apple Lisa2. One working!! - one to go?

Terry Stewart terry at webweavers.co.nz
Thu Dec 9 16:58:32 CST 2010


> 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 





More information about the cctech mailing list