Williams Video connection question

shilmover

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All,

Trying to connect a Williams board to a regular arcade monitor (R-G-B-GND-Sync). The connector has 6-pins (R-G-B-GND-VSync-HSync). Do I just connect the 2 Sync together?
 
And remember - Wiliams games use positive sync. You have to either connect it to the positive sync input on the monitor, or invert the sync signal with a 7404 or similar.

-Ian
 
And remember - Wiliams games use positive sync. You have to either connect it to the positive sync input on the monitor, or invert the sync signal with a 7404 or similar.

-Ian

This is being connected to a Sharp XM200 (or whatever its called) monitor. How do I connect the 7404?
 
This is being connected to a Sharp XM200 (or whatever its called) monitor. How do I connect the 7404?

The 7404 is an inverter chip, it contains six seperate inverters. You can also use the 7400 NAND gate chip, wiring the gates as inverters, or any number of similar chips to do the same function.

The 7404 chip needs power and ground, so connect pin 7 to ground, and pin 14 to +5. You can use any gates you want on the chip, for example, hsync in to pin 1, inverted hsync out from pin 2, and vsync in to pin 3, inverted vsync out from pin 4.

-Ian
 
All,

Trying to connect a Williams board to a regular arcade monitor (R-G-B-GND-Sync). The connector has 6-pins (R-G-B-GND-VSync-HSync). Do I just connect the 2 Sync together?

The 7th pin on the willams video connector is +csync. Use that... if you need -csync, cut "W1" on the CPU board... that's what it's there for.


Connecting csync to hsync on the monitor only works when the monitor has a sync separator built in (many do). Connecting hsync to cysnc will only give you a rolling picture since there's no vsync information in csync. Shorting h/vsync only works when the drivers are open collector, which they aren't on williams -- but nobody was really expecting Dokert to know what he was talking about anyway.
 
The 7th pin on the willams video connector is +csync. Use that... if you need -csync, cut "W1" on the CPU board... that's what it's there for.


Connecting csync to hsync on the monitor only works when the monitor has a sync separator built in (many do). Connecting hsync to cysnc will only give you a rolling picture since there's no vsync information in csync. Shorting h/vsync only works when the drivers are open collector, which they aren't on williams -- but nobody was really expecting Dokert to know what he was talking about anyway.

I did notice that in the wiring (the 7th pin). I think I will build the circuit RetroHacker suggested as I dont want to modify the board (i need to test it on the test bench and dont want to put a 4900 up there).

Anyone know if this might be why I cannot get the video on my System I board to stabilze? (on the test bench)
 
Here is a link to a simple inverter made from a 7404: http://www.twobits.com/sync.html

ken

OK, got the picture to display now:
sync.gif
 
I did notice that in the wiring (the 7th pin). I think I will build the circuit RetroHacker suggested as I dont want to modify the board (i need to test it on the test bench and dont want to put a 4900 up there).
(on the test bench)

If you don't have a video inverter on your EZV, it won't display properly anyway.
 
Anyways... if you cut pin 5 of 4A and tie it to +5, you'll get -csync on pin 7, without effecting the polarity of the sync on 5,6 for use in a normal cab.

I normally just cut W1 and put a slide switch in its place so the sync is selectable on the boards I work on....
 
Here is a link to a simple inverter made from a 7404: http://www.twobits.com/sync.html

ken

Thank's Ken. That's perfect!

If you don't have a video inverter on your EZV, it won't display properly anyway.

Its actually the Sharp version, not the Sanyo which has the video inverter on board (one of the reasons I use that one :) )

Anyways... if you cut pin 5 of 4A and tie it to +5, you'll get -csync on pin 7, without effecting the polarity of the sync on 5,6 for use in a normal cab.

I normally just cut W1 and put a slide switch in its place so the sync is selectable on the boards I work on....

Good suggestion, thanks Mark!

Much appreciated everyone...
 
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