Posted By
Imperious
on 2014-03-30
07:24:24
|  Re: Suspected PLUS/4 Ram fault
Thanks Mik and Reto76.
At the moment I'll preserve them, all 3 are about as close to immaculate as they come, and all are working now.The only trick here in Australia was getting a step-down transformer as the power supplies are 110v AC, but that was only $23.50 for a 200 watt unit.
The 3 are all from the USA, and I have noticed that quite often they pop up in original boxes with all original documentation inside. 2 of mine are boxed with packaging intact, the other was the console only, but is still in great condition. I payed just over AUS $100 each for the boxed units, $65 for the other one.
I found out pretty quickly that there is hardly any NTSC games, 90%+ are PAL. This is likely why there are quite a few from the USA popping up on ebay. You have to wait for one with reasonable postage though, as it is all over the place, anywhere from $40 to over $100 which is too much. The plus/4 is easy enough to convert them to PAL, just replace the crystal with the correct 17mhz part and burn a PAL Kernal ROM, i bought a cheap clone of a Willem eprom burner for Christmas so that has proved an asset, was only $37 too.
I will be using my plus/4 sparingly as I am aware of how fragile the TED and CPU is. I came across a circuit here which is a diagram for making a 8501 replacement with a 6502, 6522, and some 74ls chips, so might give that a go at some point.
My work history is as an Electronics tech, but have very little engineering knowledge. I really enjoyed getting my head around this problem though, and same with the 2 c64's that I repaired last year.
|
