Those Disappearing Parallel Ports

You probably know that it is just about impossible to buy a new laptop computer with a parallel port these days.  This is sad news for those of us who have been attaching custom hardware devices to these ports since the first IBM PCs were produced in the 80's. Two widely used designs that depended on this port are the MAX186 and MAX187 ADCs promoted on this website.  This page discusses possible solutions for users of these circuits.


While the parallel port is also disappearing from desktop computers, it is still possible to purchase an inexpensive PCI card that provides you with one.  These will work fine with the latest versions of Radio-SkyPipe. If the card maps to one of the old standard I/O port addresses, ( 278H, 378H, and 3BCH ) you will also be able to use older Radio-SkyPipe I versions with these cards.  Radio-SkyPipe II allows you to select a non-standard I/O port address and so it will work with parallel cards that demand this. You may currently find these cards for about $10 on eBay. 


The biggest problem has been felt by users of new laptop computers.  Here the solution is not so simple.  The parallel port has been almost universally replaced by the USB port.  Serial port users have had no problem because USB to Serial converters are cheap and plentiful.  These devices serve as direct replacements for computer serial ports and there is no issue with using them with custom software aimed at controlling external devices through a standard Com Port.  USB to Parallel converters are available but they do not work with software that tries to directly access computer I/O ports. (There is one exception discussed below. *) Instead these converters present a different type of interface, one that is fine for old printers but does not give access to the individual pins for custom uses.  Very disappointing, but there may be another option.

PCMCIA and ExpressCard

Does your laptop have a PCMCIA (CardBus) slot? If so, you may try a PCMCIA to Parallel adapter.  I have not tried one yet, but the language on the eBay listings for these seems to infer that they would work. One seller makes these claims:

Seems like it should work.  If anyone tries one of these please let me know the results so we share with others.

The PCMCIA CardBus standard is old and new laptops more frequently have  ExpressCard  slots.  The chatter is that these adapter cards will work, but I do not have a laptop with an ExpressCard to experiment with.  You may have to install the "paraport.sys" driver from Microsoft if the PC does not have this already. A non-standard I/O port address is likely but you should be able to find out the address in Device Manager.  The possibility exists that only some Express Cards may work, so please forward to me what result you have with your particular model.

A USB option

*Another option is an open source USB to Parallel device available from a seller in Germany.  He provides everything you need to build your own from scratch including board layouts.  See his website.  It appears that he does not always have them for sale but sometimes does.  He requests that you email him for orders.  There should be a large demand for these and I do not understand why someone isn't capitalizing on this. 

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