Opus Discovery - problem reading disks
Hello,
I recently got an Opus Discovery 1 but unfortunately for me it seems to be temperamental. :-(
The ZX Spectrum that is connected to it powers up fine but when I do CAT 1 on a double-density disk I get the following error message:
g Disk I/O error, 0:1.
The same message is also obtained at the end of a FORMAT command, i.e. the format procedure is initiated but at the end I get the above-mentioned message instead of the classic o.k. ZX Spectrum message.
Sometimes, I get the Opus to work and display the contents of a disk after I do a CAT 1. Also, I get it to format a disk correctly without any issues and this is why I said it is temperamental.
Let me assure you that my ZX Spectrum works fine as I have tested it using a wafadrive with no issues, so it must be something wrong with the Opus.
Any suggestions please? What might be the problem?
Thank you in advance for your help!
Kind regards,
Yannis
I recently got an Opus Discovery 1 but unfortunately for me it seems to be temperamental. :-(
The ZX Spectrum that is connected to it powers up fine but when I do CAT 1 on a double-density disk I get the following error message:
g Disk I/O error, 0:1.
The same message is also obtained at the end of a FORMAT command, i.e. the format procedure is initiated but at the end I get the above-mentioned message instead of the classic o.k. ZX Spectrum message.
Sometimes, I get the Opus to work and display the contents of a disk after I do a CAT 1. Also, I get it to format a disk correctly without any issues and this is why I said it is temperamental.
Let me assure you that my ZX Spectrum works fine as I have tested it using a wafadrive with no issues, so it must be something wrong with the Opus.
Any suggestions please? What might be the problem?
Thank you in advance for your help!
Kind regards,
Yannis
Post edited by yannis_uno on
Comments
1. have you tried a disk-head cleaner?
Yes... no difference.
I don't have the impression that the problem is due to a dirty reading head.
Thanks!
Hm.. although I haven't checked I thought that the opus disk drive has a servo motor (i.e. purely mechanical operation). Does it have a belt? Can someone confirm? Shall I check?
Other possible problems: bad disk(s), wrong density (use DD) , magnetic fields from TV.
1. Boil the belt in a pan of water. This softens the rubber and also shrinks it very slightly giving it back some of its elasticity.
2. Rub a raisin (yes, the thing you get in packets of nuts and raisins) on the belt. the natural resins give the belt grip.
Not permanant fixes but ones that I've used very successfully on many occasions with slipping belts.
:smile:
I am using the correct type of disks i.e. DD. The disks are o.k. at one occasion I got the drive to format them successfully. Sometimes it works, others doesn't, remember? :smile:
Thanks!
Very handy solutions but as roko said, no belt :razz:
Hm... I wouldn't know and besides I don't have an old DD 720kb floppy drive in my possession. Thanks!
if the OPUS Discovery uses a standard UART for its floppy drive, then you can modify a High Density (1.44MB) floppy drive by removing the high-density floppy disks sensor (its a small spring-loaded pin...
hell I could dig one of them up around here and modify it and send it you for the cost of postage if its possible for it to work with an OPUS Discover.
Looking at the schematics it certainly looks like it would. The OPUS Discovery uses a common WD1770 IC Floppy Disk Controller.
Of course if you are brave enough to open up the OPUS Discovery - take some pics of the drive, connectors and cable, I am sure I could help more.
If memory serves the OPUS Discovery can handle two Floppy Drives
I will try that and post back, thanks!
Which means a standard PC DD one would probably not work.
This is only supposition, but from my experience:
* Most 40-track drives use a RDY signal instead of DSKCHG. The Discovery would never get the ready signal so wouldn't do anything.
* 40-track drives are double-stepped - but an 80 track drive will still work, you just won't be able to read disks formatted on your 40-track
* Using the double-sidedness shouldn't matter because the controller is just telling the drive to use side A anyway.
* PC drives are jumpered to unit 1. You'll need to use a twist cable.
It's not all bad news, though... I'd strongly suspect an Amiga drive would work as they're DD and use a RDY signal. You'd still not be able to read old disks, though - they're 80-track.
Yannis, if you want me to have a look inside, let me know - I can try your mechanism with my Discovery drive. And I can upgrade your ROM to 2.2 in the process if you're using older and want me to.
Now to add a little more WIN, theres a really Nice Developer in the Amiga Scene under the name of Ian Steadman. He developed a very cheap Floppy Drive interface board, that allows PC Drives to be used on Amiga's
This interface corrects the RDY signal thats needed.
(image from www.ianstedman.co.uk)
(image from www.ianstedman.co.uk)
Unfortunately Stedy has sold out of the current development, but I am sure will be doing a new version run soon - for project details (if you are not scaired of a soldering iron) click here
Slightly off topic there is a discussion and development to allow for High Density drives to be used with the Amiga as High Density, but that wont relate to the case here unless you are a bit of an Amiga Fan as well.
I will have a Google over the 40-track-stepped drives and see if there is a bit of magic we can use to appropriate this activity on a 80 track unit.
That may help a bit!
Incidentally, would there be any problem connecting a Discovery to an Issue One Spectrum..?
Data written on the 40 track drive can be read on both. Data written on the 80 track drive is only readable if it's on a freshly demagnetised disk, or if the disk has only ever been used for double-stepped writing. Otherwise the wider 40 track head will see two narrow tracks of different data at the same time and return junk. So if you write to existing 40-track media on an 80-track drive, it'll become unusable on the 40-track drive!
It'd be easier to switch to modern drives for everything, and convert the existing 40 track media. Then you can read and write on either without any issues. On a Windows desktop PC, first read the existing 40-track disk, double-stepping the heads: Then write it back out to a new DD disk as normal:
you sir, are a legend!
Ian,
the opus weights a ton. Sending it and getting it back would cost me ?15-20.
The ROM version is the 2.2 (if I remember correctly, it definitely had a 2. in front). I will have to cross-check.
I doubt it, as I got it working for an instance - I could format, read, and write on a DD 720kb disk. The drive is temperamental, most of the times giving that read error message that I posted. I will also be getting another ZX Spectrum (not an issue 1) from a friend of mine to rule out that my ZX Spectrum is not the problem.
Thanks!
Because 80 Tr drives use smaller and weaker magnetic trails they cannot use disks with the wide 40 Tr trails on it. Even formatting did not remove the old magnetics from my expensive IBM disks. Once upon a time...
DD drives that have a jumper to select drive nrs. and still do not react, are probably coming from PC and therefore have the Motor On signal (mis)used as Drive Select.
When a jumper allowes you to choose between MO and MS, then MO is your friend.
M1 - ?
M2 - Spindle motor controlled by the Drive Select signal
MO - Spindle motor controlled by the Motor On signal
MM - Motor start-up by the Motor-On signal
MS - Spindle motor controlled by the Drive Select signal
DC - Disk Change is the signal on pin 34 of the interface connector
RY - Ready is the signal on pin 34 of the interface connector
SR - Issues the Standard Ready signal on pin 34
IS - Front LED controlled by the Drive Select signal
IU - Front LED controlled by the Ready signal
IR - LED on: Drive Select * Ready
Let me know if I can help, anyway.