#CIA's and stuff
10 messages in this thread
I opened up my 2000 to make the CIA switch. I had to remove the mounting
for the power supply and disk drives to find the chips. This meant that I
had to unplug the disk drive bus and power supply bus.
To make a long story short, after I switched the CIAs and was plugging the
disk drive bus back into its plug, I noticed that a pin was missing and
that the remainder of the pin was inside the socket.
I tested the CIAs to make sure that they were definately not the cause of
my problems. I then opened the computer up again to see if I could fix the
pin in the disk drive bus, but I had no luck…I think the pin is too
short.
I think it is pin #4. The male connector on the printed ciruit board has
the missing pin on the left side, second from last (closest to the back of
the 2000). I think this pin is indirectly connected to the Gary.
My belief is that when the previous owner of my A2000 replaced the Agnus,
the guy at store snapped the pin. He probably tried to fix it like I did
to avoid replacing the socket, tried the computer and thought it was okay.
Sigh…I guess I must ask my Dad to replace the socket. I'm not that good
with the soldering iron yet. My last project (an audio digitizer) looks a
little metallic! I guess I should try anything myself on the mother board
Chris,
Well…it's one of 4 possible pins (I forget the orientation of the
connector so don't know what the pin order is)…
It's either pin #3 (which is supposed to be missing…it's the
"key"), pin #4 (which is the motor on/off control line), pin 31 (data
ground) or 32 (sideB…which head to select).
Memory tells me it's pin 3 (but my memory has been known to be
wrong). If so, that's not a piece of the pin in there…it's a "plug" so
you can't put the connector on wrong. That's why pin #3 is missing…so
the plugged socket will fit over it.
Don
My delete key sometimes doesn't delete, but I guess it is just common use
of both the space bar and the delete. I'll have to get the contact cleaner
inside my keyboard.
I'll keep that in mind the next time I take out my CIAs. I wouldn't want
to zap both of them if they aren't the source of my problem.
I suspect that it is the empty pin too, but I'll double check by trying to
trace where that pin leads. Sigh…If it isn't the CIAs, nor a
pin….Could it be my Gary? Is there any way to check?
Chris,
The only way I know to check a GARY chip is to swap it with a known
good one.
Don
I tried my version of MessyDOS on my Dad's A500, and it locked up his
computer like it did mine. I'll recheck my Mountlist entry just in case I
erred someplace. However, I'm still concerned. I bought a game while I
was done in the US a few months ago. I brought it home and tried it on my
A2000, but it did not work. I tried it on the A500, and it did work. The
game is "AD&D Heroes of the Lance". The main difference between my A2000
and my Dad's A500 which I think could possibly effect the booting of this
game is that mine has the 1 Meg Agnus and the flicker Fixer, while his
doesn't.
BTW, is there any difference whatsoever with an external A1010 drive and a
stock internal Amiga 3.5" drive?
Also, I would like to know if it is safe to open the cases of my internal
drives to clean them out. While cleaning the rest of my computer, I
no
ticed a great deal of dust inside the drive, and I can only clean it if I
remove the metal shielding.
Finally, if you haven't noticed, my space bar no longer gives me double
spaces when I only press it once. I opened up the keyboard and gave it a
cleaning, pulled off a couple of keys and sprayed some contact cleaner onto
the connections inside. Even the delete key hasn't been acting up…..yet!
BTW, thanks for all the help! (Do you, by chance, write for AmigaTech
Journal? I'll be getting a subscription soon, and I thought it would be
nice to see some Transactor authors in it, for familiarity sake!)
That game might require some FAST RAM, and you may not have any
FAST RAM in your A2000 while your Dad may have FAST RAM in his A500. Your
A2000 came with 512K CHIP and 512K FAST. Adding the 1 Meg AGNUS made your
A2000 all CHIP. That presumes no addon RAM boards.
The A500 comes with only 512K of CHIP, but if you add the A501 to
bring it up to 1 Meg…you'll end up like your A2000 before the mod….1/2
and 1/2.
Some programs have been improperly written assuming FAST RAM exists
which is an improper assumption.
Presuming you are careful, and know what you are doing…sure, you
can take the metal shielding off the drives to clean them. Just don't bump
the heads or turn any adjustment screws. Commodore has bought drives from
many manufacturers over the years. Electrically, they may be identical,
but physically they can be different.
I'm considering getting back into writting again…but nothing
definate yet.
Don
My A2000 does have fast RAM…2 Megs to be precise. Could th{ Fatter Agnus
be interupting or disturbing part of the code? I noticed that the game is
not on a standard AmigaDOS disk (however, it does copy with the Amiga Copy
program supplied with Workbench). Could a possible drive alignment be the
problem for AD&D to not load?
Would you know if there is a Strategic Simulations Inc. representative
online here? Perhaps he or she would know of a solution.
Chris,
Presuming the chip itself is ok…then no, I know of nothing at all
that the 1 meg vs the original 512k AGNUS could do that would cause you any
problems.
Yes, drive alignment could cause you problems…but I'd suspect the
problems would show up on more than one disk if that were the problem.
No idea if anyone from SSI is around here.
Don
Chris,
I'm not absolutely certain, but I think that pin was supposed to be missing
– that it was like a 'key' to make sure you got the socket attached
correctly to the correct pins. It was a matter of considerable discussion
a year or two ago, and this is the way I remember it.
Betty
At any rate, it didn't solve my problem, so I must search for another
reason why my internal drives won't write to IBM disks using MessyDOS.
Actually, I use, as aid, the direction of the ribbon, and the little arrow
lining up with the 1 (the arrow on the plug, and the 1 printed on the
board) to help orient me. If I figure I may make a mistake and put
something in backwards, I draw a diagram. Better safe than sorry!