#2.04 A500 install woes
5 messages in this thread
Here's some more insight into my 2.04 installations on my A500. As I
stated before the new rom chip works fine with the cover and shield off. I
put the cover and shield back on and it doesn't work. I don't have the
same problem with the 1.3 rom.
Today I tried something new. Took off the cover and shield, put in the
2.04 rom, tested it. It worked fine again with the cover off. Then I HELD
the shield about six inches over (not touching) the main board and it would
not boot again, just a black flickering screen with no drive click. Being
of a scientific mind, I tried the experiment with the shield held over
various parts of the motherboard, and found the problem only occurs when
the shield is over (not touching) the Gary chip, if its over any other part
no problem. It can't be that the shield is shorting anything, its not
touching anything.
Now I've had a 1 meg Agnus on board for about a year, and a Commodore
authorized technician performed the necessary surgery on Gary's 32 pin.
I've never had any problem with the Agnus, the Gary or the 1.3 rom, but I
wonder if that has anything to do with my problem.
please help. Dan Cole
Dan Cole
Boy that is a bizzare problem! Out of curiosity, why don't you just run
with the shield not attached? Does it do anything other than reduce
interference? Or is the interference too bad with it off?
–jp–seattle–
I think it also holds the keyboard up. Dan Cole
Dan,
I've been running my 500 ,without the shield for about a year now. It
doesn't hold the keyboard up. The keyboard is rigid enough to stay up by
itself.
Rodger
– via Whap!
I have heard of this happenning on other people 500's, and its a problem
with the floating pin on the Gary. Gary is a CMOS chip and should not have
any floating pins to work correctly! CMOS is a little wierd that way. As to
why its works on 1.3 and not on 2.0, is that somehow 1.3 is less sensitive
to either timing or voltage problems. The only way to fix the problem, is
to get pin 32 back in, and do the trace cut and jumper mod to get 1 meg of
chip back.
BobC