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Robert Bullock
 
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Default Report: Analog CGA monitor

I bought a Samsung CD1251F/38NA that works with CGA res with only a sync
seperator circuit. On the back is a switch you must put into Mode II. Mode I
is probably digital TTL CGA I guess. I found the sync seprator at:

http://www.lupinesystems.com/articles/syncsep.htm It does /HSYNC, /VSYNC,
VSYNC, HSYNC and more but that'll do.

Works great, and it's a 12" so it's great for the bench. Now everyone go
drive the price up on eBay. I paid $4 for mine.

Parts were $10, but I bought a 4x4 pad per hold prototype PCB and it only
took about a 2x2 square for the circuit. I used component legs and solder
bridges for the traces except the small ones under the LS00's that went leg
to leg. For those I used tensioned 30 guage stripped wrapping wire. Solder
one end, stretch it tight, solder the other end so it doesn't wander around.
Hot glue it on the bottom for extra credit.

Quality is the enemy of production. I'm adding that to my sig.

You want to use pins 6 and 11 on the LS00 with all the outputs. For this
monitor, positive Horizontal and Vertical sync. Beautiful except on my
machine, I get crawl on some colors from RF interference. See my previous
posts about Galaga in particular.

Socket your LS00's in case you screw up, plus the heat is only on the
socket, etc.

Now back to fixing my Ms Pac pile.

Pay it forward.

keywords for google. 74LS00 15KHz standard arcade resolution CD1251 CD1251F
38NA 2
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Homepage - http://members.cox.net/rcbullock/ 'It's lamer than Spaeth's!'
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