aburt@isis.UUCP (Andrew Burt) (08/13/87)
I was attempting to put a 360K drive [a Teac] from my Sanyo 555 pseudo-PC-clone
into my new AT-clone. The closest I got to getting the AT to recognize it
was that it would select correctly as drive B:, but any attempts to read
from the disk gave "not ready error reading drive b". I could "cd b:" [or
just b:] and get b shown as my current drive, but anything simple like
'dir' would give the above error. That was only after changing the drive
select jumpers on the drive itself (and running 'setup' of course).
The controller is a Western Digital, with provision for two floppies and
two HD's.
The only thing the manual for the AT says about adding a 360K drive is
essentially "plug it in". Does anyone know if the Teac's used by the Sanyo
are in some way unusable for AT's? Or how I should configure the drives?
I tried changing a number of the jumpers, on both the 360 and the 1.2Mb,
all to no avail. [Many worse results, but no successes.]
Any suggestions welcome...
--
Andrew Burt isis!aburt
Fight Denver's pollution: Don't Breathe and Drive.bshafer@udenva.UUCP (bshafer) (08/13/87)
It could be a terminator problem or an address problem or possibly
something to do with set up on your AT. It should work.
Call Dave Axtman (x2100) at Service and Microcomputer Support (SAMS - used
to be the computer store) and talk it over with him.
--
Usenet: ... {hplabs, seismo}!hao!udenva!bshafer
BITNET: BSHAFER@DUCAIR
Phone: (303) 871-2091
Mail: CaIR -- BA469, University of Denver, Denver CO 80208keithe@tekgvs.TEK.COM (Keith Ericson) (08/13/87)
In article <1918@isis.UUCP> aburt@isis.UUCP (Andrew Burt) writes: >I was attempting to put a 360K drive [a Teac] from my Sanyo 555 pseudo-PC-clone >into my new AT-clone... but any attempts to read >from the disk gave "not ready error reading drive b". > >Any suggestions welcome... Put a piece of scotch tape over trace #34 of the Teac drive's connector. This disables whatever the heck it is that Pin 34 does*. I've done this in all the AT Clones I've installed these Teac drives into (about a dozen) and it does the trick. keith * explanations invited; I've forgotten what pin 34 is for. Seems the 360Kbyte drives and the AT disagree as to the function...
enchant@oliveb.UUCP (Dan Crocker) (08/14/87)
In article <1918@isis.UUCP>, aburt@isis.UUCP (Andrew Burt) writes: > I was attempting to put a 360K drive [a Teac] from my Sanyo 555 pseudo-PC-clone > into my new AT-clone. The closest I got to getting the AT to recognize it > was that it would select correctly as drive B:, but any attempts to read > from the disk gave "not ready error reading drive b". I could "cd b:" [or I fixed exactly this problem by doing the following: Cut pin 34 on the edge connector of the 360k floppy (I know this probably makes you nervous). I'll bet you have a Western Digital WD1003-WA2 controller, right? Anyway, the reason for this is that pin 34 has different meanings on the 360k and 1.2mb floppies. On the 360k, it is the drive ready line and on the 1.2mb it is the disk change line (it means that the diskette has been removed from the drive). The system uses this signal to decide whether or not it needs to check the capacity of the diskette in the drive (360 or 1.2) The problem comes when you connect the 360k drive. The controller interprets pin 34 as a diskette change line (obviously a dumb thing to do) and, since it is always true (the drive is ready), dos gets confused and reports a drive not ready error (its really not that kind of error). If you don't want to cut this line at first, you can just put a piece of tape over the pin so that it doesn't make contact. Also, some drives have a jumper that allows you to disconnect this pin from the interface. You can look for that too. Hope this helps. dan -- Here comes the supernatural anesthetist If he wants you to snuff it All he has to do is puff it He's such a fine dancer
fyl@ssc.UUCP (Phil Hughes) (08/18/87)
In article <1918@isis.UUCP>, aburt@isis.UUCP (Andrew Burt) writes: > I was attempting to put a 360K drive [a Teac] from my Sanyo 555 pseudo-PC-clone > into my new AT-clone. The closest I got to getting the AT to recognize it > was that it would select correctly as drive B:, but any attempts to read > from the disk gave "not ready error reading drive b" I got burned by this one too. In my case, I had added the drive to a UNIX system on an AT. UNIX worked fine with the 360K drive but MS-DOS and the IBM diagnostics didn't. The answer turns out to be what to do with pin 33. Us normal people expect all the odd pins to be ground but pin 33 is used in the AT to tell it about 360K drives. On my drive there was a jumper on the circuit board that I had to cut. If yours doesn't have one you should be able to stick tape over the contact finger so you don't need to butcher the drive. Good luck. -- Phil Hughes, SSC, Inc. P.O. Box 55549, +----------------+ Seattle, WA 98155 (206)FOR-UNIX | NO CONTRA AID! | ...!uw-beaver!tikal!ssc!fyl +----------------+
wtm@neoucom.UUCP (08/18/87)
On 360 K drives, pin 34 is the select lead when the drive is configured as unit 03. Most PeeCompatibles configure the drives as unit 00, and flip-flop a few wires in the cable to differentiate between drives A and B. On such a drive, pin 34 is intended to be an input, and the appearance of this lead to an AT computer's connector is indeterminate, and can cause unreliable operation. On 1.2 meg drives (and 720 K micro floppies too), pin 34 is a media change output to the computer. Every time you insert or remove a disk, a logic pulse appears on this lead. To get a 360 K disk to work on your AT, you have to either put a small piece of tape between the pin and the drive connector or else slice the trace on the drive circuit board leading to pin 34. Be sure you know what you are doing in the latter case! (Actually I prefer the latter method.) Second, you have to run your computer's diagnostic program to inform the non volitile RAM what sort of drive(s) is/are connected. At this point, everything should be OK. Note that the AT BIOS watches the media change lead on the drive to see when you swap disks. Normally, the disk's File Allocation Table (FAT) is cached in RAM. Swapping a disk necessitates re-reading the FAT. On 1.2 meg drives, pin 34 does the deed. On 360 K drives, there is no media change signal, thus the BIOS re-reads the FAT regardless, whenever more than 1/2 sec. has elapsed since the last disk access. If you were some sort of super-human and could change diskettes faster than 1/2 sec, you could wind up with a hoplessly scrambled 360 K disk if DOS wrote with the wrong FAT in the RAM cache. Hope this is helpful, Bill (wtm@neoucom.UUCP) Note that Teac, Toshiba, and probably other companies make 360 K dirves that can be used on an AT without any slicing and dicing of pin 34 required.
enchant@oliveb.UUCP (Dan Crocker) (08/20/87)
In article <666@neoucom.UUCP>, wtm@neoucom.UUCP (Bill Mayhew) writes: > > On 360 K drives, pin 34 is the select lead when the drive is > configured as unit 03. Most PeeCompatibles configure the drives as > unit 00, and flip-flop a few wires in the cable to differentiate > between drives A and B. On such a drive, pin 34 is intended to be > an input, and the appearance of this lead to an AT computer's > connector is indeterminate, and can cause unreliable operation. > > Table (FAT) is cached in RAM. Swapping a disk necessitates > re-reading the FAT. On 1.2 meg drives, pin 34 does the deed. On > The conclusion is right, but the explanation is wrong. 1. Pin 34 on the 360 drives is drive ready which is an output that is basically always true. The problem is that this output is interpreted to mean "diskette changed". The way to reset this condition (on a 1.2 meg drive) is to issue a step to the drive. With a 360K, the system tries to reset this line but never succeeds thus causing the error condition. 2. The "IBM" way of selecting drives is to set the drive as device #2 (starting from #1; in other words, the second floppy) and swap selects on the cable. 3. The other thing that happens with a 1.2 meg drive when the disk is removed is to re-check the data transfer rate for that drive. With a 1.2 meg disk in a 1.2 meg drive, the rate is 500 kb/sec and with a 360 in a 1.2, it is 300 kb/sec. The controller must be programmed differently in order to read these different combinations. dan -- Here comes the supernatural anesthetist If he wants you to snuff it All he has to do is puff it He's such a fine dancer