OSSC on a Macintosh SE/30

[xpc4owner]

I rigged a VGA cable out of my Macintosh SE/30 and ran it into the OSSC. Those old macs run a 512×342 Black&White (1 bit color) resolution. The OSSC handled it okay! My settings ended up as:

(22.24kHz 59.78Hz)
(Under 400p settings)
H sample rate 704
H synclen 14
H backporch 164
H active 512
V synclen 1
V backporch 29
V active 342

384/400 Scaling: 2x (monitor won’t sync on bypass settings…)

The picture fits perfectly and looks like [almost] pixel perfect scaling, so the moire is minimal, but the signal’s a little noisy/wavy. I’m still on 0.81. I noticed there is a an update to 0.82 and it has some 360p settings so i may take a look as thats closer to the native 342 vertical resolution. Otherwise, anyone have any thoughts on what I might do about a noisy signal? When i hook VGA directly up to the lcd monitor the noisiness goes away but it has a bad scaling algorithm so theres all kinds of moire patterns. Leads me to believe the signal is clean, though, and its just a sync issue.

I also run my Apple II GS and IBM PC (EGA) thru this as well as pc-98s and a lot of usual console stuff. Great device!

[BuckoA51]

Very cool, did you try playing with the sampling phase?

[xpc4owner]

I played around with the sampling phase and that got rid of most of the waviness after all. There’s some issue in the capture/circuit after all causing that vertical line down the 1/3rd mark, but it’s probably good enough for me for now. I tried messing with all the other timings/settings and couldn’t get anything better than what I currently have.

[Anonymous]

Wow cool. I have an SE30 and never even thought of doing this. Seems like a fun thing to mess with.

[Author]

Posts

[xpc4owner]

I rigged a VGA cable out of my Macintosh SE/30 and ran it into the OSSC. Those old macs run a 512×342 Black&White (1 bit color) resolution. The OSSC handled it okay! My settings ended up as:

(22.24kHz 59.78Hz)
(Under 400p settings)
H sample rate 704
H synclen 14
H backporch 164
H active 512
V synclen 1
V backporch 29
V active 342

384/400 Scaling: 2x (monitor won’t sync on bypass settings…)

The picture fits perfectly and looks like [almost] pixel perfect scaling, so the moire is minimal, but the signal’s a little noisy/wavy. I’m still on 0.81. I noticed there is a an update to 0.82 and it has some 360p settings so i may take a look as thats closer to the native 342 vertical resolution. Otherwise, anyone have any thoughts on what I might do about a noisy signal? When i hook VGA directly up to the lcd monitor the noisiness goes away but it has a bad scaling algorithm so theres all kinds of moire patterns. Leads me to believe the signal is clean, though, and its just a sync issue.

I also run my Apple II GS and IBM PC (EGA) thru this as well as pc-98s and a lot of usual console stuff. Great device!

[BuckoA51]

Very cool, did you try playing with the sampling phase?

[xpc4owner]

I played around with the sampling phase and that got rid of most of the waviness after all. There’s some issue in the capture/circuit after all causing that vertical line down the 1/3rd mark, but it’s probably good enough for me for now. I tried messing with all the other timings/settings and couldn’t get anything better than what I currently have.

[Anonymous]

Wow cool. I have an SE30 and never even thought of doing this. Seems like a fun thing to mess with.

[Author]

Posts