CompuServe Thread

JP >> Has any one here ever tried to make an IBM disk drive work on the Amiga 1200. If anyone has any ideas let me know, I bought a teac drive capable of 2 meg diskettes […]<< Ok here's the deal…. The Amiga's floppy controller consists largely of the Paula & Gary/Gayle chips. This gives a DMA floppy controller capable of handling four 1-meg floppy devices, at the costs of the controller being intergrated into the motherboard. The Amiga floppy controller's maximum tranfer rate is 300Kps, which is pretty good considering that DSDD (1-meg, double-sided/double-density) tranfers at a rate of 250kps at 300rpm (rotations-per-minute) of the disk. Unfortunately, the DSHD (2-meg, double-sided/high-density) disks used by IBM/Clones tranfer data at 500Kps at 300rpm. This is too fast for the Amiga's controller to handle. Commodore solved this problem by having a special dual-speed, HiDensity floppy drive developped from them (by Chinon). This drive functions normally with DSDD disks, but slow down to half speed when using HiD disks (500Kps at 150rpm, gives a data transfer rate of 250kps). The disks still hold twice as much, but doesn't tranfer at twice the speed. The Amiga can format the HiD floppies at either 1.76Kb or 1.44Kb (PC format). You can still install an IBM HiDensity drive in the Amiga, but you will need to use the Amiga's interface standard, and you will only be able to use in in DSDD mode. If your interested in a HiDensity drive for the Amiga, you will need the Commodore dual-speed drive. You might be able too get the dual-speed internal drive (for the A4000) for $99 and use it in the external case. If you find the newer "low profile" version, you could use it to replace the A1200's internal drive. Ron. – ap'ing with AP. (Eagles may fly, but weasels aren't sucked into jet engines.)