I've seen pictures of the back of the PCB, but not the front, so here are some with epoxy removed. This is my Reprint Edition, the latest release, just got it a few weeks ago. The rom itself is an exact match of the Revision B that is already floating around.
Interesting for the first version and the reprint. They had epoxy on everything. I imagine they decided since the game is dumped already there was no point.
[FONT=Verdana, Arial, Helvetica, sans-serif]And here is rev2 (picture found some years ago on emu-land.net boards, courtesy of HardwareMan) [/FONT] Same chips, different design. I heard the new design had issue with model 1 consoles on power-on. I wonder what all those resistors connected to i/o pins on the new board are for ?
It has issues with the Non-TMSS Model 1 systems. You are greeted with a black screen every time you power it on, you must press the reset button after power on for the game to work, each time.
The EPM240 is a 3.3V part and to interface it with 5V signals you are supposed to enable the internal clamp diodes and use an external series resistor. I guess they didn't bother doing that one the original release and just directly connected the bus lines to the CPLD IO. This is something you can generally get away with (although the datasheet doesn't approve of it), but it's possible that it will result in long-term reliability issues.
The EPM240 actually doesn't have clamp diodes, so the resistors serve no purpose but to increase the rise-time. 3.3V-only CPLD may have gate oxide that can endure months of 5V, but they will eventually fail. There's so much bad engineering in homebrew...
Interesting - I had only ever used the EPM1270, and that did have them. Seems like a strange omission from the smaller parts. My guess is that the figured that the 68K would only pull things up to about 3.8V anyway, so it should last long enough...
