stever@tektronix.UUCP (02/25/84)
alpha... This is my experience with half height drives: YES, on the IBM PC you can set the system switches for the number of drives you have from 0 to 4. I have mine set at 4 with two physical drives, and one or two RAM drives depending upon my needs. My AST SUPERDRV software allows me to assign the RAM disk(s) to any of the four drives. You don't need another controller board for the extra drives as was implied by someone. If you acquired the IBM PC with only one drive, the data cable should have a have connector on it for a second drive, and there should be a second power connector inside. For three drives you need a power splitter cable and an external data cable. For a 4th drive you need another power splitter cable. The external data cable plugs into the connector on the outside of the IBM disk controller board, and then is routed back inside the system unit. It should have connectors on the other end for C and D drives. Apparat and many other disk drive vendors should have both the power splitter cables and the data cables. You might have to put your original full height drive on the right hand side because the data cable plugs in on the opposite side from the full height on many half heights, making the distance between the A and B drives (where one is full and one half height) twice the width of a standard drive. The cable supplied with the IBM PC was not designed for that distance. I have configured such a system with two double sided half heights and one single sided full height. I have had "50-50" experience with half heights. Early on in the game I bought 2 TEACs and 2 HITACHIs for two different IBM PC systems. The A drives worked great! The TEAC makes a sharp clicking sound and the HITACHI was so quiet I was always checking it! However, the B drives of both types worked only about 20% of the time. After several shipments back to Apparat and several wiped-out diskettes I have given up on the B drive except as a scratch drive. Apparat was very cooperative, but I feel they did not have the technical knowledge to solve this problem. All they could do is recalibrate and clean the heads. It is a funny situation. Recently, I was forced to use my B drive to dump a source listing from a compiler. (i.e. Needed 3- 320K drives to do a FORTRAN compile--it is large program!) It worked perfectly in writing an 85k file. A BASIC test program writing, reading, and erasing 40 files works everytime. But when I start trusting it, I lose data and sometimes the disk is not useable. No pattern to it at all. Two final comments. The HITACHIs got replaced by Shugarts and I understand everything is working fine. I would not recommend HITACHIs to anyone mainly because they have a plastic point that brushes the diskette right next to the write protect notch. When you cover that notch you have to off-center the tape or the plastic point sticking down will catch on it---very annoying! If you will look closely at the Amdex drives in ads, you can see the plastic point! Buyer beware! If anyone can tell me their secret for operating a TEAC half- height as a B drive, I would be VERY happy! Otherwise, I will soon replace my TEACs with Shugarts or CDCs.