# Parallel to Parallel cable + additional serial



## mk (Jan 3, 2011)

I have two machines that want to connect. The cable that I have at the moment is parallel to parallel male-female where it have additional 9 pin serial male port. On machine A there is already parallel port but no serial (extension port but no extension card) while on machine B there is serial+parallel extension card. Can I and how to use this cable? Machine A gets parallel plug and machine B takes serial plug or parallel to parallel? Now if I use pure serial-serial I can use *cu* to connect, but what to use for parallel to parallel (if that is what I have to use)
I can't provide picture of my cable. 
Please advise.


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## SirDice (Jan 3, 2011)

mk said:
			
		

> The cable that I have at the moment is parallel to parallel male-female where it have additional 9 pin serial male port.


Do not confuse a 25 pin serial connector with the 25 pin printer (parallel) connector. Only the serial connector is also available as a 9 pin and there are converters for 25 pin -> 9 pin serial.  



> Now if I use pure serial-serial I can use *cu* to connect, but what to use for parallel to parallel (if that is what I have to use)



There is no standard for connecting 2 parallel ports and communicating over them. At least not between 2 computers. There were several solutions but they all used their own implementation and needed specific software. Serial -> serial is a standard (RS-232).


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## mk (Jan 3, 2011)

If that will be the case, perhaps usb to serial would do the job? Or there is other complications?


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## SirDice (Jan 3, 2011)

USB to serial should work. I have one that works fine.


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## aragon (Jan 3, 2011)

If you can find the right parallel cable... lp(4).

(man page has the pinouts if you're up to making your own)


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## wblock@ (Jan 4, 2011)

aragon said:
			
		

> If you can find the right parallel cable... lp(4).
> 
> (man page has the pinouts if you're up to making your own)



Can't imagine a situation where that would be practical, but I must admit to a morbid curiosity about what kind of transfer rate it achieves.  (Actually tried parallel to parallel networking years ago, and it wasn't quick or reliable.  Parallel ports are kind of eletrically fragile, too.)

There were USB "networking" cables also (Laplink), some kind of host-to-host adapter I've never encountered in the wild.  Was there ever a FreeBSD driver for those?

These types of networking are good at showing how great Ethernet really is.


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## aragon (Jan 4, 2011)

wblock said:
			
		

> Can't imagine a situation where that would be practical, but I must admit to a morbid curiosity about what kind of transfer rate it achieves.


I used to do basic networking with parallel ports years ago, and also owned a parallel Zip drive at one stage (actually, it's packed in a box in the garage).  They perform really well if ECP/EPP mode is available.  Better than 10 Mbit ethernet, which was a lot back then.


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## mdhughes (Jan 4, 2011)

Do a man on plip


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