alxlab-zone66x
commented
2 years ago Had similar experience with a Macintosh SE using a Power R Model 2703. Has a green bar on the right hand side. After going through all the open issue the green bar issue's cause is mentioned in issue #101 about having to do with FIFO (single line buffers) overflowing.
The scaling would probably look nicer with a 1024x768 preset since 512x2=1024 but it's already nice to be able to get any image at all lol. The image seems to be a bit unstable as well. I'm not sure if tearing is the right word. In the pictures it looks like the picture is wavy? Maybe the clock mod might fix that?
My friend and I are trying to capture video from a Mac Classic II (or really any compact Mac). We have wired HSYNC and VSYNC and Video (to Green) off the analog board to a VGA connector.
We picked up a GBS and did the mod on it in hopes we might be able to create custom timings since the signal is not standard, but we're only getting so far.
I found the other 'issue' asking about 22kHz support -- it states that it should work but it's 22.25 so I don't know if that's enough to throw it off. Here is the result we are getting.
The photo here is actually after we shifted the image right so the left side would appear on the left but there is clearly something up with the sync that the GBS isn't expecting. The monochrome signal is wired to the green input so the result is expected. Not sure if the the GBS has a way of dealing with that so I figured I could correct it after capture.
Below is some information I found on the timings: "HSYNC-Frequency 22.25kHz, 45µs period, 18.45µs low 59% PWM duty cycle VSYNC-Frequency (Refresh rate) 60.15Hz, 16700µs period, 180µs low 99% PWM duty cycle DATA 15.6672MHz, 512 pixels in roughly 32.8µs Signal has to be high while no pixels are sent"