==> 1050-2-PC, by Nick Kennedy
A device used to allow the PC to communicate directly with an Atari disk
drive.  It requires hardware which is very similar to the SIO2PC but
configured differently.  It allows direct sector I/O with the Atari drive and
can be used to create disk images which will emulate copy protection schemes
when run on SIO2PC.
More 1050-2-PC information: http://pages.suddenlink.net/wa5bdu/1050.txt
SIO2PC home page: http://pages.suddenlink.net/wa5bdu/sio2pc.htm

==> APE ProSystem, by Steven Tucker
Two components:
- The ProSystem hardware is a cable designed to allow connection of a stock
  1050 disk drive directly to a PC's serial port for use by the companion
  ProSystem software.
- The ProSystem software program is used to create (protected or unprotected)
  .PRO format disk images.  These disk images can then be accessed by the
  Atari using Steven Tucker's Atari Peripheral Emulator (APE) cable/software.
http://www.atarimax.com/
Additional ProSystem cable design:
 - Atarimax Universal SIO2PC/ProSystem interface (Steven Tucker)
   USB or RS232/Serial versions
   http://www.atarimax.com/sio2pc/documentation/

==> AtariSIO driver and utilities V0.30, by Matthias Reichl
AtariSIO requires a 2.2, 2.4, 2.6 or 3.x series Linux kernel (with enabled
module support) and a serial port with a 16550 or 16C950 compatible chip.
Consists of:
- A kernel module to handle the low-level part of the Atari SIO protocol
- atarixfer
    Used to read/write disk images from/to a Atari drive connected to your
    Linux box with an 1050-2-PC cable.  An APE ProSystem cable will also work,
    but you have to add the command-line switch "-p".
- atariserver
    An SIO-server, like SIO2PC or APE for MSDOS-machines.
- adir
    List the directory of an image
- dir2atr
    Create a disk image from a directory of files on your PC
AtariSIO supports the following interfaces:
- One chip SIO2PC (with MAX232), command connected to RI
- One chip SIO2PC, command connected to DSR
- One chip SIO2PC, command connected to RTS
- 1050-2-PC (with MAX232), command connected to RTS
- Ape ProSystem cable (with 14C89), command connected to DTR
http://www.horus.com/~hias/atari/