13 Oct
2008
13 Oct
'08
12:21 p.m.
Ethan Dicks wrote:
P.S. - I found another type of composite circuit using
a CD4011 as an
inverter and a CD4066 to mix the signals,
Sounds like the circuit I have here from "The PET Revealed".
but for some reason I don't
have all the components labelled on my drawing - the cap on hsync in
particular.
It's not labeled on the diagram in the book, nor does the text say what
value it is.
One interesting variation with that one is that the
'LS02
circuit has a 1.5K pulldown on hsync between the cap and the gate,
while the CD4011/CD4066 circuit has a 10K pot. How much adjustment on
hsync is likely to be needed between the PET and the first gate of the
composite circuit?
The text in the book says "You may encounter problems with the
horizontal hold, but these can usually be cured by adjusting R1", and
goes on to speak of low quality monitors or converted TVs...
Cheers.
Phill.
--
Phill Harvey-Smith, Programmer, Hardware hacker, and general eccentric !
"You can twist perceptions, but reality won't budge" -- Rush.