General Stuff(tm)

[stephen_usher]

Found enough energy to go to the storage and retrieve the F2 and FP.

The board works fine in the second slot on the F2. Unlike the F1, if a virtual disk is formatted as 20MB it see it as 20MB... Well, until the format command blindly formats it as 10MB. :-/

Not tried the FP yet.

[stephen_usher]

Bother! The FP seems to have a memory problem yet again.

[stephen_usher]

Swapped the upper half of the lower bank RAM chips with the upper half of the upper bank and the machine is stable again.

This means that one of those 8 Motorola 4256 RAM chips is faulty. However, the RAM tester I have passes all 8 chips. Not really surprising as the fault only appears after a few of minutes of run time and the RAM tester doesn't power the chip for long enough to cause the failure.

But... which chip is it?

[rubber_jonnie]

Swapped the upper half of the lower bank RAM chips with the upper half of the upper bank and the machine is stable again.

This means that one of those 8 Motorola 4256 RAM chips is faulty. However, the RAM tester I have passes all 8 chips. Not really surprising as the fault only appears after a few of minutes of run time and the RAM tester doesn't power the chip for long enough to cause the failure.

But... which chip is it?

You could try warming up each chip gently while you test repeatedly, see if one fails over time?

[stephen_usher]

I may try that but my first approach was to try my mem test program...

But that needed to be transferred onto the computer...

First the Gotek wouldn't talk to the FP, something I've used time and time again. Then the internal floppy stopped reading disks.

"Aha!", I thought, "Now that I have the working hard drive card I can put the test files on there via another machine."

Then the F2 refused to read floppies modified by my MacBook Pro, so I transferred the files onto the TT, reformatted the floppy and copied them back. The Apricot seemed happy this time... except the files I copied were corrupted in some way. Oh, and the second drive on the F2 stopped reading floppies at all.

At this point I'm giving up for the day. Nothing is going right and my cold has completely sapped my energy. Time for some vegging on the sofa.

P.S. The only reliable machine I seem to have at the moment is my trusty TT. :-)

[JezC]

P.S. The only reliable machine I seem to have at the moment is my trusty TT. :-)

Hope that doesn't jinx that one as well! :hide:

Hope you start to feel better soon!
:awwww:

[rubber_jonnie]

I may try that but my first approach was to try my mem test program...

But that needed to be transferred onto the computer...

First the Gotek wouldn't talk to the FP, something I've used time and time again. Then the internal floppy stopped reading disks.

"Aha!", I thought, "Now that I have the working hard drive card I can put the test files on there via another machine."

Then the F2 refused to read floppies modified by my MacBook Pro, so I transferred the files onto the TT, reformatted the floppy and copied them back. The Apricot seemed happy this time... except the files I copied were corrupted in some way. Oh, and the second drive on the F2 stopped reading floppies at all.

At this point I'm giving up for the day. Nothing is going right and my cold has completely sapped my energy. Time for some vegging on the sofa.

P.S. The only reliable machine I seem to have at the moment is my trusty TT. :-)

Ahhh, I hate days like that!!

[stephen_usher]

Thanks @JezC :-)

@rubber_jonnie Yeah. I did get a little more energy this afternoon and that obviously was enough to coax the FP's floppy drive into working.

I still have to do transfers in a two stage process:

• Mac + USB floppy drive -> 720K floppy -> TT (I could use a 1.44MB disk as the TT has a high density drive and Ajax chip fitted.)
• TT -> Atari formatted 720K floppy -> Apricot FP.

If I even read the floppy on the Mac then the Apricot can't read it. I think it's 'cos of all the hidden cruft MacOS writes to the disk just to index it for itself and that's possibly being written by the USB floppy in a way old controllers can't handle.

[stephen_usher]

Oh, one thing I've discovered about the FP... I've upgraded the internal memory to the full 1MB that there is space for and changed a jumper.

The system when booting reports something like 896K.

If I write to anywhere above 640K though the system crashes.

The Portable and FP were never sold with 1MB fitted and there was never an option to internally upgrade them. I wonder if there's flaw in the design which means that the upper 512K never worked properly. I wouldn't be surprised as having more memory available than an IBM PC/XT may have been able to be a selling point.

It's not an OS issue as the F1/2/10 with a RAM expansion can go up to 768K usable.

[stephen_usher]

Bother! The cold I thought I had was actually COVID-19. I only found out when I took a test to prepare to go back to work tomorrow.