XF551 compatibility question

[Fox-1 / mnx]

Probably a dumb question, but can't you just glue a small magnet to the spindle motor and detect the rotations with a hall effect sensor,

 

No, it's not a dumb question. It just works, as proven by several people.

[Mathy]

Hello guys

 

I'ld be very careful when it comes to magnets and floppy disks.

 

CU

 

Mathy

[kurtm]

Hello guys

 

I'ld be very careful when it comes to magnets and floppy disks.

 

CU

 

Mathy

 

Glad it wasn't just me who thought that first

 

--Kurt

[31336haxx0r]

I'd be careful, too. But then... this may explain, why 3.5" disks fail ALL the time.

[Fox-1 / mnx]

The magnets "we" are talking about are ridiculous small and located relative far away from the media so no harm done. One could exchange this with a LED (preferably infrared) and optical receiver combo to get the same effect.

[+Larry]

FWIW... I have several XF551 drives and all have or had Mitsumi mechs. Good drives; very quiet. But unless you put in a 720K mechanism, it's really not much better than a 1050, except slower (if you have a 1050 Super Archiver or Happy or USDoubler). It has one dubious advantage -- 360K DS/DD. I personally never got very excited about that format. 720K is much nicer, and with 3-1/2" 720K disks, more reliable. And wow, that gray plastic yellows! XF PCB's are bad karma. If you get one, make sure that you reinforce the SIO jacks with machine screws/nuts. In fact that is a good practice for 1050's, too.

 

-Larry

[BillC]

I'd be careful, too. But then... this may explain, why 3.5" disks fail ALL the time.

Most 3.5" floppy drives do not have a belt drive motor, the motor is directly attached to the spindle. I doubt very much that the weak magnet/sensor the other side of this motor from the disk would be the cause of the failure.

 

The magnets "we" are talking about are ridiculous small and located relative far away from the media so no harm done. One could exchange this with a LED (preferably infrared) and optical receiver combo to get the same effect.

An optical receiver combo is exactly what the original index sensor is, but it is difficult to locate either transmitter or receiver on the rotating spindle due to the wiring required which is the reason neither of them was placed there in the first place.

[Fox-1 / mnx]

An optical receiver combo is exactly what the original index sensor is, but it is difficult to locate either transmitter or receiver on the rotating spindle due to the wiring required which is the reason neither of them was placed there in the first place.

 

It isn't difficult to place it at all.

 

LED and receiver are both mounted next to the side of the spindle, each in an 45 degree angle. The side of the spindle has to be painted black except for one small gap which is the place the LED will reflect it's light which will be seen by the receiver. If the reflection is too weak, just put some reflective/silver tape on the spindle.

[Fox-1 / mnx]

But unless you put in a 720K mechanism, it's really not much better than a 1050, except slower (if you have a 1050 Super Archiver or Happy or USDoubler).

 

You can't compare a stock drive with a modded one. A stock XF551 is faster than a stock 1050. If you want to compare it with a 1050 USD, put it next to an XF551 modded with a Speedy-XF.

 

It has one dubious advantage -- 360K DS/DD. I personally never got very excited about that format. 720K is much nicer, and with 3-1/2" 720K disks, more reliable.

 

The 360K DS/DD is a BIG advantage as it uses plain PC-/ST-like mechanics. And since when are 3,5" disks more reliable? I had piles of failing 3,5" disks where my much older and misused 5,25" disks keep on going.

 

And wow, that gray plastic yellows! XF PCB's are bad karma. If you get one, make sure that you reinforce the SIO jacks with machine screws/nuts. In fact that is a good practice for 1050's, too.

 

The yellowing may be a problem for some people but it doesn't do any harm to the functionality but my XF's are still more grey than my XE's are. It's true the quality of the PCB is not very high but I've never got any problems (yet?) with the SIO connectors, even the ones that are plugged in/out many many times.

[+Larry]

Hi Fox-1-

 

We're going to agree to disagree here...

 

You can't compare a stock drive with a modded one. A stock XF551 is faster than a stock 1050. If you want to compare it with a 1050 USD, put it next to an XF551 modded with a Speedy-XF.

 

Sure I can. If I already have a modded 1050 and I'm considering buying an XF551 as an "upgrade," its a very logical comparison. I have both stock and modded XF's, and a CSS or Hyper-XF with a 720K mech is a very nice drive. It's true that a stock XF in DS/DD is faster than a stock 1050 in DD.

 

The 360K DS/DD is a BIG advantage as it uses plain PC-/ST-like mechanics. And since when are 3,5" disks more reliable? I had piles of failing 3,5" disks where my much older and misused 5,25" disks keep on going.

 

True, the 360K "industry-standard" mechanism is nice. More reliable, since it was designed many years after the Tandon 1050-type mechs. But it's the DS/DD format that IMO is not very handy. The lowest common denominator for the Atari is 90K and after that is SS/DD 180K, and probably ED after that (at least here in the US.) Thousands and thousands of them "out there." If it's storage that you want, then why not put in a 3-1/2" mech. The issues already raised about back-side formatting and writing make the stock XF less-than-handy, too (IMO). BTW, will a Speedy format and write to the back side of the disk? (I suspect that it still depends on the type of mech, but it's not a rhetorical question.)

 

Your experience with disks must be radically different than mine; I've had essentially zero issues with *true* 720K, 3-1/2" disks on my Atari (or in past years, the PC or ST). 1.44's -- very different story, especially if written as 1.44's. You aren't comparing 1.44's used on a PC with 720's used on an Atari, are you? ("...piles of failing 3,5" disks" -- piles of failing 3-1/2" Atari 720K disks???)

 

The yellowing may be a problem for some people but it doesn't do any harm to the functionality but my XF's are still more grey than my XE's are. It's true the quality of the PCB is not very high but I've never got any problems (yet?) with the SIO connectors, even the ones that are plugged in/out many many times.

 

I've had maybe 10 XF's and two of those have had broken traces at the SIO jacks. It's true that is just my experience, but the mode of failure is common, and reinforcing the jacks is simple and prudent.

 

In summary, I'm not saying that the XF is a "bad drive." I am saying that it has some issues, and much of this can be "cured" by making the drive into a 720K via the Bob Woolley mod or CSS or Hyper-XF mods. I guess I'm also saying that if I wanted to buy an XF as an "upgrade" to a modded 1050, I'd only consider it an upgrade if I put in a 720K mech.

 

-Larry

[flashjazzcat]

Unfortunately by putting in a 720K mechanism, you no longer have a drive that will read your 5.25" disks. All well and good if you have another drive or a dual 3.5" / 5.25" mechanism. On balance I find the DS/DD format of a stock XF a nice compromise which maintains backward compatibility. At the end of the day, a stock 1050 is a 130KB drive, and a stock XF has almost three times the storage capacity.

[+bf2k+]

It's true that a stock XF in DS/DD is faster than a stock 1050 in DD.

 

 

A stock 1050 doesn't do DD. Stock 1050's only do 128 bytes per sector.

 

I've had maybe 10 XF's and two of those have had broken traces at the SIO jacks. It's true that is just my experience, but the mode of failure is common, and reinforcing the jacks is simple and prudent.

 

I fixed one of my XF's with the same problem. I've also had 2 ON/OFF switches fail on XF's.

[+Larry]

> A stock 1050 doesn't do DD. Stock 1050's only do 128 bytes per sector. <

 

Yes, my bad. I should have said a modded 1050 at 1X SIO. But my point was that the SIO capability of the XF in DS/DD is faster with the appropriate drivers. But of course, slower than Ultra Speed mods.

 

To me the end of the day is this: if I already have a modded 1050 (the original premise of this thread), will I be better off by also purchasing a stock XF551? Clearly there is no one "right answer," but I'd say that my 720K point of view is valid. Of course, now I use APE and images 99% of the time, but that's a whole different issue.

 

-Larry

[flashjazzcat]

You'll be better off in the sense that you'll have two cool retro Atari disk drives instead of one. I rest my case.

[Fox-1 / mnx]

We're going to agree to disagree here...

 

You're welcome :-)

 

You can't compare a stock drive with a modded one. A stock XF551 is faster than a stock 1050. If you want to compare it with a 1050 USD, put it next to an XF551 modded with a Speedy-XF.

 

Sure I can. If I already have a modded 1050 and I'm considering buying an XF551 as an "upgrade," its a very logical comparison.

 

I still think it's not a fair comparison. If you consider to buy a _modded_ XF551 as an upgrade, it would be fair.

 

True, the 360K "industry-standard" mechanism is nice. More reliable, since it was designed many years after the Tandon 1050-type mechs. But it's the DS/DD format that IMO is not very handy. The lowest common denominator for the Atari is 90K and after that is SS/DD 180K, and probably ED after that (at least here in the US.)

 

All the formats you mentioned are supported by the XF551. The 360K is a bonus. The mechanic is not only more reliable but also more common so easier to replace in the case it breaks down.

 

If it's storage that you want, then why not put in a 3-1/2" mech.

 

Because I put in a Cumana 360/720KB 5,25" mechanic in one of mine. With the flip of a switch it turns the 40 tracks XF551 into an 80 tracks 720KB disk drive.

 

The issues already raised about back-side formatting and writing make the stock XF less-than-handy, too (IMO).

 

That's true but can easily be solved. Much easier than putting a Happy upgrade into a 1050.

 

BTW, will a Speedy format and write to the back side of the disk?

 

Yes it does. (I don't have one b.t.w.)

 

You aren't comparing 1.44's used on a PC with 720's used on an Atari, are you? ("...piles of failing 3,5" disks" -- piles of failing 3-1/2" Atari 720K disks???)

 

I actually meant 3,5" disks in general and however most are 1,44MB disks there are more than enough 720 ones with the same problem. Way more than I ever had bad 5,25" disks.

 

 

I've had maybe 10 XF's and two of those have had broken traces at the SIO jacks. It's true that is just my experience, but the mode of failure is common, and reinforcing the jacks is simple and prudent.

 

With you included, I now know about 4 people who actually USE(d) XF551's who say the SIO jacks are a common problem. All other people from who I read this never even owned one :-)

 

I can only say I never had the problem and I have some really misused disk drives (up to cracked cases and parts of the mechanic coming loose due to 1000's of kilometers bouncing in the trunk of the car).

 

In summary, I'm not saying that the XF is a "bad drive." I am saying that it has some issues, and much of this can be "cured" by making the drive into a 720K via the Bob Woolley mod or CSS or Hyper-XF mods. I guess I'm also saying that if I wanted to buy an XF as an "upgrade" to a modded 1050, I'd only consider it an upgrade if I put in a 720K mech.

 

The 1050 isn't a bad drive either. I used those even more than my XF551's, mostly because they are faster and have a built-in DOS. Nowadays I don't use disk drives that often as most of my stuff is on hard disks but I still have an XF551 360/720 5,25" and XF551 360 5,25" / 720 3,5" at hand for the floppies I have laying around that were written on those drives.

 

I have the feeling the XF551 is getting a bit of a bad reputation only because of some people who re-post the experiences of others (not necessarily on AtariAge b.t.w.).

 

I see it like this: Both You and MetalGuy wrote something about bad SIO jacks. For each of your posts there are at least 10 people who read it and use the info to write somewhere on another forum/blog a thing like: The XF551 SIO jacks suck. Withing 2 weeks there are 22 message's about XF551's with bad SIO jacks on the net, however only 2 of them actually know about how and what. And after that come the people who read those forums and blogs again and think they need to write something about it too :-)

 

This is of course just an example but I guess you get the point :-)

[Shawn Jefferson]

My XF551 had bad SIO jacks too, had to resolder them to get it to work.

[Fox-1 / mnx]

Maybe the quality of my XF's is different as these were the very last ones Atari made? Don't know.

[Mathy]

Hello Robert

 

I own two XF551's. One works fine, the other has bad SIO jacks.

 

CU

 

Mathy

[31336haxx0r]

I have two XFs and both are fine. What can I do to keep them that way?

[flashjazzcat]

Mine was thrashed from 1989 to 2000 and still works today. SIO plug was inserted and removed dozens of times, and I've done nothing more than grease the head rails a couple of times as a precaution. Still giving service today after nearly a decade in storage.

[+bob1200xl]

The XF551 has a very poor motherboard, more like ones found in toys and very cheap electronic products. Because of this, you must be careful with how you handle them, particularly at the SIO ports. If you twist the cable too hard while removing it, you may break the solder joint at the SIO connector. Different SIO cables require different amounts of torque - be careful. Some of the XF551s have flimsy rivets holding the SIO to the PCB - use nuts/screws if possible.

 

Other than that, there is not much that you need to do.

 

Bob

 

 

 

 

I have two XFs and both are fine. What can I do to keep them that way?

[31336haxx0r]

Thanks!

[ijor]

I admit I never liked the XF551, but I can understand there is a strong matter of personal preferences and usage here.

 

The "PC standard" mechanism is a mixed blessing. It has some benefits, but is also brings to the XF551 an incompatibility issue that it is almost unsolvable. It is the different rotation speed. Many people would not care, I guess, this affects only some copy protected disks.

[Fox-1 / mnx]

but is also brings to the XF551 an incompatibility issue that it is almost unsolvable. It is the different rotation speed.

 

Sure it's solvable.

 

The "XFD602" is a (more or less) similar drive, also using these 300RPM PC style mechanics, but at a steady 288 RPM.

 

The German "Floppy 2000" uses a trick to compensate for the 300RPM but I forgot what it was.

[ijor]

Sure it's solvable.

 

Everything is solvable. The question is how easy or complicated it is. How easy is for a regular XF-551 user to solve this?

 

The "XFD602" is a (more or less) similar drive, also using these 300RPM PC style mechanics, but at a steady 288 RPM.

 

That's quite a different scenario. One thing is to manufacture a disk drive rotating at 288 RPM. The manufacturer could find specific PC mechanisms that are not so difficult to modify (back at the day, you could probably even get help from the original mechanism's manufacturer). Another thing is for the user to modify the RPM speed of just a random PC mechanism.

 

The German "Floppy 2000" uses a trick to compensate for the 300RPM but I forgot what it was.

 

Well, with today tech you could easily buffer the entire disk and simulate whatever rotational speed you want, but this could be complicated to implement for copy protected disks. Otherwise, without this level of trickey, I don't see how you could compensate reliably without breaking compatibility.