View Full Version : Commodore 64 Disc Drive - will it work on a VIC-20?

November 30th, 2003, 12:25 PM
Whilst getting my VIC-20 out from my loft space, I found a Commodore 64 5.25" Disc Drive I had forgotten I had! It was given to me by a friend about 8 years ago after his C64 broke.

The question is... will this work on a VIC-20? Curiously, the label showing the model number on the back of the drive says "VIC1541". Anyone know?



vic user
November 30th, 2003, 01:14 PM

You should have no problem using the 1541 disk drive with your vic 20, assuming all the parts are in working order.

I use 1541, 1541 II, and 1571 disk drives on my two vic 20's and I have no problems.

I love having two floppy drives hooked up to one vic at a time.

Enjoy your floppy drive!


I have the 1541 test / diagnostics disk. If you need a copy I am sure we can figure out how to get a copy over to you in the mail.

vic user
November 30th, 2003, 01:19 PM
Oh, I was just looking at your pictures of your 1541 disk drive, and it looks like you are missing the lever to raise / lower the read/write head of the drive.

I will look at the picture again, but my first thought is that you will have to use the drive with the lid off. Good for heat loss I guess :)

I hope I am wrong.

Kaptain Skitzo
November 30th, 2003, 05:29 PM
Nah, the lock/ejector-clip is still there. I saw it protruding a little bit. Nice looking drive! Something you might want to do, is give it a good cleaning before ya start using it. Just remover the outter case(4 screws on bottom) and remove the top PCBoard, flip up the little lever you will see above the drive heads, and use a Q-Tip and rubbing alcohol to clean the heads. Also blow out any dust you find inside.

December 3rd, 2003, 05:50 AM

that's great news!!! A Vic20 with the disc drive sounds so advanced, if only I knew this when I used the machine :lol:

power cable is no problem, but I do not have the cable that uses to attach it to the computer, which kind do I need? there are two sockets in the drive.

Do I need any special software to use this drive?

I can't recall anything about the clip at the front of the drive, but I can check again.

I'm looking on eBay for a working vic 20 so I hope to get everything going at christmas 8) 8)

thanks guys :)

vic user
December 3rd, 2003, 06:47 AM

You need a Commodore serial cable, which has two male 6 pin DIN's at each end (I think).

You need no special software to use the serial cable.

It connects to the right most DIN socket on your vic 20 (if you were looking at the back of the vic 20), right near the tape cassette port.

The other socket is the video/audio port.

You can also daisy chain devices to the serial port, so you can have say 2 floppy drives and a printer all linked back to that one serial port on your vic 20. (which is what I am fortunate enough to be able to do)

The computer will know what device to send / receive, based on you using the proper device numbers (e.g. device #8 for floppy #1, device #9 for floppy #2, device #4 for the printer, etc.)

Here is a link I found, if you want to try and make your own serial cable:


vic user
December 3rd, 2003, 09:30 AM
Oh, another thing since I did not read your posting carefully.

One socket on the drive is used to hook up to the computer (the left one when looking at the back of the drive), and the other socket is for the daisy chaining to other devices.

although this may be obvious to you, here is an example:

on one of my vic 20's, i have a 1541 drive connected from the left socket to my vic 20, then another serial cable from the right socket to the left socket of a 1541 II drive (with the DIP switches set to device #9), and then another serial cable from the right socket of the 1541 II to my printer.


December 3rd, 2003, 09:45 AM
oh I see, so the second socket is used for "stacking" or linking more drives? So:

Vic <-- Drive1 <-- Drive2 <-- Printer <-- etc?

Thanks for the site, i will look into making a cable if I can't find one in my parts box !

Is there any website which details using the drive, eg, format/load/save/etc? And the Dip switches - are they in the drive itself?

Thanks for the help (and for putting up with my silly questions!), you've all been really helpful :D

December 3rd, 2003, 09:50 AM
ahh yes, I've found it in the owner's manual :) It doesn't tell you how to use the drive though, just cassette.

A printer would be cool, I'll have a look and see if I have any that look like they could work with it!

vic user
December 3rd, 2003, 10:20 AM
Well I don't think you ask silly questions!

I will poke around and see if I can find an online version of the disk manual somewhere.

If not, I can bring in my 1541 II manual to work, and scan it and then leave it on my yahoogroups I use to store vic 20 files.

The 1541 II manual will work just fine with the 1541, as long as you use the BASIC 2.0 commands.

You sure would like to have the commands that's for sure, as they will give you the proper syntax for things like formatting a drive etc.

One easy thing right off the bat, is that load, save, and verify act just like they do on a floppy drive as they do with the cassette drive. All you need to do is ensure that you use the device number associated with the drive.

for example, when you go to load a program from tape cassette, you normally just type:

and the vic 20 automatically defaults to device #1, which is the casette drive.

to instruct the vic 20 to use the floppy drive you would type:
LOAD "",8 (for device #8 if the DIP switches are set to 8).
Stock 1541 drives are already set to device #8.

to access the floppies directory you would type:
LOAD "$",8 and then when you have the command prompt back, just type: LIST
and you will get a listing of the files on the floppy.

The 1541 DIP switches are inside the case.
The 1541 II DIP switches are outside the case (smart move!)

I just did a quick poke around in a second browser, and i found this link:

lots of manuals!

it has the 1541 manual there, also at the bottom of the page, you will see files for 1541 disk tricks, and another file for changin the DIP switches on a 1541!

If you need a copy of the 1541 test / diagnostics disk, I can send you one via mail.

I hope you have fun!

vic user
December 3rd, 2003, 10:27 AM
I just downloaded, unzipped, and then uploaded the text file for the 1541 disk drive manual, to my yahoogroups thing.

here is the link:


December 4th, 2003, 10:45 AM
The 1541 II manual will work just fine with the 1541, as long as you use the BASIC 2.0 commands.

Actually, the 1541-II was supposed to be an identical replacement to the older model. Some of the ROM bugs were fixed, the power supply was made external (so less risk of overheating) and DIP switches to change unit number are external so you don't have to open the drive and cut some wires on the motherboard to do that. :)

This means as long as you don't use software which takes advantage of the bugs, it should work exactly like the old model. I'd say more than 95% of the software is compatible, if not more.

Btw, the two DIN jacks on the back in many cases are interchangeable, although you might find in certain circumstances a difference how things co-operate based on how their are connected together. One DIN jack is called "SERIAL" and the other is "INTERFACE" IIRC.

December 10th, 2003, 12:28 PM
thanks for that, a really great help there, especially the manual :)

I'll keep this info, and let you know how I succeed when I get it all working with a fixed/replacement VIC!

Thomas Hillebrandt
December 11th, 2003, 12:48 PM
Just thought I'd jump in with a small detail I didn't see the others mentioning.

Now - I've never tried not doing this, so it may mean nothing. However, in my manual for the 1541, I read that you need to slow down the drive to make it work properly with the VIC - and consequently speed it up again for use with the C64.

To slow it, you'd write this command sequence:

OPEN 15,8,15,"UI-"

And to speed it up again, you'd write:

OPEN 15,8,15,"UI+"

...This only needs to be done once, every time you change computers for the drive.

Now, like I said, this may not be necessary (anybody?), but I just thought I'd come with some input in the matter :P

vic user
December 11th, 2003, 03:25 PM
I never knew about that.
I think I will give them a try and see what happens.

I have swapped 1541's, 1541 II's, and 1571's from my vic's to my 64's and back again, and I have never used those procedures, and I have encountered no problems.


December 13th, 2003, 01:05 PM
Nope. You don't have to issue any commands to use the drive with the VIC-20.

Actually it is the other way around; the UI+ and UI- commands are meant to speed up the drive by 15-25% for use with the VIC-20, which has a less complicated timing than the C64 has. This comes from the 1540, a predecessor to the 1541, which was designed for the VIC-20 and thus operated faster. The 1540 might not work with a C64 without blanking the screen.

So, either you use the 1541 in default mode or you issue a command to enter the 25% faster 1540 mode. Both will work fine with the VIC-20.

Thomas Hillebrandt
December 13th, 2003, 01:09 PM
Well, like I said - I've never tried not doing it, so I couldn't vouch for the necessity of it.

I seem to remember that it was speeding up for the C64, though - although I am aware of the serial-port screw-up that Commodore made (bloody imbeciles! :evil: )...I have to say, though, that if UI+ shouldn't work with a C64, then MY C64 must be magic :wink:

December 14th, 2003, 12:25 PM
Ok. From the 1541-II manual:

UI+ restore 1541 to usual speed
UI- speed 1541 up by 25% when used with VIC 20 only

So, the drive boots in the slower + mode and issuing the UI+ command will do nothing unless it has been told to operate in the faster - mode. However, UI- might work with the C64 if you issue POKE 53265,0 to blank the screen.

I wonder what the consequences had been if Commodore engineers had finished the faster protocol for the C64 - probably its peripherals like 1541 and the new printers had not been backwards compatible. Various hard- and software based disk turbos solved this matter though.

Thomas Hillebrandt
December 14th, 2003, 01:35 PM
Ah...Reverse order...That explains it! Never mind, then... :lol: