I've recently decided to revisit my childhood and acquired an Apple IIe platinum. The motherboard says 1987 and International NTSC.
(I'm mucking around with 6502 assembler on my PC and debugging/emulating with Applewin currently)
I have no dedicated composite or Apple monitor, so I bought a no name composite to HDMI adapter. (I couldnt get hold of a vidHD :( )
And here it what I have found :-
- -I get a good stable picture (in monochrome ) in 40 column text mode, with no sync issues
- -In High Res (6 color) mode, the screen loses sync every one or two seconds and there is no color (could be the adapter maybe)
- -In 80 column mode I get only even column characters if I type PR#3 to enter 80 column mode (I have 128k via an Ian Kim Apple2 Overdrive card)
- -Double Hires is missing columns of pixels, and is monochrome and and also wont sync (seems linked to 80 double characters)
So even if the HDMI adapter isnt right, I think I have a problem with the display HW / circuitry. I dont quite know enough to be dangerous yet.
Maybe someone on these forums can offer some advice before I start searching for scxhematics and oscilloscopes
Kind Regards, Nick