@Tattooed_Mummy we are trying to replace humans with humanlike computer programs. What could possibly go wrong? Calling it now: we will soon have equivalents of babysitters, teachers and psychologists for AIs. Assuming that next steps will be memory and self correction in AI development.
@nikatjef@tob@Tattooed_Mummy My point. And memory is already on its way and will be another game changer for current models. I do think that AI will still do great strides, but I don't see the point or better: I see a lot of drawbacks and dangers. We totally lose track that whatever we do we should do it for humanity, not "because".
And these are the before and after pictures of the cast metal frame. I used deoxit and an old cloth and cotton buds to remove the dirt and cover the metal at the same time with the deoxit, which usually gives a very thin coating that will protect the metal. Smells horribly though. :) I think I will need to lube the top and bottom ball bearings of the spindle. The top one I can reach easily. For the bottom one I probably have to unmount the flywheel, but I don't want to...
The read/write head is freshly cleaned, the rails have their dust removed and a thin coat of lithium grease has been applied to all surfaces that slide around.
Now everything is put back together. All things that I could reach are lubed. I am slightly optimistic... To do: * one more drive mechanism * testing the transformer * maybe getting rid of the mains filters...?
This is drive unit 0, which I still have to clean. It looks better AND worse at the same time as drive unit 1. The corrosion on the die cast metal looks worse, but the microswitch looks better. The spindle motor looks slightly different...
Interesting! The two mechanisms are slightly different! Drive unit 1 is a 101S and drive unit 0 is a 101SM. I wonder what the differences are, except for the slightly different motor. To me the motors look exactly like the tacho motors used on the Micropolis mechanisms. I do have one or two spares should the need arise...
Another interesting difference compared to the 8050 with Micropolis drives is this weird contraption at the back of unit 0. It is there to support the drive PCB! On Micropolis drives the PCB is simply mounted on top of the mechanism. But the MPI mechanisms only allow for a half length PCB! So the Commodore built PCB hangs over at the end and has to be supported!
And another before and after picture for the metal frame. The white crust leaves behind dark splotches. I wonder if this can be treated in some way to avoid future corrosion? So far I have used deoxit, which lubricates with some kind of synthetic oil, so I hope this will keep corrosion at bay.
The motor of the 101SM mechanism is a slightly different variant. All the motors have tachometers, so they have four wires: two for the actual motors, two for the tacho. For the drive unit this black piece fell of, it was glued to the top, same as visible in this pic for the other motor. I wonder what it's for. First I thought maybe it's a magnet for the tacho, but it seems to be a solid plastic piece, not magnetic.Maybe some kind of protection for the cables?
Now that we know that we have good voltages let’s have a look at the mainboard. The CBM floppy drives are peculiar in that they are multi CPU systems. The 8050 and its relatives have two 6502 CPUs. One, together with some SRAM, ROM, and a 6522 drives the IEE488 bus, also known as GPIB. The other 6502 drives the floppy mechanisms and decodes the GCR data. The ICs have a bit of corrosion on some pins. But luckily all the chips can be replaced if necessary.
There are also two MOS6532A chips, also known as RIOT or RAM IO Timer. The same chip was used in the Atari 2600. Each comes with 128 bytes of RAM. I guess these are used for controlling the floppy drives and act as working memory/buffer for the CPU‘s GCR encoding and decoding. But this is just a guess. I would have to check the schematics…
Next up: all socketed ICs get reseated and the sockets get deoxit applied. The sockets are dual wipe AMP branded. None of that single wipe rubbish Commodore would later use!
After I mounted the mainboard back into the case, and verified that the correct voltages were still on the transformer output, I attached one drive unit and switched the device on. LEDs came on, but drive LED didn't turn off! Okay, that is not good, but we can work with that! Motor spins up when closing the latch -- that is excellent! ...to be continued...
https://www.youtube.com/root42 Coding, tinkering, ancient hardware and software. he/him#retrogaming #letscode #demoscene If you want to support me, you can do so at the links below. I also have Ko-Fi, but there aren’t enough entries…