21 Dec
2013
21 Dec
'13
2:56 p.m.
On 12/21/2013 01:03 PM, Steven Hirsch wrote:
Does anyone have a source for a Fujitsu MB8866 FDC
chip? I've found
some mention of it being a direct substitution for a WD1791, but the
latter does not cooperate in this machine.
Careful--the 8866 is a sub for the bare-no-suffix old WD1791; the MB8876
substitutes for the more common 1791-01 1791-02. The big difference is
in the operation of pin 33 (which shouldn't matter) and the compare
feature bits in the read and write commands, which may be what's
tripping you up.
So if you can't find an 8866, try for a no-suffix 1791.
--Chuck