🚀 go-pugleaf

I am currently on an extended contract in Europe (coming from
Australia), and have recently being feeling lost without my hulking
great 386.  As I wanted portability (but have also already a
pocket computer) and a big extended keyboard, I wnet for an
Amstrad PPC512.

But the display is terrible.  So I thought, buy some plugs and
do an RGB connection to the TV.

Problem 1.  The Euro-connector "documentation" has a "blanking"
	   input (no further explanation),
	    The PC "documents" outputs including HSYNC and VSYNC 
	   (again no further explanation).

Problem 2.  Whilst the line frequency is only about 1% different,
	   the 625 vs 525 lines may be a problem (in Australia I
	   used a multinorm Sony Profile, here an ordinary Loewe)

Problem 3.  The Loewe has no sync polarity switch.

So I tried straight composite/monochrom video, calculated the new
values for the CRTC registers to adjust the frame frequency, and...
There was too much tearing for it to stabilize.

So I tried the RGB, "blanking" with both HSYNC and VSYNC and combined -
it didn't produce more than some faint fuzziness of different kinds.

So I tried the RGB, "blanking" with the monochrome signal.  That
was enough to stablize vertically for carefully selected values
(slightly different from best for composite video, both beyond the
calculated values).

Here I noticed it was most table with the text in the sync
position, suggesting that the sense of "blanking" was inverted.

So I tried the RGB with sync from the tuned TV station.  The
optimal response here corresponded with the calculated values,
with a slope on verticals (corresponding to the difference in
horizontal frequencies?) which varied slightly according to station
(as might be expected).

So I am now left feeling positive that the problem is that I can't
obtain the "blanking" signal required by the Euro-Connector.  Can
anyone support this supposition?  Can anyone provide more technical
details?  Suggest and invertion/combination circuit to synthesize
the required "blanking"?  Suggest where I might find an inverted
signal input somewhere in the Loewe M21 + Videotext?  (That is
preferable to some additional inversion box - there is actually a
cut out on the case for an sync polarity switch, but I don't know
what option brings that, and don't what BTX just for that reason!)

Any help or comments appreciated, especially on the two signal and
socket standards.

Cheers,

David Powers