Re: Europlus PAL card questions

[Stephen Shaw <xstephenx@apple2.org.za>]

On Tue, 05 Feb 2002 12:43:16 +0100, Linards Ticmanis wrote:

> I received a PAL card through eBay today. It's a clone I assume, the PCB
> is marked "PAL[encoder]", it has the little modulator box with the
> output marked "UHF" and another output marked "Video O P". Otherwise
> there is only a handwritten "OK 27.9.83". The PCB is blue in color.
> There are four ICs, a TCA650, a 74LS175, a 74LS164 and a 74LS74.

The TCA 650 is a PAL encoder chip. You will find this chip on the PAL IIe
motherboard as well.

>
> The thing is thus from late 1983 and is originally from the UK as far as
> I know. Can somebody identify what exactly I've got there? Am I right
> that it's supposed to go into slot 7 of an Europlus?

Came from a firm called Digitek. Yes it must go into slot 7.

>
> The problem is, it doesn't seem to work. I've only tried an amber
> monitor so far (kind of defeats the purpose...) The picture I get has
> extremely low contrast - so low that you can just sort of guess that
> there's something on the screen amid the snow that appears when I turn
> the monitor to full brightness. Text mode is even worse snow-wise than
> Hires or Lores Graphics. In Graphics mode lines drawn with HPLOT can be
> seen if you look closely, in text mode the snow is so strong that even
> the blinking cursor can just be noticed, while NORMAL text isn't visible
> at all. I've only tried the Video Out, maybe the TV Out will work
> better, I'll have to try though I doubt it.

You must make up an adapter from RCA plug to UHF TV aerial/antenna plug.
VHF output is on VHF channels 1-3 and UHF above channel 36.
  
>
> The guy who sold it said it had been stored away for many years, but had
> worked before that. Are there any electronic components except EPROMS
> (which the card doesn't have) that get bad with age when not in use?
> There are a few small electrolytical caps (100�F 16V), would it make
> sense to replace those? What about quartzes? There is one, unfortunately
> the markings aren't readable any more.

No it should be OK. Caps in switched mode power supplies are the worst as
they take a hammering (literally!)

>
> Also, does anybody have documentation, schematics or troubleshooting
> hints for those beasts??
>
> Thanks a lot in advance,

-- 
... Transformer designers take turns doing it.