What diskettes will work with 1541 diskette drive for C64?

[karateed]

Hi Folks,

Quick question for those that know. I'm new to the C64 but have been playing for it for a few hours. I'm kind of getting the commands down now for the 1541 diskette drive. I saw in some documentation that the 1541 takes single sided, single density diskettes. Is that absolute or can it take single sided, double density under certain conditions.... what about double sided, double density?

The reason I'm asking is that I don't have any single-sided, single density diskettes so have been trying other diskettes that I have including sd, ds and dd, ds diskettes. I didn't really expect them to work and so far they haven't. What does happen is the drive appears to be trying to format the diskette then after about 4 'normal' head clicks gives a loud bbbrrrrrrr and then stops with the red light flashing. I'm going to assume a flashing red light is bad news.

Anyway, I have a line on a few ss, sd diskettes so when they get here, I guess I'll be able to test it out.

Thanks folks,

Ed.....

[Bish500]

Hi, Ed. The 1541 is pretty versatile. It can use SSDD, DSDD, DSQD (Quad Density).

It sounds like you're getting error 74 (Drive Not Ready).

Once you get the red blinking error light, you can type in this little program, and it will tell you what's wrong. (you have to type it in - if you try to load it in from a disk, you'll clear the drive's error channel, and then you will get 0,OK,0,0)

10 open 15,8,15
20 input# 15,a,b$,c,d
30 print "error number: ";a
40 print "error name: ";b$
50 print "on track: ";c
60 print "sector: ";d
70 close 15

I'm guessing (and this is only a guess!) the problem is that the media you're using had dropped some oxide on your read/write head of your floppy drive, making it too "dirty" to work with disks.

Floppy disks are between 25-35 years old now, and the coating on them starts to degrade and separate from the surface of the disk. When it flakes off and lands on your magnetic read/write head, it coats it, and stops it from reading/writing other media.

You can clean it one of two ways...you can use a cleaning disk, with a little bit of isopropyl alcohol on it (these disks are usually white inside - which you'd see in the little oval window on the disk - this is likely very hard to find now), or you can take the cover off your drive, take a cotton swab and some isopropyl alcohol and clean it manually.

The next trick is to figure out which disk dirtied your drive, and get rid of it.

You might also get this error, if there was a "write protect sticker" over the notch on the upper right side of the disk, if the read/write head was physically stuck, if the drive door isn't closed, etc).

Error 74 (Drive not ready), just really means there was an issue accessing the disk.

I hope this helps.

[Zippy Zapp]

Welcome. As stated above 2SDD, 1SDD but not DSHD disks. If they say HD then stay clear. Quad Density disks are actually 1SDD or 2SDD but certified to 96tpi. You might see these as 3M brand RX50 disks or similar.

Also I have found many, many (as in cases) of 3M 1SDD disks that have failed with spots on the surface even from sealed containers. So I avoid that brand now. Sony, BASF, Verbatim, Dysan, Elephant, Maxell are all good quality and have held up to time pretty good.

[KC9UDX]

HD disks generally do work, I've never had problems with them, but in theory they shouldn't work well. So do avoid them for now.

Do follow Bish500 advice about retreiving the error message from the drive. If you don't want to do so much typing though, do what I do, which is this:

1oP1,8,15:iN1,a$,b$,c$,d$:clO1:?a$,b$,c$,d$
rU

Possibly you have a dirty R/W head. It could also be that the drive hub is not gripping the disk cookie. But try cleaning the head first.

[karateed]

Hi Folks,

Here's what I've done so far - btw, the symptoms are on this video - https://youtu.be/ZTaHgnSZGqs

1 - Cleaned the head, it wasn't that dirty at all, I've seen much worse that actually still worked.
2 - Changed out 3 chips, UC2 - UC3 -UC4 starting with UC3 then UC2 and finally UC4, the 6502. I did this one at a time and checked after each swap. These are known good chips that I've put in.
3 - Move the drive head forward to check it would travel the whole distance needed. It did.
4 - Finally ran the program you gave me and got this - 20, Read Error, 18, 0

I'm thinking I have a hardware issue somewhere here but it will require more than a cursory look at the drive.

Thanks for your inputs so far.

Ed......

[ClassicHasClass]

Or get a fastloader cartridge with a DOS wedge. Epyx FastLoad cartridges are cheap and good enough.

[KC9UDX]

Or get a fastloader cartridge with a DOS wedge. Epyx FastLoad cartridges are cheap and good enough.

I'm finally getting ready to give up on those and switch to JiffyDOS. I had heard in the past that it would cause IEC printers to stop working, but the documentation clearly states that is not the case. The only thing which won't work is the K7 interface, and I guess the only way I can deal with that is to switch back to the stock KERNAL ROM when I need to work with K7s. Or, just do all my K7 work on the PET or VIC-20.

If I had known that JiffyDOS wouldn't interfere with stock operation of non-JiffyDOS disk drives and printers, I probably would have switched to it decades ago.

In the future, the only trouble I'll have is that I plan to make my own KERNAL replacement. I know how the stock seriall stuff all works, and can write replacement routines for that, or in the worst case copy the existing ones from the stock KERNAL. I don't know how JiffyDOS works, and I suspect I would have to reverse engineer it if I wanted to write my own code, or buy a JiffyDOS licence for each of my KERNAL chips I make, and copy the parts of that ROM that I would need. That is not a very appealing solution. Alternately, I would ditch the IEC altogether and either add parallel GPIB, or do something totatlly different, which is what I had originally planned, anyway.

[Scali]

Double-sided disks work fine. They're the same as single-sided disks, except the magnetic coating is applied to both sides.
For the 1541 that doesn't matter, since it only has one head, so it never 'sees' the other side.
DSDD floppies are probably the most common, and will work fine.

You'll also want a 'punch' like this one:



Basically it cuts a write-protect hole into the left side of the sleeve, as opposed to the right side.
What this means is that you can insert the disk upside-down, and use the other side as well.
Of course you'll want double-sided disks for that.
This was common practice, various games and demos will use two sides of the disk and have a 'flip disk' screen.

[KC9UDX]

Almost. Common practice was a round hold punch or a pocket knife.

[karateed]

Or a pair of scissors, that's what I used to do.

Ed......