Adding 16550 to Atari 8-bit

TXG/MNX · December 27, 2002

Hi,

Anyone ever connected a 16550 chip to the 8-bit Atari. I have read that some people in the c64 scene have used this chip and claim to have speeds up-to 115.200 on a normal c64 computer. This would be great. The max. speed now on the 8-bit atari is 19.200....

TXG/MNX

Curt Vendel · December 27, 2002

Well the SIO bus is limited to a burst speed of 38.4K so you wont be getting to the speeds you want there. You could fashion an adhoc device onto the cartridge port or go the PBI/ECI route which makes the most sense. The PBI/ECI is supposed to have a top speed of 100K or so, so thats going to be the best beat for you.

Earl Rice did a multi-part article on building a Serial Port device for the PBI bus in Antic magazine back (83??? Someone correct me if I'm wrong) however, I spoke with Earl recently and he explained that the article was written based on very early PBI specification data and is actually incorrect in several area's.

There is a recent article on a PBI/ECI tutorial in one of the latest issues of myatari.net Magazine that goes into developing PBI devices, so that would be an excellent place to start to get a could crash course on developing a PBI device. You could go the easy route and just hardcode the serial device to 56K or higher to simplify things, then maybe work on making it either jumper select or get fancy and do it in software. If you're going to develop such a device, consider tossing a Parallel port onto it and giving it 16-64K of buffer space too. It would look super-slick if you mounted it all into an Atari 1064 Memory Module case (hint hint ;-)