Re: iic boot from serial port?

[Paul Guertin <pg@sff.net>]

CUTjefbla@bconnex.net (Jeff Blakeney) wrote:

> On Sat, 17 Feb 2001 18:40:24 +0900, Paul Guertin <pg@sff.net> wrote:
> >[bidirectional communication with a parallel card] 
> >there are 5 lines available on the Grappler, which means you can
> >receive only 4 bits at a time.
>
> Then, while this may be fun for someone to do, I don't see this as
> giving much of a speed improvement over using a serial connection.  At
> least not for reading, which is the most important as it is done most
> often.

Do you have any data on how fast a parallel port can go? I used
to have a parallel-port Zip drive on my PC and it was certainly
much faster than a 19200 bps serial connection.

> Writing would be faster by a fair amount so it might be worthwhile for
> someone who needs to write lots of data from their Apple II to another
> computer.

E.g. someone wanting to archive disks, which is one of the reasons
I investigated the parallel port. But in the end it proved faster
to send all my disks over a serial line than to write and debug a
parallel port protocol. Especially since I managed to fry a PC's
parallel port while experimenting.

> It also kind of eliminates the possibility using this system to hook
> up two Apple IIs together unless you code the driver to support only
> sending 4 bits at a time instead of 8.

Crazy idea that might even work: one could put two parallel cards
in an Apple, sending 4 bits from each card...

> Personally, I'd stick to a serial driver as null modem cables are
> easily found or made and it is a standard way of connecting computers.

Yup. There was a hardware hack that allowed a Super Serial card
to support up to 230kbps (Turbo ASB or something like that). That's
certainly the sanest way to do it.

Paul