Commodore 1570 and 1571 disk drive repairs - open heads and bad ICs

For me this is very nostalgic. I cam remember back when each of these devices first came out. Reading reviews in magazines, seeing them in ads, and seeing them in person in a variety of stores.
It was also the time I was also transitioning to PC's and not wanting to sink anymore $$$ into my Commodore gear. Now that PC gear is pretty much worthless and these devices at least have some value!

Instead of typing the whole load"$",9 rigamarole, just type c-shift-A (short for catalog) and it'll give you a directory listing without overwriting your BASIC program. In your case, "c-shift-A U9". U8,U8,U10 are your drive numbers. This is one of the DOS wedge commands included in BASIC 7 along with CSAVE, CLOAD, et al.

You may want to store the 1571 with the lever in the closed position (with disk or transport protection inserted), this way the spring of the head assembly will not get bend over time.
the 157x also uses an WD1771 chip to read/write MFM disks.

Just picked up vic 20 myself yesterday. The vic 20 works great, but the drive does have some issues. It was a good deal so it was worth the chance. The 1541 tries to read, and spin but fails to even find a directory. So I hope I can solve the problem. I do have another 1541 drive that works just fine with the vic so at least I know it's not the vic 20. The vic 20 was on of my last pc's on my list that I wanted to own.

I am looking to buy a 1571. Is there any way to tell, from the outside, which mechanism it has?

The grid voltage in Europe is actually 230 volts since 1987! Before than it was 220 volts at least in Germany.

Great work bud. I've said before, you are very smart. I've learned alot from you. Agreed. Alps drives only. Relating to 1541s are you going to retrobright that 128? I know it's hit and miss. Sun method too quick. I recently retrobrighting cases inside. Different method, but successful so far. Slow

I didn't know the R/W heads used AWG 40. That would actually make someone like a guitar technician (or more precisely, a pickup winder) possibly capable of repairing or fabricating new drive heads, as most pickups are wound using even thinner wires (AWG 42 or 43 are most common). Granted, pickups are physically much larger, but the technique should be similar and with some speccing (expected inductance, resistance, turns per layer and layer count) it sounds at least theoretically feasible.

Lovely stuff! I've a bunch of 1541's to repair here and it's something I've never even used before let alone repaired! Picked up a few handy nuggets here.

Police knocked on my door and charged me with willful display of incorrect aspect ratio. My case comes up in 6 months. Writing this from my cell where I'm being held on remand. I can tell you that smuggling in a smart phone is not as much fun as it used to be!

Can you clear up a 38 year 1570 mystery for me? My first computer was a flat c128 with a 1570. The issue was that the 1570 did not support the BasicV7 disk commands (dload, dsave, directory etc) but the V2 commands (load”$”,8 etc) worked. It was returned to the shop and they couldn’t figure it out so I got a replacement 1571.

Can you test the 1570 with a flat C128 and see if the V7 commands work or did I just get a dud drive. Thanks.

Why didn't you replace the SID chips in those drives?

Nice work. I unfortunately have a small pile of open drive head units on the floor of the shed. Good for Logic board parts but not much else. You were lucky????? to only have one go open. Most of the time both are.

I would expect you might be able to change the internal drive number on the 128D with the old 'OPEN 15,8,15:PRINT#15,"M-W";CHR$(119);CHR$(0);CHR$(2);CHR$(device number+32)+CHR$(device number+64):CLOSE 15' commands, then turn on the external drives and test them as drive 8.

Does anyone know if you can get a replacement fuse mechanism for the 1570 ? I have 2 at home & both are missing the fuses & enclosure.

There’s one of these drives for sale at my local tip shop. I bargained them down to $50 but ultimately didn’t buy it as it had no power supply and looked pretty dirty. Plus I don’t have any 64/128 to use it with.

For the 1541, I'm making a SD card solution that plugs into the CPLD/GateArray Commodore custom IC socket and intercepts the head signals just after they become digital. This enables you to use the drive to read disk images or, if the head is still good, as a regular drive. It can be controlled via wifi and a web page accessed via a phone, tablet, PC etc. The CPLD in a 1571 is configured a little different but I may be able to adapt my design. I will have to look into it. From your 1570/1 drives it looks like most of the ICs are not socketed? However, I believe/hope that most 1541s have socketed ICs.

Great Video again! -Mark.

You can make the 1571 with the broken lower head into an Australian 1570 if you plug the spindle motor in backwards! Now wait if you flip the head plugs and remember to put the disks in upside down this might actually work! Except for the write protect notch being on the wrong side.
EDIT: IF this works, also install the badge on the front upside down!

At zimmers there is a copy of the 1570 demo disk.

About the 1571 with not working lower head, I think you could swap the lower head (which is essential to access track 18) with the upper one and turn it into a working 1570 single sided drive, by changing the ROM (or programming a new EPROM)... Good job!!

If it's a Neutronics mechanism, it's unrepairable. But ALPS is good!

You can also use PC mechanics as an alternative in the 1571, such as the newtronics F502 or D503, I have already installed 3, and 2 1571 heads I could already fix the wires, the problem is to remove the epoxy resin, this works with acetone, a strong USB zoom camera is mandatory.

Back in my Commodore 64 days, a 1541 drive would cost you a small fortune. Awesome video, Mark. Thank you!

We have Helmuts all over the place in Germany! 😜

An Helmut lives in my village. About 1km away from here. We had beer together, already 👍🏻

First 🙂