Re: ROM 3 //gs issues

[Mitchell Spector <mitch2gs@hotmail.com>]

a2aviator@gmail.com wrote:

>I have had some voodoo issues with early ROM 3 boards.
>
>Way more than once. Way more than my one realm.
>
>The earlier ones look like more goldish/copperish than the deep/shiny
>green ones.
>
>They're just flaky. Sometimes removing the bottom FCC shield fixes it,
>other times.. they just.. want to be bent in the middle. I've applied
>rubber feet under and put them back down on it, etc. They're just
>flaky. I think it's a manufacturing problem.

    I concur. My original ROM 3 motherboard has the gold traces
and used to periodically go dead during a cold or warm boot (no
sound, just a black screen). You'd have to repeatedly tap the front
extension tab on the front of the case to "wake" it up. Or do the 
old Apple III 3 inch drop trick heh.

    These boards also have that infamous glitch with the programmer
CDA's always active. I visited one of Apple Canada's main repair
centers years ago and saw more than one machine with this glitch, 
mine isn't unique. Not sure if it was just the gold trace boards affected,
the source of the problem was a certain batch of DRAMs used for 
Slow RAM. At cold boot a certain bit would have the wrong value at 
a specific location--David Empson discovered it with some back and 
forth tests we did comparing his ROM 3 with mine.

>The best ones seem to be the ones that are shiny, bright green masked
>with two 28 pin ROM sockets and the worse ones tend to be the ones
>with two 32 pin ROM sockets and a dull near copperish/brown look.
>
>Most of those old ones have EPROMs in them too.

    So there were three different variations of the ROM 3 board then,
right? (if there are more, I haven't seen them yet). :)

Mitchell Spector