Anyone use an Extron VSC 500 or VSC 700?

[bcass]

I'm looking for a device that can sit between my MiSTer FPGA and my PVM so I can manually adjust horizontal / vertical position and horizontal / vertical size. This would be using the MiSTer analogue board for analogue RGB. I understand that the Extron ASC 500 and ASC 700 scaler / signal processors allow you to adjust position and size of an RGB signal. However, I am very cautious about purchasing as I can not find any soild info on possible latency created by these devices. I should note that I would be using 240p output. Can the Extrons just pass the 240p signal to the PVM whilst modifying the signal rather than processing it (scaling)? If these devices are not particularly suitable, then does anyone know of anything else that can adjust position and size?

[orange808]

Those are scan converters and they output 480i. Should be about a frame of lag.

I don't think that will work. I don't think they accept 240p or 480i input at all. The 500 and 700 models don't have any additional output options, they are exclusively 480i.

[bcass]

Damn. Is there anything else I can use to do this without introducing lag?

[Fudoh]

yeah, definitely not a solution for you.

I would forget about the resizing* and go for two-axis position adjustment only using this unit by Time Harvest:
https://www.youtube.com/watch?v=lxH2itK2w_k

* resizing requires you to either scale the signal (not doable at 240p) or to heavily tab into the timings by reducing/extending the front/back porch. Quite hard to do keeping the signal completely stable. Also only a very limited amount of devices that can actually do that to an analogue signal without digitizing.

[bcass]

I've read that those AliExpress devices deteriorate image quality. Also, positioning is the least important of my requirements, it's the size adjustment that I need more. I can do it all on my PVM, but it requires accessing the service menu (to adjust size greater than the normal menu allows), put PVM in standby, then turn back on, then change position in normal menu. It's a chore to do for every game, and would be a lot nicer if I just had a set of dials right in front of me.

[Fudoh]

you have to understand that external resizing isn't the same as using the beam adjustments on your CRT. Using an external resizing device doesn't change the area of the cathode rays are drawing, scanline sizing and position remains exactly the same, so you're working on a rather limited base line. I wouldn't try achieving anything like it on the vertical axis anyway.

[kitty666cats]

I'd suggest (for those games where you need to adjust size and position) just getting a PC CRT and outputting 480p w/ scanlines from the MiSTer. It will look just as sharp as your PVM, if not sharper. Super easy to adjust image size and position on a PC CRT.

[Guile]

You could also use an hdmi splitter and take the digital 720p or 1080p from the hdmi output on the Mister and then use an hdmi to vga converter for input to the Extron vsc.

The lag is a half frame so it feels pretty lagless.

[bcass]

I'd suggest (for those games where you need to adjust size and position) just getting a PC CRT and outputting 480p w/ scanlines from the MiSTer. It will look just as sharp as your PVM, if not sharper. Super easy to adjust image size and position on a PC CRT.

I don't have the space for another CRT monitor. The one I have already occupies a lot of space as it's 29".

[strayan]

Have you considered using a gbsc?

[thchardcore]

Do the Extron 201/203 units reposition without lag?

[bcass]

According to feedback I obtained from reddit, the Extron units are not suitable for this task as they can only output a minimum resolution of 480. I'd be very interested in there is any other hardware than can be used for my use case.

[bcass]

Have you considered using a gbsc?

Is this just another scaler? What is the output resolution? Can it be used for adjusting v / h position and size?

[orange808]

Google MiSTer custom modelines. You should be able to program the MiSTer to directly output a good video signal for your display.

Before you ask: No, we can't do that for you. I can't see your display. You should be able to manipulate the front and back porch values a bit without losing sync. Try to leave the totals alone. The porches are the blank areas on the four edges of your image. The syncs are where the mechanical electron gun resets horizontally (and "down") multiple times while scanning out before it (finally) resets vertically (back to the "top") to scan out a new image/field/frame.

I bet the MiSTer can natively output what you want.

[bcass]

That sounds interesting, but would that be per-core or a global configuration for all cores?

[orange808]

That sounds interesting, but would that be per-core or a global configuration for all cores?

I think you can do it by core.

Below is a link to a repo has modelines, but they aren't for 15Hz displays. You'll find the repo expresses similar frustrations to your own, but with other displays. Proof of concept that others are using modelines to get what they want directly from the machine.
https://github.com/mrchrisster/MiSTer_Integer_Modelines

This repo contains resources to help you create your own.
https://github.com/atrac17/Integer_Video_Modes

[bcass]

Thanks for the links, I will do some investigating.