Archiving Software

RTFM (In this case the IBM Options and Adapters Technical Reference). The IBM PC disk controller most certainly supports 4 drives as standard. There's an 8 bit output port that controls the drive select and motor-on lines for the 4 drives. Because of the 'IBM Twist' to get seperate motor-on lines to the drives, you can only have 2 drives on a cable (the PC disk controller has a 34 pin card-edge for the internal drives and a DC37 for external drives). Later controllers, as used on the PC/AT, etc, only had one connector for the intenral drives, and only supported 2 drives. But if you look at the bit definitions of the drive control output port, you'll see 'gaps' in it. Those were the bits for the external drive select and motor-on signals. It's odd, but I've released a number of classic computer-related programs under the GNU license and have never had any stupid questions like this. I do sometimes get interesting questions from people who know what they are doing and who want to do something totally different with it. Rememebr that the GNU license does not require you to support anything. You have just lost any respect I may have had for you. -tony