"intelligent" disk drives

[Ethan Dicks]

On Sun, Nov 18, 2007 at 10:22:36PM -0000, Ensor wrote:
> Hi,
> 
>  >....I think he was joking, of course, given the
>  >horrendous bottlenecks in its software and its bus
>  >protocol.
> 
> To be fair, the only thing wrong with the CBM serial bus was the speed it 
> ran at....or rather the lack of it....

Indeed.  There's a well-documented saga of how the bit-serialization was
supposed to be done in hardware, but could not due to bugs with the interface
chip.  IIRC, it was a CB2 problem with the 6522 VIAs on the 1540 drive and
the on the VIC-20 (the first machine to use the CBM serial bus).  IIRC, the
problem was fixed with the 6526 CIAs, but the moment had passed.

The link was so slow that for a commercial product, "Micro Mother Goose",
we employed a simple compression scheme on the splash screen and menu
screens because it meant that we were loading fewer overall bytes from the
drive, so it loaded faster.  We also saved space on the diskette, but that
was an entirely unnecessary optimization.

-ethan

-- 
Ethan Dicks, A-333-S     Current South Pole Weather at 18-Nov-2007 at 22:30 Z
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Ethan.Dicks at usap.gov            http://penguincentral.com/penguincentral.html