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Vercus
November 21st, 2009, 09:59 AM
Well, I'm about ready to give up on these Northstars. I just don't have the patience or desire to deal with them. I've got one system running, but it's extremely flakey, and can't write to any floppy drive reliably without crashing. I've tried no less than SIX different floppy drives, and two different disk controller boards, and always the same result. I've tried dozens of disks as well, but no luck. The memory board was recapped and tests out as 56K, which seems odd, as I was told it was a 64K board. Both floppy drives have been lubed with lithium grease and work fine in my 486 PC.

I'm not really sure what to do at this point, as they've been just a source of irritation and stress I don't need or want. Pretty much, unless I can get a quick fix, I'm going to get rid of them. I won't junk them without offering them to someone on here first.

-Jon

Dwight Elvey
November 21st, 2009, 11:08 AM
Well, I'm about ready to give up on these Northstars. I just don't have the patience or desire to deal with them. I've got one system running, but it's extremely flakey, and can't write to any floppy drive reliably without crashing. I've tried no less than SIX different floppy drives, and two different disk controller boards, and always the same result. I've tried dozens of disks as well, but no luck. The memory board was recapped and tests out as 56K, which seems odd, as I was told it was a 64K board. Both floppy drives have been lubed with lithium grease and work fine in my 486 PC.

I'm not really sure what to do at this point, as they've been just a source of irritation and stress I don't need or want. Pretty much, unless I can get a quick fix, I'm going to get rid of them. I won't junk them without offering them to someone on here first.

-Jon

Hi
First the reporting of 56K is about what I'd expect. As you should already
know, the N* has ROM and some I/O at the higher addresses.
This would reduce the size seen by the processor.
Did you run an extensive memory test or just the simple one to
see if there was RAM.
Do you have an oscilloscope? There is much that you can still do.
Just board swapping is not all there is to trouble shooting.
Take a deep breath and think about what could be failing.
You mentioned that the RAM board you were using is a 64K.
Could it be that it is being selected when the N* is accessing
the disk drive. Most memory boards are suppose to recognize
the phantom signal ( I think that is what it is called ) and not
drive the bus when it is active. It might be that your board
is clobbering the disk controller board ( which I'm told is
memory mapped ). You might also try jumpering the memory
board for 48K and see if that makes a difference.
Dwight

billdeg
November 21st, 2009, 03:58 PM
I sent you a PM if you'd like to get together to try to fix, I also live in PA.

Take a look at this thread on my web site, it sounds like a problem I once had is similar to what you describe, and I have documented the solution here (read the whole thread):
http://vintagecomputer.net/browse_thread.cfm?id=111

Bill

Dwight Elvey
November 21st, 2009, 09:07 PM
Hi
How did a working system get the dip switch socket
moved? Inquiring minds want to know.
Dwight