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VGA questions

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Hello there,

I have a computer with analog interleaved video output (monochrome, two vertical frames to get full screen).

Also are available separately Vsync, Hsync and video signals. Hsync is ~15625 Hz and Vsync is ~50 Hz.

My purpose his to use a vga screen instead of a tv.
I have to invert sync signals and put video into 0 - 0,7 V range, that s easy.

My question is about the interleaved signal and the frequencies. Will this work on a vga screen ?

Thanks for help.

I recall from the old days having an option for 1024x768 interlaced on VGA. So interlaced signals on VGA are possible.
However, if this particular signal works, I'd suggest to look at the manual of the monitor what signals it accepts.

You are S.O.L unless your 'VGA' screen is actually a multisync monitor supporting legacy CGA and EGA standards or RGB or component PAL/SECAM.   You'll find VGA timings here:
Please note the lowest line frequency is 31.778 KHz.

Therefore you'll need a scan rate converter to have any chance of success.

m k:
There were two kinds of multisyncs, VGA multisync and real multisync.
VGA multisync goes up but not down from standard resolution.

If memory serves.
NEC Multisync II is the real one.
NEC Multisync 2A is not.

Possibly all NECs with rounded corners were real and squared corners were not.
I'm quite sure I had a Multisync XL with BNC connectors and other end was DB9.

I think the Multisync will work but the picture shifts across the screen, the 2 is much better.

Also the Sony 1402 will work, but been a long time since I tried it, still my DOS VGA monitor.


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