x86/DOS system backup via rs232?

[Chuck Guzis]

On 11/14/2015 07:52 AM, Jules Richardson wrote:
> On 11/13/2015 11:56 PM, Chuck Guzis wrote:
>> connected them with a Laplink parallel cable (I've still got a box of
>> them).
>
> Roughly what length are the cables? And do you know if they do anything
> special internally regarding shielding of the data lines?

For my own product, way back in the dark old days, I designed one from 
scratch and contracted for a couple hundred from a cable house.  When 
Laplink came out, I was surprised to find that it used exactly my setup. 
  How's that for coincidence?

So I changed my further orders to use the commodity LL cables--at about 
half the price.  Not as rugged as my design, but they worked fine. 
Interlink uses the same cable.

All were 2m in length. I think 12 conductor commodity foil-shielded 
cable will do the trick.  Basically, you've got 4 data lines in each 
direction, plus strobe and ground.  It is possible (I don't know if 
Interlink supports it) with PS/2 style bidirectional printer ports, to 
do a full 8 bit transfer in both directions, but it can get touchy on 
setup.  The 4-bit cables nearly always work.

So a length of cable, 2 DB25M connectors and Bob's your uncle.

https://support.microsoft.com/en-us/kb/142324

MIcrosoft calls/called it "Direct Cable Connection" and is supported 
through Windows XP (Vista dropped it).

--Chuck