==> SIO2PC, by Nick Kennedy

From the SIO2PC home page:

SIO2PC is a hardware & software package interfacing the 8-bit Atari to PC
compatible computers.

The original idea was to have the PC emulate Atari disk drives so Atari
programs could be stored on the PC's hard (or floppy) drives.  It turned out
to be quite successful.  About 95% of my work was in the software, but a
hardware device to convert logic levels was also necessary.  This device is
now commonly referred to as an SIO2PC cable.

Features:
  -  Emulates 1 to 4 Atari disk drives
  -  Store your Atari files on PC hard or floppy drives
  -  Boot from the PC, real drive not needed to start-up
  -  No software or drivers required for the Atari;
         no conflicts: use your favorite DOS
  -  Twice as fast as an Atari 810 drive and more reliable
  -  Co-exists with real drives in the Atari daisy chain
  -  Compatible down to the hardware level: use sector copiers, etc.
  -  Print-Thru captures Atari print-out and routes to PC's printer
  -  Convert Atari files to PC files and vice versa

http://pages.suddenlink.net/wa5bdu/sio2pc.htm

Another source for various SIO2PC cable design plans is Clarence Dyson's page
at http://www.wolfpup.net/atarimods/

Another (Czech language): http://raster.infos.cz/atari/hw/sio2pc.htm


==> Atari810, by Dan Vernon
A disk drive emulator in the tradition of SIO2PC, for the Windows NT/2000/XP
platform.

http://retrobits.net/


==> Atari Peripheral Emulator (APE), by Steven Tucker

David A. Paterson writes:
"Steven J. Tucker took SIO2PC one better and wrote new software.
The Atari Peripheral Emulator (APE for short):

- lets your PC act as high-speed drives.
- It lets you print to your PC printer.
- And it lets you use your PC modem on the 8-bit."

http://www.atarimax.com/


==> SIO2Linux, by Preston Crow

Pavel Machek made an initial attempt at communicating with the Atari through
an SIO2PC cable using Linux's serial port drivers. He came up with a simple
floppy emulator, femul.c.  I rewrote that to add a bunch of features:

* No kernel modules.
  Unlike the AtariSIO project, this is just a simple user-space program that
  uses a serial port device.
* Create new dynamically sized images
  Each image starts as a 3-sector image file, but grows to accommodate the
  highest-numbered sector written.
* Mount your native file system as an Atari disk
  It's read-only for now, and it doesn't support subdirectories, but each
  file is mapped to a different starting sector, and as that sector is read,
  it automatically maps in the rest of the file.

http://www.crowcastle.net/preston/atari/


==> Sio2OSX, by Mark Grebe

Sio2OSX is a peripheral emulator for the Atari 8-bit computers that allows
the Atari computer to use an OSX based Macintosh as a disk drive, a cassette
drive, and a printer. Sio2OSX performs functions similar to APE or SIO2PC on
Windows based computers.

http://www.atarimac.com/sio2osx.php


==> Multi-platform Distributive Operating System Professional for Atari,
    by Krishna Software (Krishnasoft)

MPDOS Professional for Atari Features:

 o Joystick simulation (2-button and single button)
 o Digitized Paddle simulation (just extreme values)
 o Allows for using PC joystick or keyboard to simulate Atari joystick
 o Works with Atari 5200 (using Digital Joystick Adapter)
 o Keyboard simulation (supplied software driver is needed)
 o Simulates up to 4 Atari disk drives (D1:, D2:, D3:, D4:)
 o Simulates Atari cassette player (C:)
 o Includes easy to use parallel port cable (plug and play)
 o Hardware level simulation (no drivers required, except for keyboard)
 o Supports PC video overlay window
 o KDOS4-- a fast binary file uploader
 o Multimedia CDROM included (runs on PC and Atari using distributive
   programming)
 o Built-in editor for creating Atari ASM and Atari BASIC source files
 o 6502 Assembler (compile and upload directly to Atari)
 o Sample source code
 o DOS-based utilities including 6502 disassembler
 o Simple GUI interface for simulating peripherals, compiling, and uploading
 o On-line 100+ page manual with technical and general information