19 Mar
2010
19 Mar
'10
9:07 p.m.
Thanks , HP was talking about adding a graphics chip
(ROM).
My printer -- the one the schematics were produced from -- is a 2671G.
The 2671 has an empty socket on the HP-IB interface
board, the one closest
to the printer PCB is empty.
I think mine does too. I am pretty sure I indicated that the external ROM
for that microcontroller was 'N/F' (meaning 'Not Fitted'). You could use
a 8039 microcnotrller and an extenal ROM or an 8049. One of the switches
on the itnerface board sets the state of the EA pin
I'm not sure if that's the one, it could be
the ROM on the printer PCB it
self.
I am also almost certain that my printer PCB has an external ROM. I think
it's an 8049 microcnnotroller on there too. Again, I would have to check
the settings of the swithes to see if the interal ROM of that
microcontroller is used). Of course an 8049 with EA pulled hich acts just
like an 8039 AFAIK.
It would be very nice if you find out what needs to be
replaced, on the
printer PCB on the one I have a 8039 with external ROM is used.
I should have some time tomorrow to pull the covers and check. We can
compare our 2 machines to see jsut what the differences are.
-tony