9 Dec
2010
9 Dec
'10
2:58 p.m.
It would be very useful to know if this is a floppy
controller error or a
hard idsk cotnroller error.
Yes, I'd like to know that myself!
Should a Lisa 2/10 be able to boot from the floppy
drive if there's no
hard drive connected? If so, it would be worth trying to get that working
first.
I don't know but I'm assuming it can. I'm progressing on that basis anyway.
OK, I assume the Widget is spinning, etc.
Yes, it is.
I will take a look at the schematics for the I/O board
and the Widget. I
wonder if it's posssible to easily see if the machine is even trying to
access the drive.
Right. This is a Sony 400K drive, as in the other
Lisa, right? To
eliminate the silly faults, I would at least check the power at the drive
connector, and also see what the various signals are doing.
Good idea.
On the other hand it may mean the system is not
looking for either of
them for some reason, and therefore doesn;t notice they are not connected.
True.
A few very quick checks (I hope).
1) Check the power supplies at the floppy drive.
Unlikely to be the
problem, but let's eliminate it.
Yes, I'll check this.
2) Check the logic signals the floppy drive interface
connector. Is there
any activity (changing signals) here? Anything chenge when you put a disk
in?
Nope the drive is dead. And this time even with DD disks! Lights are on
inside it though so it might be getting power. The drive's been
cleaned/relubed and the platter turns. It would be worth me checking out
the signals on the card edge though and comparing them to the working
machine.
4) The floppy coitnroller has its own 6504
microprocessor I believe. Can
you see activity (changing signals) on the address and data bus of this
processor?
I swapped out with a known good one, and it didn't make any difference.
I appreciate these comments and help Tony. Anyone else, please feel free to
chip in.
Terry