From a uCs perspective that needs to output 4-bit data, it comes
> pre-parsed and saves some shifting and ANDing steps to make it
> presentable.
It has to be balanced, of course, with limited EPROM space. If you
_really_ wanted to minimize bit fiddling time, you'd put each four-bit
unit in its own byte. Clearly they didn't want to double the space
used, though.
I'd love to know more about that divider chip. It seems like a fairly
custom sort of thing. Guess I should spend some quality time with the
databooks on Bitsavers to see if I can find anything related.
> I remember seeing an article on how to replace the narrow DIP with a
> DIY std wide DIP socket for "modern" EEPROMs.
There are adapters that make a 27xx (or 28xx) ROM usable in a one-shot
PROM socket. Among other places, Sandy Ganz maybe? had one for original
Syntor. The original used two PROMs, one for frequency data, and one
for PL.
> Did you ever write anything to generate the codeplug data the
> original Syntor?
I did not. Just the X.
Pretty sure I have the suitcase programmer ROMs for the original Syntor
frequency and PL programming, if anyone is feeling a 6805 disassembly
project. Those radios are nowhere near as useful though, in my opinion,
because their front ends are far narrower than the X and X9000.
De
