Re: Dual port serial card?

[shack@deimos.frii.com (Randy Shackelford)]

In article <50pljr$rpg@flood.weeg.uiowa.edu>,
Steven Nelson <snelson@news.uiowa.edu> wrote:
>From article <50o1i6$9s5@galileo.cuug.ab.ca>, by scott@galileo.cuug.ab.ca (Scott Barker):
>> Has anyone ever heard of a dual-port serial card? I've got an apple // card
>> which claims to be one. I've got no docs, though. Any ideas how it might work?
>> 
>
>What card?  The Apple IIe Workstation networking card has two serial ports.
>But I don't think that is what you are asking about.
>
>I've never seen one, but one could be done.  Most 6850 and 6551 based
>serial cards used only 4 addresses in the Cn8x space (6850 used 2, 6551
>used 4).  Since 16 addresses are available in that space, a quad-port
>serial card would not have to be too exotic.  Each port would be controlled
>by a different set of addresses.  If phantom slots were implemented, even
>more could be controlled.  

Of course there are multiport serial cards. The best known is the BusinessCard
from Street Electronics. It has a printer port, modem port, and Thunderclock
compatible clock. It used a technique called phantom slotting to make it appear
as two serial cards and a clock card. Those who were into Apple IIs when the
IIgs came out will remember that reviewers said phantom slot cards cause the
IIgs to puke and not to try 'em. The BusinessCard had a cool feature in an
enhanced //e, it had a mousetext and mouse pulldown menu setup in the firmware
to configure the card. The only person I ever knew with one of these cards
had an unenhanced //e so I never got to see it in action.
-- 
Randy Shackelford                                 US Air Force officer
shack@frii.com                                    and Apple aficionado