rjb@cbnewsj.ATT.COM (richard.j.bavier) (12/21/89)
I have a problem similar to one I saw reported earlier. I have a 16B that has been upgraded to a 6000(PAL changes). I wanted to replace the hard disk I am using. Currently I have a ST225 that works fine. I want to replace it with a CDC 86 meg drive. I have been told the drive uses the ST506 interface and is rated at 28ms. When I try to format the drive I get the error message "drive not ready". When I put the drive in an MS-DOS machine with a Western Digital controller it works fine so I know I have the drive select jumper set correctly. I have tried it with and without the terminating resistor. The machine works fine with the original 15 meg drive and the ST225 so the machine seems ok. I have tried different cables in case one of the connectors was marginal. Any ideas would be helpful. Thanks in advance. Rich Bavier attmail!rbavier (201)576-2665
uhclem@trsvax.UUCP (12/22/89)
<> B>I have a problem similar to one I saw reported earlier. I have a 16B that B>has been upgraded to a 6000(PAL changes). I wanted to replace the hard B>disk I am using. Currently I have a ST225 that works fine. I want to B>replace it with a CDC 86 meg drive. I have been told the drive uses B>the ST506 interface and is rated at 28ms. When I try to format the B>drive I get the error message "drive not ready". When I put the drive If the drive has more than 8 heads, you will only be able to use 8 heads. In addition, you must tape pin 2 on the "Control" cable on the drive. (That's the 34 pin cable that goes to every drive.) You sometimes have to do this on drives that have 8 or less heads anyway as the drives really have a ST412 interface (only difference is pin 2) and the electronics may honor pin 2 (Head select 2^3) even if the drive doesn't have that many. Standard chips, you know. If the drive has more than 1024 cylinders or an abnormally high step time (NOT seek time), you might have to start the format twice in a row (DO NOT RESET between attempts) to get the heads all the way back to cylinder 0. If the format runs for a moment or even several minutes and then reports it is not ready, cover pin 2. Nearly 100% of the drives made since 1985 with ST506 interfaces really have ST412 interfaces. The manufacturers apparently thought no one could cope with a different number. The IBM AT hard disk adapter (including the original from 1985) uses ST412. On early models there was a strap you changes if you really had a yucky old ST506. Nowdays I don't think they bother. Line 2 was Reduced-Write-Current, which nearly all drives with microprocessor control can determine for themselves and in ST412, the line is used to select additional heads (>8). If you have a copy of TRSDOS for the Model II/16 laying around, boot it, run debug and do this: (Sorry, the TRSDOS-II BASIC does not have IN/OUT.) OUT to port 0xc0 0x0c (enable port) OUT to port 0xce 0x08 (512 byte sectors, Drive 0, Head 0) IN from port 0xcf (read status port) If the value you read is 0x50 or just has Bit 6 on, the controller believes the drive is READY. Bit 4 indicates the SC (Seek Complete) line is high, another good sign of a properly connected drive. If you want to try a restore, OUT to port 0xcf 0x1c (restore to cyl 0 at 6.0 msec step) IN from port 0xcf (read status port) Depending on where the heads are, it may take some time for that command to complete. (Bit 7 in 0xcf is on when the controller is still working on it.) When it does complete, you should read 0x50. This indicates that a good part of the drive and its host interface are working. <This information is provided by an individual and is not nor should be construed as being provided by Radio Shack or Tandy Corp. Radio Shack/Tandy Corp has no obligation to support the information provided in any way. It just happens to work that way and its in the technical manual.> "Thank you, Uh Clem." Frank Durda IV @ <trsvax!uhclem> ...decvax!microsoft!trsvax!uhclem ...hal6000!trsvax!uhclem "'BATMAN(TM)(R) The Cereal!' Made by Ralston Purina who for some reason did not name it 'BATCHOW(TM)(R)(C) The Cereal!'." - Me
bill@bilver.UUCP (Bill Vermillion) (12/22/89)
In article <2968@cbnewsj.ATT.COM> rjb@cbnewsj.ATT.COM (richard.j.bavier) writes:
->I have a problem similar to one I saw reported earlier. I have a 16B that
->has been upgraded to a 6000(PAL changes). I wanted to replace the hard
->disk I am using. Currently I have a ST225 that works fine. I want to
->replace it with a CDC 86 meg drive. I have been told the drive uses
->the ST506 interface and is rated at 28ms. When I try to format the
->drive I get the error message "drive not ready". When I put the drive
->in an MS-DOS machine with a Western Digital controller it works fine so
->I know I have the drive select jumper set correctly.
You have the drives jumpered correctly FOR AN MS-DOS MACHINE. The Tandy's
are not MSDOS. Take a close look and you will find that the drives in most
MSDOS machines are selected as DRIVE ONE (NOT ZERO), and the cable does the
selection. Jumper the drive for drive select zero and your problems will go
away. Not using a CDC, but was using a Miniscribe (it ate itself one day to
the acompniment of the sounds of heads grinding on the platter) and is now and
internal Microlpolis. Just plug and go AFTER setting the jumpers correctly.
If you are using an external box the additional jumpers that Tandy used on the
orignal need to be matched.
--
Bill Vermillion - UUCP: {uiucuxc,hoptoad,petsd}!peora!tarpit!bilver!bill
: bill@bilver.UUCP