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adding 82c55's to ting's board


I seem to be making progress in programming some video functions I need
and am hopeful I'll figure out how to do others, but I'm baffled by my
other major requirement, parallel I/O. I think if I had colon words to
address the 82c51, I could adapt them to addressing 82c55s which I can
install on prototyping area along with decoding logic to select 55 or 51
as necessary.
Failing that, I need to understand:
1. The relationship between the configuration register and I/O. Presumably
bit 21d or 14hex has to be set to address sram or I/O. I don't find any
explanation of this or any examples I can understand in Ting's
documentation. 
2. How to do this in colon. not just in machine code, though this would
work if I could figure out how.
3. In okchar28.seq, supplied with the board the tx/rx functions are shown
in assembler, but the addresses are 7fffc-d-e-f which com to 80000-1-2-3,
which don't appear to be I/O addresses.
I'd appreciate any help I can get on this.