Hi All,
About a year back I managed to get my hands on an APple IIe International computer. It came with an Apple II HDMI card so I have been using that for video the entire time.
Recently I went and bought an ESP32 to play with but after connecting it up, the display just showed flashing @ symbols. When I connect composite directly without the ESP32, it does the same so it looks to be something with my composite display. A diagnostics did not report any issues with the machine.
If anyone has any suggestions on what to look at further I would be greatful. From what I have read, it could be the Character Generator ROM or power supply (it is using an ATX to Apple IIe adapter Pico (picorc.com).
Thanks.
Yes, unfortunately ever since the VGA and HDMI cards came out, some unscrupulous people have been using them to pass Apple II machines with broken video as perfectly working ones. Because these cards completely bypass the motherboard's video generation circuitry, you only find out when you try to use the composite output.
There could be a number of reasons why your Apple IIe composite video is not working, but the power supply is not among them. However you can still use your ESP32 SoftCard with a separate composite monitor or TV, since the card generates its own composite video signal.
As CVT notes, you can use the composite out from the ESP32 Softcard. That's what I do, I hook that to a Compisite -> HDMI converter and then run that into an HDMI switcher which the A2VGA card in that //e is connected to the other side of. I have to switch the HDMI switcher, but it gives me higher quality output for the native //e as well as a really nice output from the ESP32 that way. The video on that //e does work, but the A2VGA produces a better native output than the composite through an HDMI converter or directly into the Emerson TV I have all that hooked to. The Emerson is nice for use on a //e and other retro use because it has two HDMI inputs and composite and split video in as well. Most of the newer LCD screens don't have all those inputs anymore.
Thanks for the replies and it is a little sad to hear this has become semi common in recent years.
Call me weird but I hate knowing that my Apple IIe isn't working 100% and I would love to get composite going again. I had also recently got my hands on an Apple composite colour monitor to use for that 'authentic' experience but I guess I will build a bridge and get over it for the moment and stick with the HDMI card + Composite out on the ESP32 side and see what fun I can have with the ESP32.
If you essentially have a stable picture over composite it's unlikely to be a IIe power supply issue. Distortion like the example below can be PSU related, even something as simple as a dislodged (IIe) PSU connector.
Apple IIe composite distortion PSU related
This looks a lot like a problem in the CRT monitor, possibly a bad electrolytic capacitor. Something similar can also happen when the ground of the RCA video cable is not making good contact with one of the video jacks.
I agree, it definitely looks similar to what I've seen with old CRT monitors when capacitors are going bad. Bad connections in the NTSC connector can also cause weird distortions, so it is a good point o liminate that as a possibility first too.