RGBTOHDMI understands the Lisa video signal

[ried]

+1, Rick that is awesome. Any possibility this might help to get it working with 3A ROMs and the screen mod?

[bmwcyclist]

For the digital RBGtoHDMI interface cable, I brought out the TTL signals from the Lisa MB.

What rgb2hdmi profile do you use?

[Lisa2]

What rgb2hdmi profile do you use?

This is the one that I used:

https://texelec.com/product/rgbtohdmi-ttl/

Rick

[bmwcyclist]

For the digital RBGtoHDMI interface cable, I brought out the TTL signals from the Lisa MB.  U1 ( LS123)  pin 6   (VID) to IBM CGA pin 4 ( Green ), U1 pin 3   (Vsync) to IBM CGA pin 9 ( Vsync ), U1 pin 8   (Hsync) to IBM CGA pin 8 ( Hsync) and ground.  Works perfect!

Rick

Rick, I finally got everything together to do this, and I realize I am missing some information.

1. Your instructions indicate using Pin 3, 6 and 8 on U1/LS132. Your photo only shows 3 and 8 in use.

2. You show 2 soldered wires on the board, one I can see is likely ground (white), but what is the blue wire? Is this the one that would have come from Pin8?

3. Looking at the CGA connector, I see the blue and white connectors going to the same (connector) pin 8. So I am assuming this is an alternative to Pin 8 on U1? Is there another location to get ground using a mini probe rather than soldering?

Thanks!

Thanks!

[Lisa2]

Connect it like this:
74LS132      CGA
U1 pin 3 --> DE9 pin 9 (Vsync)
U1 pin 6 --> DE9 pin 4 (VID)
U1 pin 7 --> DE9 pin 1 (GND)
U1 pin 8 --> DE9 pin 8 (Hsync)

Note: I am not responsible if you blow up your motherboard... 

Rick

[bmwcyclist]

Connect it like this:
74LS132      CGA
U1 pin 3 --> DE9 pin 9 (Vsync)
U1 pin 6 --> DE9 pin 4 (VID)
U1 pin 7 --> DE9 pin 1 (GND)
U1 pin 8 --> DE9 pin 8 (Hsync)

Note: I am not responsible if you blow up your motherboard... 

Rick

Excellent, thank you. (except perhaps of course the disclaimer!  )

[bmwcyclist]

Ok, bought the same model RGB2HTMI wired it up.

Can you please share your settings?

I am getting a distorted green screen even after auto sync.

[AlexTheCat123]

Ok, bought the same model RGB2HTMI wired it up.

Can you please share your settings?

I am getting a distorted green screen even after auto sync.

Is your Lisa screen modded by chance? That looks a lot like what you get when you hook a screen-modded Lisa up to an RGBtoHDMI; I've never been able to tweak the profile quite right to get it to work with the screen mod.

[bmwcyclist]

Well it has H-roms.

I have never seen a screen mod but from the drawings in the Sun Remarketing repair guide it looks like mine does not have the mod.

[AlexTheCat123]

Yeah, the H ROMs mean that you don't have the screen mod, so we should be fine there. The only other thing that immediately comes to mind is the profile selection on the RGBtoHDMI. Did you actually select the Lisa profile (I think it's called "Apple Lisa TTL") in the RGBtoHDMI's config menu, or did you just turn it on with the stock settings? Looking back at your image, the display should be white not green if the Lisa profile is active, so I think that might be your problem.

[bmwcyclist]

OK, I didn't think I'd need to do that because of the wiring off of the chip instead of going out the RCA video Jack on the back.

I figured (wrongly) that I would just have to do the auto sync.

[bmwcyclist]

Ok! we are good!

I will take pictures and do a walk-through for posterity.

1. wired up to CGA port as per Rick's design
2. Attached to CGA to HDMI version of RGB2HDMI
3. Selected LisaTTL profile (at this point, you can see the screen but wavy)
4. Checked Genlock
5. AutoSync

It actually looks a lot better than the screenshots, they get what I think is a moire' effect when I downsize them.