Re: Apple //c smartport compact flash adapter

[Eric Rucker <bhtooefr@gmail.com>]

On Feb 3, 7:02 pm, mdj <mdj....@gmail.com> wrote:
> Interesting - sounds like there's a handshake between bytes that
> limits its throughput.
>
> The Rev C. SCSI (from memory, I think we did this once before) is
> around 35kb/s on my accelerated IIe. I'd say they're both slow
> compared to other options, and certainly slow compared to what's
> achievable in a bus connected card.
>
> My marketing skills aren't the best, but I'd guess the majority of
> people wanting such a thing on a IIc would be more than satisfied with
> SmartPort speeds. The 'power users' are already using IIe's or IIgs's
> anyway.
>
> Matt

Theoretical maximum transfer rate on a UniDisk 3.5 is 500 kb/s. (From
http://docs.info.apple.com/article.html?artnum=1307&coll=ap)

So, that's 62.5 kB/s.

However, that theoretical maximum can only be approached on a IIGS, I
believe. (Even the accelerated 8-bits will likely stay at 1 MHz the
whole time.) There's lots of SmartPort overhead to deal with, and the
8-bit machines will have to deal with that overhead, whereas a IIGS
can speed up to 2.8 MHz and go past all of that overhead, between
transfers.