1 Aug
2015
1 Aug
'15
7:57 a.m.
SOME of the later S100 systems had regulated supplies and then ditched the board
regulators, usually leaving a place to put a regulator with just a jumper wire in place of
the regulator.
tony duell <ard at p850ug1.demon.co.uk> wrote:
I was going to say that that heatsink didn't look original, but fortunately I
kept my mouth shut and didn't insert my foot :-)
I've only seen the later black 380Z's with built-in 5.25" drives, first at
school
and now the one I own. On those the PSU is entirely internal, it's a little
chassis that fits round the mains transformer and carries a PCB of
recctifiers, regulators, etc. For some odd reason the schematic of that is not
in the manual, I guess I should draw it out sometime. It's not complicated.
Thinking about it, I do wonder what that heatsink/regulator is doing in an S100
system. Most likely it is the original RML supply and somebody has connected
to the unregulated inputs to its regulators
-tony
... Which also may well not be RML original. The 380Z has a regulated PSU,
S100 has separate regulators on each board and an unregulated PSU.
Indeed, although I do recall a heatsink mounted externally on the back of
the chassis (where the fan would be on the later hardware) with the early
machines - I just don't know details of the internal PSU.