I tried to reproduce the problem to give exact details but now it doesn't happen anymore, even after several restarts. What happened before was that the emulator would run at 10-12 Hz when limiting speed and at 200 Hz when not limiting the speed. Something triggered this and I don't know what. I turned speed limit on and off several times then with consistent results. Now when I try it works as expected, 50 Hz when limiting and 200 Hz when not limiting. We'll see if it turns up again later.
I ran Z64K yesterday and had some problems with the framerate when limiting it. Are you interested in that kind of feedback at this point or is it too early in development? Maybe you should start a thread to discuss the emulator willymanilly?
Good work on the resolution limit! I looked around for CGA signal information but that was harder to find. Anyway, lots of cables are sold using only the monochrome output to connect to TVs so I think PAL and NTSC standard signals are still relevant.
I'm a few hours away from San Francisco, and I have an extra C128! When are you arriving, and how long are you staying?
This is just too good to be true! I'm arriving next Friday, the 24th and leave the 3rd next month. I'm going on a business trip so I'll be busy most of the day Monday to Friday, but I'll not be working the weekend, so I could definitely meet up somewhere then. I'll send a PM.
I have found some info that explains the standard resolution values. According to www.batsocks.co.uk/readme/video_timing.htm, in a composite signal the blanking should begin 1.65 µs (PAL) before the hsync and be 12.05 µs long. With a 16 MHz pixel clock each pixel takes 0.0625 µs. So to get the left blanking character, take the hsync character position, subtract as many characters as needed to get roughly 1.65 µs less. The standard VDC values subtracted two 8 pixel characters, which is 1 µs. Then to get the right blanking character, add as many characters as needed to add 12.05 µs. The standard VDC values adds 25 8 pixel characters, which is 12.5 µs. For NTSC, blanking should begin 1.5 µs before hsync and be 10.7 µs long.