19 Mar
2018
19 Mar
'18
1:34 p.m.
On Mar 19, 2018, at 3:05 PM, Warner Losh via cctalk
<cctalk at classiccmp.org> wrote:
...
For the Rainbow (and I think the Pro to), there's a DC coupling that's not
normal that needs to be removed with a series capacitor:
From 3.5.3 Keyboard/Monitor Connector (J3) Signals of The Rainbow 100
Technical Manual (EK-PC100-TM):
Video signals - Similar to EIA RS-170
*NOTE*
*The composite video (Mono Video) signal on pin 12 is dc coupled and
therefore not in strict agreement with RS-170. To agree with RS-170, the
composite video signal would require a 10 microfarad capacitor in series
with the output. *
I have all the parts needed to drive a modern LCD monitor using the Video
Camera to VGA adapter things, but haven't yet had the time to try it out.
Yes, the Pro manual also mentions that it's DC coupled.
That probably makes sense, given that computer graphics are likely to have long stretches
of constant output, unlike TV type video. Unless the DC coupling causes problems it would
make sense to leave it alone.
paul