On 16/02/2018 01:11, John Rumm wrote:
On 15/02/2018 18:18, Huge wrote:
On 2018-02-15, John Rumm wrote:
On 14/02/2018 11:46, jim wrote:

If the serials are in use* Laplink used to use parallel ports?

https://en.m.wikipedia.org/wiki/LapLink_cable

The original laplink cable had both serial and parallel versions - they
did one with three connectors on each end - a DB25 male for parallel,
and DB25 & DB9 female for serial.

The parallel version did faster transfers (defaulting to a nyble wide
data path on a standard parallel port),

Really? IIRC (and I* may well not) it worked by twiddling the status
lines, because most parallel ports only had unidirectional data lines,
and was therefore slower.

While there were plenty of output lines available, there were only 5
available inputs (error, ack, paper empty, busy, & Select), so the
parallel cable cross wired those to give 4 data lines, and a strobe in
each direction.

God, I miss all that stuff not at all!

It was pretty cool at the time - you could transfer a whole directory of
files with between machines with incompatible sizes/densities of floppy
disk very easily.



I had some that used bidirectional parallel ports and they were much
faster than serial ports.

One of the cards I designed for System X used a serial port running at
880kbits/sec. That was pretty fast at transferring data to a tape drive.
IIRC the same chip was used in quite a few PCs to provide the serial
ports so they had the potential to run very fast.