RE: Converting Apple II video bitstream into HDMI (with an RP2040?)

agancel — Thu, 27 Oct 2022 17:28:59 GMT

Hi James,

Love your work, you have so many interresting project.

i wonder if you sell this little videocard, because the board shown is professional rank

Regards.

RE: Converting Apple II video bitstream into HDMI (with an RP2040?)

lukazi — Tue, 22 Feb 2022 10:58:59 GMT

Hi James, Love your work (especially the single-chip Apple II stuff). Interesting idea options you have. I've done a few Apple II video converters. In case it helps this has been my experience.

USB: I did this many years ago. I used a Cypress EX-USB FX2LP to pass Apple II video via USB to a PC. Worked well but as you said, it requires a PC to output the display.

RPi Pico / DVI Sock: I did this but would not recommend it. Monochrome worked well but I could not get colour output from the dvi driver working on several TVs/monitors. RPi Pico to VGA sounds like a better way to use the Pico.

HDMI-1: I used Apple II to RPi Pico as serial to parallel converter / buffer then 8bit data bus to RPi Zero. Zero processes the data on the fly and outputs directly to the HDMI Frame Buffer. Colour was easily added with just a few lines of code. No complex math needed just two lookup tables (palette and 12bit colour relationship). I'm in the process of documenting this up for my blog - lukazi at blogspot dot com.

HDMI-2: Tang Nano 4K FPGA. Looks promising. I have one on order.

Looking forward to seeing your solution. Cheers, Alex.