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Re: Disks that boot on 13 and 16 sector ROMs?

Bryan Parkoff wrote:
> > Maybe I'm missing something simple, but how can a 13-sector controller
> > read the 16-sector disk contents?
>     No, you can't.  This 13-sector controller card cannot read 16 sector
> because it has different logic sequencer ROM which it only reads 9 bits of
> SYNC nibble.  It is designed to detect 9 bit SYNC nibble before it starts to
> read data.  If logic sequencer ROM is swaped to new logic sequencer ROM
> which it supports 10 bit SYNC nibble, it can read both 13 sector and 16
> sector data.  You can still switch 13/16 sector PROM while it keeps 16
> sector logic sequencer ROM.
>     Hopefully, it helps.
>
> Bryan Parkoff

Bryan--

  Your description of the difference is not accurate. Neither sequencer
"detects" the SYNC bits directly. Rather, the sync bits combined with
the sequencer behavior are sufficient to ensure sequencing.

  The 13-sector sequencer cannot reliably capture certain bytes used in
the 16-sector data encoding.