Difference between SIO and 2SIO boards

[mail@gabrielegan.com]

I've got the manual for the 2SIO board but I can't see one on the Support Site for the SIO board. I'm trying to get an understanding of how these two boards differed. It seems that several settings that were hard-wired (or jumpered) on the SIO board are software selectable on the 2SIO, and from the sample programs that Mike supplies it looks like one has to initialize 2SIO ports before use, whereas SIO don't need this. I'd be interested if anyone knows of a simple explanation somewhere of how these boards differed, and what it means for an Altair clone to have both kinds of board operating at once: is that what people did, install multiple serial boards?

[AltairClone]

Download the 88-ACR board manual. It covers the 88-SIO board and schematics. I'll post a stand-alone 88-SIO manual as well.

Mike