Topic: Ironman Ivan Stewart's Super Off Road-no Sync  (Read 1760 times)

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Offline Cosmic Alien

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Ironman Ivan Stewart's Super Off Road-no Sync
« on: May 10, 2011, 08:04:23 PM »
Hi all
I have on my test rig a Super Off Road pcb and have been making a Jamma adaptor but i notice it uses Cinemat System and the H/V sync signals are separate,can anyone tell me the best way of converting these signals to comp sync for Jamma,i have tried combining both signals in to a 74LS08 without success.
Someone has told me i may need to invert the signals with this system,can anybody confirm this?
thanks -Steve.

Offline porchy

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Re: Ironman Ivan Stewart's Super Off Road-no Sync
« Reply #1 on: May 11, 2011, 07:48:24 AM »
Hello and welcome to RCM.
Have you confirmed that you have any sync at all? If you can, check this with a scope.
Im not sure what polarity sync Super Off Road gives out but for JAMMA it is active low. Using an 74LS08 should work but if you need to invert that signal you can add an 74LS04 in there first.
Just looking in the manual now (which has schematics in the back of it) it was a couple of points which it calls "parts most likely to fail".
It states:
Video (color or sync) - 1st - 7405 or 74s05 @ location M-U24 (M stands for main board)
                                 2nd - 74LS374 @ location M-U37

IF you dont already have it I can send you this manual.
Let us know how you get on

Offline Cosmic Alien

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Re: Ironman Ivan Stewart's Super Off Road-no Sync
« Reply #2 on: May 12, 2011, 12:06:43 PM »
Hi Porchy
Sorry i should of mentioned this i know,i do appear to have what i see as strong sync signals on both H/V sync and i do have a copy of the manual,as i purchased this in a joblot it it quite possible to be faulty but then again being a somewhat dedicated board it may of been salvaged from a wrecked cab or just lost favour with an arcade owner and the pcb dumped in a box.
I will run both H/V signals through a 74LS04 and then into the 7408 and i will take it from there and let you know,although can i not just invert the combined signal using the 7404 after the 7408? or should i invert both signals before they are combined?,i will prob try all ways anyway  ;D
I have a Gladiator board on the test rig at the moment so when i have dealt with this i will swifty retrun to looking at offroad.
« Last Edit: May 12, 2011, 01:10:32 PM by Cosmic Alien »