Re: SSC mods

[sjensen@cello.gina.calstate.edu (Steve Jensen)]

Here is some info on the Turbo ASB:

Lightning Systems Product Information Sheet
 
Lightning Systems offers two (2) products for the Apple // line of computers.
 
6551-ACIA
---------
This is a replacement chip for the 6551 ACIA (Asynchronous Communications
Interface Adapter) that is standard on most Serial Interface cards for the
Apple //.
 
Why do you need a replacement chip? Simple, the 6551 chip that is on most
Serial Interface cards has a design flaw in it that causes it to lose a
character every time the CTS line is switched.
 
In most cases, this is not a problem. However, with modem speeds 
continuing to
rise, people have started using Hardware Handshaking cables to connect 
their
computers to their modems to achieve even higher speeds. This is where the
problem lies.
 
In typical Hardware Handshaking installations, the computer is sending and
receiving faster than the modem can receive and transmit data. This means
that the computer and the modem need to communicate between themselves
to tell each other when it's ok to send or receive data. When the buffer
fills up, the modem switches the CTS (Clear To Send) line to notify the
computer that it is no longer ok to send data. At this point the 6551 chip
stops sending data immediately! This is bad. The 6551 may have been right 
in
the middle of sending a character (normally 10 bits). That character is 
now
lost causing an error in the transmission.
 
This is where the 6551-ACIA comes in. This new 6551 chip fixes the 
problem.
This is a direct replacement for the 6551 chip you now have.
 
Turbo ASB
---------
Do you have a high-speed modem, or other high-speed serial communications
device?
Did you know that most Serial Cards for the Apple // are limited to
only 19.2k bps?
 
Well, they don't have to be anymore. The Turbo ASB can blow away that 
nasty
19.2k bps barrier. With the Turbo ASB, your serial communications can run 
as
fast as 230,400 bps!!!
 
The Turbo ASB is an add-on card replaces that pokey old 6551 chip on your
Serial Interface Card and transforms it into a speed demon.
 
The Turbo ASB supports all the standard bps rates you are used to, (slow.)
and adds 38.4k, 57.6k, 115.2k and 230.4k!
 
At this time the Turbo ASB is supported by ProTERM, Spectrum and ANSITerm.
The Turbo ASB includes a 6551-ACIA chip.
 
Pricing
-------
The 6551-ACIA is $4.00 each. The Turbo ASB is $27.00 each.
 
Shipping and handling is as follows:
 
Within the U.S., $3.00 per order.
Canada and Mexico, $5.00 per order.
Everywhere else, $10.00 per order.
 
Include an E-Mail address if you have one.
 
Lightning Systems
P.O. Box 4
Mukwonago, WI  53149-0004
(414) 363-4282 BBS


(Sorry about the long lines)

-- 
sjensen@cello.gina.calstate.edu          8-()
                                        - _ !    Still smokin'.