Dave, I just noticed something interesting about this.hoglet wrote: One more thing... Mode 7 when using sRGB mode to a SCART TV looks perfect, and is indistinguishable from a real Beeb:
Mode 7, resampled to VGA by the scan doubler, looks not so great!
Some of the uprights, e.g. the on the M, end up different widths. This is caused by resampling the 12MHz teletext pixels with a 32MHz VGA clock.
When I first power on and program the board, I see what you describe, i.e. variable width uprights.
If I then, do a hard reset using SW the MODE 7 display gets a lot better, i.e. uprights are the same widths.