tech help

[hullfandan]

[ukvac] tech help
Does anyone know if there are any eproms compatible with the 4 rom chips on
the midway space invaders motherboard. If so does anyone know where I can
get hold of some?

Is there any special reason for the use of ceramic axial lead capacitors on
the section of the board with all the logic IC's or can these be replaced
with standard capacitors of the same capacitance?

Also should the 2mhz timing signal to the processor be a square wave? The
pulse I'm getting on my board is 2mhz but the wave is far from square.

Finally is there a "fixing arcade motherboards for dummies" website with
this kind of info on so I can stop bothering all you nice people

Dan

 

[John Bennett]

Re: [ukvac] tech help
Dan

You should be able to use 2716's and re-strap the board to accomodate them.
If you can't get a hold of the rom's then give me a shout and i'll send a
set down. As for the clock signal, as long as it's around 12V of the
correct frequency you should be OK. You should replace the caps with 0.1uF
ceramic caps.

Best of luck

Peter



DATA Imported from archives: originally posted by Peter Fyfe (peter@bombjack.freeserve.co.uk)