DP8350 (and DP8367)
ard at p850ug1.demon.co.uk
Thu Mar 12 14:24:34 CDT 2009
> see the thread from 2003
> looks like this was a custom for HP
Well, I am not convinced it is totally custom, in that it has the DP8367
number as well as the HP1820-xxxx number (nost totally custom chips only
have the latter). I can well beleive it's a custom version of a standard
CRT controlelr, perhaps for a different screen format or something.
Anyway, I did a little more poking isnide my HP120 today. I believe the
DP8367 is closely related to the DP8350. Some of the pinouts machine up
(and not just bovious ones ). The internal registers seem to be loaded
in the same way _from the address lines_. It is connected to am 80 yte
shift register chip (I forget the number, MM5035??).
 For example, according to the HP125 boardswapper manual on
hpmuseum.net, one of the output ports on the terminal processor (a Z80A)
controls the 6 self-test LEDs and a line to the video controller to
select 50Hz or 60Hz vertical frequency. I can find this output port (an 8
it latch) on the the the terminal PCB, the bit that would set vertical
freuqencty is linked to a pin on the video controller chip, indeed on the
DP8350, that pibn does select vertical frequency)
Now, I can find _references_ to the DP8350 data sheet, but not the
complete data sheet. Does anyone have that one?
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