / |_/ Groetjes, from a very puzzled Ruud
> \ \__|_\
> \___| http://Ruud.C64.org
>
>
>
>
>
>
>
> Message was sent through the cbm-hackers mailing list
X is just being used as a scratch register here, it is always reset to
zero each time around. Y is the track, not the sector like in the
comments? It looks like this code should format sector zero only on
tracks 0-255 if I am reading the SetTSparms3 code correctly?
--
-
Pete Rittwage
http://rittwage.com
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