shmups.system11.org

Hi,
I actually made a computer outputing 15khz signal for émulation purpose coupled with an extron rxi for combining the sync to a crt,i can adjust the position of the picture with the extron but not the size .
Is there any kind of équipment that i can add to the chain with control on the HV size of the Picture please.
The goal is to don't have to adjust the picture on the TV each Time i change of game.
Thx.

No, that's not possible on CRTs. On the vertical the line mapping is fixed and you have to change the size on the display itself, which alters where the actual cathode ray hits the mask. The horizontal size can be altered by changing the sync width and timing values, but is usually also much easier done using the TV's controls.

If you don't mind the picture quality you can use a 31khz output from your PC into an Extron VSC. During the scan conversion you can change size and position, but of course it completely screws your line mapping.

Ok thx for the answer.

Out of interest... how may one go about altering sync width and timing values?
I see the LM1881 has an Rset option to adjust some timings, but I am not really following exactly the input and effect...

I'm interested in altering the picture width from an IGS PGM unit...

https://photos.app.goo.gl/rUXSgyW2YPbwp0v73

https://photos.app.goo.gl/5RN7lUkzlnEGNvbf2