koonce@ragu.berkeley.edu (tim koonce) (09/18/88)
Finally got a hard disk controller to put into my Burke & Burke interface, but am having a LOT of problems getting the system to run reasonably. Can anyone help? Here's the hardware setup: A Y-cable with the Disto SCII, B&B hard disk interface with Adaptec 2072 controller, PBJ 2-sp pack, and Speech/Sound cartridge. After I had some problems earlier, I modified the SCII (according to instructions from Tony Distefano) to disable the MEB, which I had suspected was causing problems due to addressing conflicts. I also cut the CTS* line on the B&B interface, and pulled it high through a 1k resistor, to prevent ROM conflicts. I then reassembled everything and re-formatted the hard disk. Here's the symptoms. After successfully formatting the hard disk, I've been trying to copy some stuff over to it. Periodically, attempts to read or write the hard disk cause the program to hang. Usually, this happens in the shell when I try to execute something from the hard disk. As an example, to test it, I copied 'ar' and a large archive over to the hard disk, which seemed to work. I then changed my execution and data directories to the hard disk. Typing 'ar' at the shell prompt simply hung. From another window, mdir did not show 'ar' in the module directory, but 'procs' did show 'ar' executing, with zero memory. Attempts to reference the hard disk from the second window also hung, and, since I only had two windows open, I had to reboot. These hangs seem to be infrequent at first, but occur more often once I actually get some stuff onto the disk. Such hangs also seem to occur every time I try to execute a program of any length from the hard disk. Short utilities, such as 'dmode', seem to load and execute fine. Longer utilities fail consistently. This also seems to happen whenever I simply 'load' one of these longer utilities (it appears in the 'procs' listing, but not in the 'mdir' listing). First question: Under what conditions will the hard disk driver simply stop? I've noticed that the Tandy floppy driver will simply hang if there is no disk available. Will the B&B driver act similarly if the hard disk fails to respond? What might cause the hard disk to not respond? The only possible hardware problem that might remain (I hope) is that I am (due to some incorrect information I got when I first got the drive) using an RLL controller with an MFM drive. For obvious reasons, this might take a little while to correct. (Anyone want to swap an Adaptec 2072 for a comparable MFM controller?) Does anyone know of any reason why this might cause such serious problems? (I would expect the occasional CRC error or bad sector, but a complete hang is a little severe.) Any help is appreciated, Tim Koonce koonce@math.berkeley.edu ...!ucbvax!math!koonce