View Full Version : Atari mfm hard drive failure

May 31st, 2015, 09:53 AM
My mega file 20 has died , the mfm st220 just won't seek anymore - clearly not built to last :-)

Will any mfm sized drive do ?

Atari used 20,40 and 60 I think


May 31st, 2015, 03:18 PM
Assuming you meant the ST-225, any MFM drive that mimicked its 20mb parameters will work.

June 1st, 2015, 07:19 AM
yes i do , typo on my part.

ST225 MFM , I've just read an article from back in the 80s Popular computing ran a story about upgrading to 42mb MFM on the same Metafile 20 as mine.

So maybe i can do that. shame i can't see the data on this old drive , i may video it :-)

June 1st, 2015, 07:39 AM
ST-225's were generally known to be quite reliable, of course, we are nearing the other side of the bathtub curve.

My Megafile 30 originally had some nasty 30mb RLL thing from Seagate that was missing when I originally found it. It worked fine with a 30mb rated RLL Miniscribe, though it is as unreliable as anything else using an RLL miniscribe in it.

June 1st, 2015, 08:31 AM
Have you tried the old tricks of freezing it, or physically opening it / unsticking the head, at least to see if you can retrive whatever's on it?

June 1st, 2015, 10:45 AM
Its clicking when trying to seek , the drive spins up and the heads try to read (I've had the lid off) but it just won't read.

The Atari hard drive HDX tools won't even see it.


June 2nd, 2015, 12:16 PM
You can put in any MFM/RLL harddrive into your megafile 20 / SH 204 / SH 205. You only need to edit a textfile on the HDX diskette called WINCAP if your drive is not already there. It's syntax is described in the file itself. RLL drives will only be formatted in 17 sectors, that means only 2/3 of it's capacity. To use RLL format you would need a Megafile 30/60 which is having the RLL capable disc controller.

June 2nd, 2015, 12:19 PM
i didn't know that , thanks. I'm kind of surprised the drive isn't found at all.

June 2nd, 2015, 09:55 PM
The integrated adaptec controller in a sh/megafile first waits the mfm/rll drive to initialize. If it is not ready, the controller waits endless...

June 3rd, 2015, 12:53 PM
oh right , thats why it just sits there then. Pity i can't get the data off it - never mind.

June 6th, 2015, 03:06 PM
So I've managed to get a western digital 20mb mfm drive and I've popped that in, now interestingly it shows either 3 or 4 bombs at boot or it boots up but the floppy stops reading. If I reboot the mega St with the mega file turned off - the floppy reads again... Most odd.

The hard drive spins up ok and appears to seek. On the odd occasion that HDx ran, no hard drive was detected. Could be another bad drive of course.

well I've had some interesting results.

It seems its a known problem, if a device is attached to the ST without a drive in it or a faulty drive it will stop floppy access.

Also i have it kind of running now , with the ST225 drive. it will detect and semi format the drive but it fails at the very end and cannot continue. Thats ok i know its faulty.

As for the western digital ....it is not detected at all. So time to play about and see if i can solve this.



needed the last HDX-5.0 to detect and format the drive , it took 4 attempts but its done it. system installed and running :-)


July 3rd, 2015, 04:43 PM
A bit late now, but to bypass the HDD on boot up, press and hold Alt until you see the system access the floppy drive.

Well done on getting it going :D


July 16th, 2015, 12:16 AM
In order to get TOS to recognize the drive, a HD driver package will be needed. Here are some of the more popular packages:

AHDI is Atari's Hard Disk Driver and can be obtained free from any good FTP server (see section 2.2.3). However, it appears that it is not as capable and efficient as some 3rd party driver software.
ICD Tools: provided with ICD host adapters (see section 3.2.2). Quite efficient and easy to install but has a few compatibility problems with advanced setups (alternative operating systems etc).
HD Driver: Probably the best commercial driver available. It can be bundled with some host adapters, and it also includes support for removable media, such as ZIP or JAZ drives.
CBHD: another freeware driver, probably not as good as the two commercial ones, but certainly better than AHDI. Only german docs are provided, so setup might be a bit tricky.

AHDI 6.06 Utility Disk


It also seems that some drivers are more suited to one type of drive whereas they can have problems with other drives. A good idea might be to ask the newsgroups or the software vendor for any compatibility issues before buying.