PCjs Machines

Home of the original IBM PC emulator for browsers.


IBM PC 20Mb Hard Drives

PCjs includes 20Mb drives in selected IBM PC AT and COMPAQ DeskPro machines, because both those machines support a 20Mb Drive Type with the following drive parameters:

615 cylinders
4 heads
17 sectors/track

yielding a capacity of 21,411,840 bytes (615 * 4 * 17 * 512), or 20.42Mb (since PCjs considers 1 megabyte to be 1,048,576 bytes).