Re: 5.25" PROM Code Question

["Charlie" <charlied@NOSPAMbboard.com>]

"Bryan Parkoff" <BParkoff@satx.rr.com> wrote in message
gFmdnbjF9qxzXc-jXTWQkQ@giganews.com">news:gFmdnbjF9qxzXc-jXTWQkQ@giganews.com...
>     It does not make sense because there is no table in page 3.
>
> --
> Yours Truly,
>
> Bryan Parkoff

Bryan,

There is a table in page 3 after the routine at $C600 creates it.  Remember
that when you first boot a disk there is no translate table any where in the
computer, only on the disk.  So how do you initially translate (decode) the
first sector you read?  The looping you mentioned cleverly creates the table.
This saves having to put the table in ROM.
The table in page 3 is just used for the initial boot process I believe.

Charlie


> BParkoff@satx.rr.com
> "Doug Kwan" <NOSPAMdkwan@transmeta.com> wrote in message
> 1045608479.226326@palladium.transmeta.com">news:1045608479.226326@palladium.transmeta.com...
> > The loop synthesizes the 6-2 GCR decoding table in page 3.
> >
> > Bryan Parkoff <BParkoff@satx.rr.com> wrote:
> > :     I dump 5.25" Drive's PROM code into filename.  Please take a look
> below.
> > : Please tell me what is this?  I have noticed that it uses too much loops
> > : over and over before it begins to read track 0 and sector 0.  Why is
> loop
> > : necessary?  What is the loop use for?
> >
> >
>
>