Re: Virtual serial drive

[Michael J. Mahon <mjmahon@aol.com>]

<bpiltz@gmail.com> wrote:
> Well, if SSC serial cards are available new or used for only $20, it
> would be foolish not to invest in one for this virtual serial drive, and
> also for faster serial transfers of .dsk images.
> 
> Had a thought, could the code for the virtual serial disk driver be
> reloacted to an unused area (if there is any with ProDOS there) as an
> alternative to putting it into ROM?
> 
> Agreed that ROM is the best place for the code, but how will this be
> easilly accomplished? Can the SSC's ROM be flash and is it an EPROM?
> 
> re: the date, I agree it is an interesting idea, but it would create
> overhead and reduce speed of transfers, even it it is only 2 or 4 bytes
> in addition to the 512 bytes / block transfered. Perhaps ADTPro could
> have the *option* to do this rather than the hard-coded *feature*. For
> those who want to maximize bandwidth, there may be other tricks as well,
> such as an easy RLE compression of each packet, etc.

Yes, it's an EPROM--easy. 

4 bytes is less than 1% overhead only on reads, and in return you get
trivial client code (move 4 bytes)--that seems like an obvious design
choice. ;-)

-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon