Re: Commodore to S-Video or HDMI video?

From: Anders Carlsson <anders.carlsson_at_sfks.se>
Date: Thu, 19 Jul 2018 11:21:55 +0200
Message-ID: <b8973b36-ee90-ba51-4e48-d02c707a4d45@sfks.se>
Ruud Baltissen wrote:

> I remember having troubles with the older VIC-20 boards regarding the 
> video, even on my CM8233. At the end I had to use another output on 
> the 5-pins connector then the one normally used for the newer VIC-20s 
> and the C64. This was one of the reasons I hardly use the older 
> boards. The second reason is that I can use the same power supply for 
> the newer boards as for my C64.

Yes, the VIC-20 has composite video output on two pins, the regular pin 
4 (marked as Video Low in some manuals) and an extra signal on pin 5 
(marked as Video High). I think the Video High is a stronger signal 
(voltage?) meant for the RF modulator though it also has its own 5/6V 
power source in the same cable.

On newer VIC-20CR models, there no longer would be any difference 
between Video Low and Video High, which would explain if your newer VIC 
worked better on your monitors and TVs.

Wiring a cable with pins 2, 3, 5 instead of 2, 3, 4 would make it 
specific to early VIC-20, for displays where the Low signal may be too 
weak. I'll admit my two-prong VIC-20 with an early (?) 6561E video chip 
is firmly boxed away and for daily use I'm strictly using DIN-style CR 
models - both PAL and NTSC, but I might bring out my old two-prong and 
test with a regular composite video cable on various displays to 
determine if those yield a display or not.

On a partly related note, I've got a PAL model CGL M5 (UK branded 
version of the Japanese computer Sord M5). That one displays a colour 
picture on most CRTs and some LCDs, except some otherwise excellent 
Samsung LCD TVs capable of handling both PAL and NTSC, but which are 
unable to produce colours from the M5 composite video signal. Then again 
I used to have a genuine Sord M5 in PAL version, which displayed in B&W 
on my 1084 but in colour on other displays so it could very well be a 
case of signal strength and whether the TV/monitor accepts very weak 
signals. At first I thought the Sord branded machine was Japanese NTSC 
but since it displayed in colour on TVs otherwise known to NOT handle 
NTSC composite video, that could not be the case.

Best regards

Anders Carlsson
Received on 2018-07-19 12:01:39

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