http://www.ghisler.com/efaqport.htm

So in short, it never uses any EPP or ECP mode and the cable it uses is a very basic 4-bit (+clock) parallel cable, meant for standard parallel ports. It does not even require bidirectional PS/2 style mode. I also think you can't use EPP between two PC's, but ECP could be possible.

75 kilobytes per second through that seems quite OK for the cable type.

Well that sucks 😁

I saw people get 2MB/s between PCs in various threads.

Stojke wrote:

By my understanding, Bi Directional is the same thing as PS/2 which is the same thing as EPP/ECP mode who's maximum transfer speed should be from 512kB/s to 2560kB/s.

Standard mode is the ability for a PC to send 8 bits at a time, but only read 5 bits back. The five bits are the various control lines that the attached device can toggle. Usually only four of the five available lines are used.

This is a pretty expensive operation - you have to poll the parallel port intensively to do this.

Bi-directional (PS/2) mode allows you to send and receive a byte at a time without using the control lines. This improves read speeds by 2x.

EPP is a vast improvement - it is bidirectional, but the hardware does more of the grunt work of polling the port and handshaking with the other device, offloading it from the CPU.

ECP is the best; the parallel port does EPP like transfers and also uses DMA to let the main CPU do something else.

Pretty much any machine can do bi-directional; modifications for old PC, the PCjr, etc. were readily available. EPP gives a great speed boost on top of that. The DMA feature on ECP is probably overkill.

I dunno about using Total Commander for copying files over parallel port. I always used FastLynx, XtreeLink, or Interlnk/Intersrv that comes with DOS, and I remember they were much faster than 75KB/s using a parallel cable..