Re: Super Serial Card Question?

[bieling@terra.es (Jorge Chamorro Bieling)]

Michael J. Mahon <mjmahon@aol.com> wrote:

> If you drop a $10 into the 6551 speed register, it runs at 115kbps.
> Apparently, this is not well known, since someone sells a "turbo"
> option daughterboard to achieve this speed, too.

Michael you're being bad...

There's a hardware-based "turbo option daughterboard" because it's not
possible to speed up the SSC to 230.4 kbps via software:

(it) "...allows up to 230,400 bps on the Super Serial Card and also for
a second card to be installed in the adjacent Slot...
...with a software option to allow the Super Serial Card to be pushed
past it's original limit of 19.2k..."

That's because highest baudrate the 6551 can be setup for, is, in this
case, 1,843,200/16 == 115,200, or XTAL/16.

To make it run @230.4 kbps, you have to either exchange the XTAL or feed
a clock through the 6551's Receive Clock (RxC) input, there's *no way*
to make it via software.
-- 
Jorge Chamorro Bieling