rjb@cbnewsj.ATT.COM (richard.j.bavier) (01/08/90)
Due to the number of requests for the results of my attempts to replace the hard disk on my 16B/6000 I am posting to the net rather than answer each person individually. First I would like to thank everyone that sent me their suggestions. I was really surprised at the number of offers of help. Helpfull Hints: 1) Know the interface(ST506 - ST412). The difference is pin 2 on the 36 pin cable. On ST506 it is reduced write current. ST412 uses it for >8 heads. The symptoms I saw was that after 50% of the format was complete almost every head and cylinder had an error. This happened no matter how many heads and cylinders I told format the drive had. My guess is that after 50% of the drive is formatted, reduced write is turned on. On an ST412 interface drive you are now trying to format Head + 8. Since the drive I was working with had 9 heads(0-8) I did not get the error on head 0. To correct this you must shield pin 2. The suggestions I received ran from placing a piece of tape over etching for pin 2 on the connector at the drive, to bending pin 2 on the circuit board. 2) If the format fails to start check to make sure that the drive is set correctly. I had test formatted my drive under MS-DOS doing this may require you the change the jumper for the drive select. Also check to make sure the card is seated correctly in the backplane. This is more a problem for the original Model 16. Check cable orientation(pin1 to pin1). If this fails, try to format with TRSDOS if you have a copy available. You do not have to wait for the formating to complete. I waited about ten minutes and then rebooted. 3) The maximum drive configuration is 8(0-7) heads and 1024 cylinders. If you have a larger drive you will not be able access the extra space without a different controller and software. In my case the drive has 9 heads and 1160 cylinders. My experience: I could not even get the format to start. So my first solution was to attempt a format with TRSDOS. After that I then had problems due to the drive being ST412. This was corrected by shielding pin 2 on the 36 pin cable. So far the drive has been working fine. Again thanks to the many offers of help. Rich Bavier attmail!rbavier