XF 551 - Doesn't work

[jvas]

I've just bought an XF551 drive, but id doesn't work. I need your help to find out (if possible) what is wrong with it:

- when I turn it on, the head goes to the initial position

- when I turn the computer on, the disk spins up, but the head doesn't move and after ~10 secs I got a "BOOT ERROR" message.

 

I checked the computer with another drive: OK

I checked the cable with another drive: OK

I checked the disks with another drive: OK

I also cleaned the heads.

 

Four questions:

- What else should I do to find out the source of the problem?

- Is it possible to connect a 5.25" drive of a PC to the electronics of the XF551?

- Does it worth to repair it?

- Who can repair it?

 

Thanks in advance,

Jozsi

Edited June 4, 2007 by jvas

[walter_J64bit]

I've just bought an XF551 drive, but id doesn't work. I need your help to find out (if possible) what is wrong with it:

- when I turn it on, the head goes to the initial position

- when I turn the computer on, the disk spins up, but the head doesn't move and after ~10 secs I got a "BOOT ERROR" message.

 

I checked the computer with another drive: OK

I checked the cable with another drive: OK

I checked the disks with another drive: OK

I also cleaned the heads.

 

Four questions:

- What else should I do to find out the source of the problem?

- Is it possible to connect a 5.25" drive of a PC to the electronics of the XF551?

- Does it worth to repair it?

- Who can repair it?

 

Thanks in advance,

Jozsi

 

Try www.myatari.com

[+Guitarman]

I've just bought an XF551 drive, but id doesn't work. I need your help to find out (if possible) what is wrong with it:

- when I turn it on, the head goes to the initial position

- when I turn the computer on, the disk spins up, but the head doesn't move and after ~10 secs I got a "BOOT ERROR" message.

 

I checked the computer with another drive: OK

I checked the cable with another drive: OK

I checked the disks with another drive: OK

I also cleaned the heads.

 

Four questions:

- What else should I do to find out the source of the problem?

- Is it possible to connect a 5.25" drive of a PC to the electronics of the XF551?

- Does it worth to repair it?

- Who can repair it?

 

Thanks in advance,

Jozsi

 

 

The XF-551 are notorious for the SIO connectors coming lose from the circuit board. If you are half way decent at soldering, it is an easy fix. Just resolder the SIO connector connections to the board. If any of the traces the connector is attached to seems to be cracked or broke, just attach a small jumper wire over the crack/break. This should hopefully get the drive up and running as this issue accounts for probably 80% of non-working XF-511 drives.

[+Larry]

I've just bought an XF551 drive, but id doesn't work.

(... snip... )

Jozsi

 

The symptoms you describe suggest to me the mech is damaged or mis-aligned. However it also could be a cracked SIO trace on the drive board. You can use a meter (VOM) to check the continuity of the SIO pins/traces. If not repairable, a replacement board will cost you about $75 + shipping. (ouch!)

 

If it is the mechanism, you can replace it, but it should be a low-power PC-type. The least-cost and most available replacement will be a 3-1/2" HD mech. which will operate in the Atari in double-density mode -- provides 720K storage. This is truly an upgrade, and it avoids the potential compatibility issues of having double-sided 5-1/4" disks in your collection. As a bonus, 3-1/2" (720K) disks are generally more reliable than 5-1/4" in double density.

 

There are several 3-1/2" upgrades available including the Hyper-XF upgrade and the original Bob Woolley upgrade. You can research these on the web. You will need a different eprom (rom) for any mod that you would do.

 

If you want to keep this as a 5-1/4" drive, you can check around, but if you don't have any luck, PM me -- I have several good, used 551 mechs.

 

-Larry

[jvas]

...

 

There are several 3-1/2" upgrades available including the Hyper-XF upgrade and the original Bob Woolley upgrade. You can research these on the web. You will need a different eprom (rom) for any mod that you would do.

 

...

 

Am I right, that the "Bob Woolley" upgrade is a simple EPROM replace? Will it work with an 1.44 PC drive? Where can I find the original/modified ROM content? Maybe mine is damaged (that is currently in the XF).

[+Larry]

...

 

There are several 3-1/2" upgrades available including the Hyper-XF upgrade and the original Bob Woolley upgrade. You can research these on the web. You will need a different eprom (rom) for any mod that you would do.

 

...

 

Am I right, that the "Bob Woolley" upgrade is a simple EPROM replace? Will it work with an 1.44 PC drive? Where can I find the original/modified ROM content? Maybe mine is damaged (that is currently in the XF).

 

Yes it is an eprom change (plus the drive mech). Since you are changing from a 5-1/4" mech to a 3-1/2", the connectors are different, and you will have to change the ribbon connector, probably using a short adapter cable which you will probably have to make yourself.

 

Yes, a 1.44 drive should fine work in 720K mode. I did one of these drives about 1990 or so. I guess a caution would be that recent 1.44 drives don't have the drive select (1-4) jumpers on them. That might affect which drive numbers you could use with the Atari. (?) I did this mod back around 1990, and it came out fine for me.

 

If you search the web with "Bob Woolley Atari XF" you will find info. About the rom/eprom, it's all explained in Bob"s article. Bob also wrote a short update later that improved the density sensing, IIRC.

 

Bob Woolley's XF upgrade article was published/uploaded in several places.

Try here: http://www.jorevall.com/freddie/8bit/FILES/XF551P.TXT

 

Two added notes about this. First, the Woolley upgrade operates at about 2X SIO, so it is not quite as fast as a 3X (Doubler-type) drive. Second, if this sounds like too much work, CSS (www.nleaudio.com) may still sell an upgrade kit that probably will make life easier. It has a 3X SIO speed eprom, and is available as a single or dual-drive upgrade.

 

-Larry

[dinosaur]

I hope that the file that I sent you will help.

 

Personally,I find the Xf551 drives are not worth the trouble,especially in the 3.5" mod.

 

The trouble of two disk sizes,and the way that the XF551 writes in the IBM manner,creates

 

complications that I can do without.

 

I like US Doubled 1050 or (my favorite..) Indus GT drives.

 

Using flippies,you have available single density and double density.

 

Makes me happy

[jaybird3rd]

Yes, a 1.44 drive should fine work in 720K mode. I did one of these drives about 1990 or so. I guess a caution would be that recent 1.44 drives don't have the drive select (1-4) jumpers on them. That might affect which drive numbers you could use with the Atari. (?) I did this mod back around 1990, and it came out fine for me.

 

If you search the web with "Bob Woolley Atari XF" you will find info. About the rom/eprom, it's all explained in Bob"s article. Bob also wrote a short update later that improved the density sensing, IIRC.

I can also confirm that a 1.44MB mech will work. I performed this modification within the last year, using a new Sony MPF920 mech that I bought from Newegg. Even though the drive select jumpers have long since been removed from that drive, I was able to find out how to reconfigure it for the '551 by studying the PCB; I probably had to cut a trace and move a resistor or two. I don't remember the particulars, but I did take some pictures of the steps I took, and I'll try to dig them out and post them tonight in case they'd be helpful. I also wired the density switch closed so the drive always remains in DD mode regardless of the type of diskette that is used.

[Mathy]

Hello guys

 

Yes, a 1.44MB drive will work, but only in 720kB mode.

 

If you use a small piece of ribbon cable and the right connectors, you don't have to modify the ribbon cable inside the XF551.

 

And if you swap the right wires on that cable, you can get any drive to react, without cutting traces.

 

Wire number 10 is D0 select, 12 is D1, 14 is D2 and 6 (not 16 as you'll expect) is D3.

 

If you drive mech is set to D1, swap wires 12 and 10.

 

BTW Bob Woolley's upgrade came in two parts. The first one solved the density problem and got you 80 tracks (720kB). What the second one does, I do not know.

 

Greetings

 

Mathy

[jvas]

Thanks everybody for your help. I'll do the "Bob Woolley" upgrade and let you know. I prefer this one, since it is easy to do (I've just brought an eprom burner) and the drive mechanism can be replaced easily. I just examined my 1050 and I can tell you that if the drive goes wrong it must be go to the dustbin. No way to replace it (at least I cannot do)

[jvas]

Funny thing:

The original OS in my XF551 can handle an 3.5" drive. At least I could format it, I could duplicate DOS 2.5 to it and I could boot from it. Can anybody explain this?

[+Larry]

Funny thing:

The original OS in my XF551 can handle an 3.5" drive. At least I could format it, I could duplicate DOS 2.5 to it and I could boot from it. Can anybody explain this?

 

Have you tried to fill the 3.5" disk beyond 40 tracks? It should not work. But up to 40 tracks -- should be same as the old 5-1/4".

Evidently your 551 board was OK, if you swapped the mech and it formatted/booted. (?)

-Larry

[carmel_andrews]

Was the XF 551 the 'reworked' version of the external 'SF' model disk drives for the ST, As they seem to be similar and have similar electronics

 

Their again i was told or heard that Atari was going to do an A8 version of the external 'SF' st diskdrive (Perhaps the XF 551 was the result of this)

[jvas]

Have you tried to fill the 3.5" disk beyond 40 tracks? It should not work. But up to 40 tracks -- should be same as the old 5-1/4".

Evidently your 551 board was OK, if you swapped the mech and it formatted/booted. (?)

-Larry

 

Yes, it seems that the electronics itself is OK. I thought that I wouldn't be able to use a 3.5" mech without OS upgrade. I haven't tried to write beyound 40 tracks yet. Which dos supports that?

[+Larry]

Have you tried to fill the 3.5" disk beyond 40 tracks? It should not work. But up to 40 tracks -- should be same as the old 5-1/4".

Evidently your 551 board was OK, if you swapped the mech and it formatted/booted. (?)

-Larry

 

Yes, it seems that the electronics itself is OK. I thought that I wouldn't be able to use a 3.5" mech without OS upgrade. I haven't tried to write beyound 40 tracks yet. Which dos supports that?

 

Glad your board was ok. MyDos, Sparta, Top Dos, Super Dos, and probably several others that I'm less familiar with. But you do need to change the rom before these will be successful in reading/writing tracks 41-80.

-Larry

[jvas]

Have you tried to fill the 3.5" disk beyond 40 tracks? It should not work. But up to 40 tracks -- should be same as the old 5-1/4".

Evidently your 551 board was OK, if you swapped the mech and it formatted/booted. (?)

-Larry

 

Yes, it seems that the electronics itself is OK. I thought that I wouldn't be able to use a 3.5" mech without OS upgrade. I haven't tried to write beyound 40 tracks yet. Which dos supports that?

 

Glad your board was ok. MyDos, Sparta, Top Dos, Super Dos, and probably several others that I'm less familiar with. But you do need to change the rom before these will be successful in reading/writing tracks 41-80.

-Larry

 

Would an 5.25" mech from the PC work also?

[+Larry]

Would an 5.25" mech from the PC work also?

 

Please re-read my post #4.