16 Jan
2013
16 Jan
'13
12:10 p.m.
On Jan 16, 2013, at 12:49 PM, John Robertson <pinball at telus.net> wrote:
People have replaced 4116s with 4164s after cutting
the -5 and +12 supply lines to the RAM banks to improve reliability:
http://www.robotron-2084.co.uk/techwilliams4164.html
The above link is for converting a video game motherboard power connector to eliminate
the -5/+12 lines without cutting lines on the motherboard.
As I mentioned in my other email (which might not have made it through
yet), that method works as long as the -5 and +12 aren't used elsewhere
in the system, and as long as the +5 can be safely rerouted to the +12
rail. That is true of Defender (because the regulated +12v and the -5v
are only used on the RAM; the audio board makes use of the unregulated
+12v as do some others), but is less of a safe bet on more complex
systems. Really handy on most early Williams boards, though. :-)
- Dave