Re: PC to Apple II disk drive

[Linards Ticmanis <ticmanis@gmx.de>]

Jack Tseng wrote:
> PC using parallel can communicates with Commodore 1541 (GCR) thur X1541 
> cable. X1541 cable looks really simple we can make.
> 
> Can we make the cable for Apple disk drive and PC parallel or serial?
> or buy the Apple disk drive adapter card for pc?

Commodore drives and Apple drives are very different.

The Commodore drive is itself a computer with its own CPU. It does all
the hard work itself. There is a complete DOS built into the drive --
the drive can organize files and directory without help. The interface
is a serial bus. To the computer the drive looks like a "character
device" (in Unix speak).

The Apple drive is only a drive, not a computer.
It is a real "block device". All the hard work must be done by the
computer. The computer must read the signal, interpret it to find
blocks, then interpret the blocks to implement files and directories.

The problem with the Apple drive is, it wants to send or receive one bit
exactly every 32 microseconds. No slower no faster. This is not really
doable with any "normal" pc interface. Maybe with parallel port in pure
DOS mode, but it's very difficult to get right.

Usually, you connect the PC to an Apple computer and then the drive to
the Apple computer. This is similar to the X1541 method - there is an
extra computer for the drive. In the 1541 it is built into the drive,
with Apple hardware you must add an external real Apple computer.

-- 
Linards Ticmanis