Brian SwetlandUpdating the Apple II VGA PCB a bit:
- remove debug headers
- add project URL silkscreen
- more accessible USB connector
- improve silkscreen information
- remove solder mask from card edge
- reduce size of board slightly
Time to make a map of where everything is before hooking up the oscilloscope. I find this ends up being a huge timesaver. Actual silkscreen labels on everything is even nicer, but often there just isn't room for it all to fit.
This board has /IOSEL wired up and the VGA outputs used as debug pins -- using it to develop disk or IO interface glue and better understand the timing of everything.
Shuffled stuff around so the Apple IIe can live next to the workstation for development fun. Reading test data from a modified Apple II VGA card.
Next: using the Apple II VGA board as a development vehicle for other Apple II interfaces. All rigged up with SWD debug, serial out, and a big 'ol RESET button just in case.
For anyone wanting to build their own, all the Apple II VGA PCB files are now available on github:
https://github.com/swetland/appleii-vga
Apple II VGA, in kit form to send to a friend.
So, it turns out that the Apple II VGA thing Just Works (tm). All credit to Mark Aikens who came up with the design and wrote the Pico firmware. I just did the PCB layout and assembly.
See the original project here:
https://github.com/markadev/AppleII-VGA
I just realized I don't actually own any LCD displays with VGA in (though I do have a cheapo VGA->HDMI adapter around here somewhere). I do happen to own *one* remaining CRT, so I used that to try the test pattern mode. Looks like the VGA out side of the firmware is happy at least!
My soldering is not going to win any awards, but it should be good enough to get the job done. Time to see if I can make the firmware go.
PCBs are back from JLCPCB and looking very nice. If I do another batch I think I'll reduce the width of the edge fingers area 1-2mm so it's just a bit less snug in the card slot. Time to do some soldering.