#Memory HELP!
8 messages in this thread
Jay,
I see you already have a good tip in another reply, but here are a few more
thoughts.
Sometimes (depending on the exact failure mode), you can 'bridge' a chip by
using a good chip and just sliding it down over the pins of one that is
soldered onto the board. This puts the entire chip in parallel with the one on
the board, and given the right failure mode, can cause it to 'take over', and
work fine. You don't want to leave it there, but for testing purposes it's
fine.
Calling CBM might be a way to go, though I don't know who might be the best
to call there. I'll try to find out from our local repair people, what the
layout is.
Good luck! -larry
Larry, your idea of placing a new chip directly over an exsisting chip sounds
great, my only concern is that how "dangerous" could this be? I wouldn't want
to fry the whole board! BTW, I did try that tip from Rob Salmon, unfortunatly
it didn't work, but I appreciate the idea none the less.
If I were to try and bridge the chip, would I just put the new (good?)
chip directly over the chip to be bridged, making sure the all the pins lined
up, and then power-up and run the test? If that's it then I can handle that. I
start getting lost with addresses and allocation routines and memory map
diagrams, but I think I can handle chip bridging!
Thanks agiain for your help, Jay
jay,
Yes, that's all there is to it. Just make sure that the pins not only line up,
but that the chip is the 'same way around', otherwise is stir-fried chip time.
-larry
Larry, Yeah, I guess making sure they're both lined up the same way would be
important, else I'll be using the board as a rather nifty, if somewhat
expensive, serving tray at my next party! Really though, it's a good idea and
since Dean Brown has given me something to go on, that might be the only way to
isolate the offending little bugger. With the rather limited info I provided,
Dean has narrowed it down to one of 16 chips, which is a hell of a lot better
than one of 64 chips! The only thing I was concerned about is if the memory
allocation routines are the same on the 500 as they are on the 2000. If they
are then it's no problem, but if they're different then I'll have to test the
board in a 2000. I know it's not the fault of my 500 this time, but, it's
really been somewhat of a nightmare trying to expand this thing. The hardware
situation for the 500 is very limited in selection, and trying to find the
product you've decided on is next to impossible. My advice to anyone is that if
there is the remote possibility that you'll want more than 1 meg or that you'll
want a Hard Drive, get a 2000.
-Jay
Jay, I found out the hard way that the best way to expand a 500 beyond one
board was to get a 2000. I had a SubSystem 500 and when I just had the 2052
memory board plugged in, everything would work fine. But when I added the 2090
controller, you can't believe the problems it had! So after about 2 months of
fooling around with the damn thing, I threw the SubSystem in the closest and
ordered a 2000. I've been much happier since then :^).
John
John, I know just how you feel. The frustration at *trying* to expand the
500 using 'makeshift' products like the Subsystem have driven me to the point
that you have already reached, namely selling the 500 to get a 2000.
I don't mean to badmouth the Subsystem, after all, it does give you an
alternative by allowing you to use SOME 2000 cards, BUT WHICH ONES???? That is
a question that NOBODY can answer, people using the same card(s) report
different problems or no problems at all, sort of hit and miss. This is NOT
adaquate for me and, evidently, you. So, unfortunatly or fortunatly depending
on how you look at it, I will be selling my 500 and buying a 2000.
Let me make it clear though, there is nothing wrong with the 500. It was
just never designed to do the things we are now asking of it. It was designed
to accept ONE expansion board, which it will, but if you try to go beyond that
you will (?) have problems. The 500 itself has never given me a day of trouble,
but, my requirements have now gone beyond its designed capacity for expansion.
-Jay
I agree with you Jay, the 500 is a nice computer, and when I had mine, was very
reliable. But we both needed to expand it beyond what it is really capable of.
I'm sure that with the proper buffering and termination, an expansion chassis
can be made for the 500, but the cost would put it out of line. I guess this
can be a lesson to anyone thinking about buying an Amiga. Think about what you
would like to add to it in the future, and if it involves more than one board,
get a 2000. I really like mine so far, and will be adding a 71 MB hard disk
soon. I already have a 20MB, but that filled up in a hurry :^)
John Gager
John, 71 MB should be enough for a while 😉 I have a 63 MB that's about
half-full, so I still have a ways to go, but, always lookinghead, I am
already pricing out an 80 MB in the Shopper! Really though, I love my 500, it
has taught me alot and never given me a moments trouble, except when I started
to expand it, and that wasn't IT'S fault.
So, what kind of deal did you get on your 500? Did you trade it in or sell
it? I recently saw an ad in AmigaWorld (M.C.S.) that offered trade-ins, so I
called them up. Here's the deal- they take your 1 meg 500 and $1100. and they
send you a 2000, you keep your monitor, but they will take an external drive
even-up for an internal one. Sounds pretty good to me, I did some quick
calculations and found that it would be almost identical to selling the 500,
1084, and 1010 privately, and you don't have any hassles trying to sell it.
What do you think?
-Jay