The inexpensive MCR-8 (or MCR-7) magnetic card reader from All Electronics is supplied with a 22-inch cable terminated in a 6-pin RJ-11 plug. Using a RJ-11 to DB-25 adapter kit, it's easy to connect one of these readers to a parallel port for use with StripeSnoop without having to do any soldering.
Software considerations: I was unable to make the MCR-8 reader work without using pin 2 of the parallel port to power the reader. StripeSnoop 1.6 ALPHA has no provision for actuating this pin and additional software is required. For Linux, I use the free program PPORT (http://sourceforge.net/projects/pport/). PPORT version 0.6.9 or greater is required for I/O port addresses greater than 0x3FF. Presumably a similar program exists for Windows.
Warning:
A parallel port can be easily damaged by the wrong pin connections or if too much current is drawn from the pins. The current drawn by the MCR-8 from pin 2 with the circuit described below is about 2.1 mA quiescent rising to about 2.5 mA when a card is being swiped. The old IBM PC-XT manual says that the pin can supply 2.6 mA, so this circuit _ought_ to be safe, but be warned that you may risk smoking your motherboard port. I recommend using a parallel port add-on card for projects like this, and picked up a no-name PCI add-on card for $18 at a local computer shop.
Hardware:
Here's the link to the MCR-8 card reader ($1.50):
<http://www.allelectronics.com/cgi-bin/category.cgi?category=367&item=MCR-8&type=store>
Here is a link for the RJ-11 to DB-25 adapter I used:
<http://www.pigselectronics.com/products/HOOD.htm> (HOOD $0.50)
Alternate adapter kit source (has good pictures!):
<http://store.a2zcable.com/ty16.html> (DB25-M to RJ11-F/RJ12-F(6C) $2.95)
<http://store.a2zcable.com/ty27.html> (DB25-M to Keyed RJ45-F (8C) $2.95)
Adapter notes:
The RJ-11 jack on the adapter from PIGS Electronics will accept a RJ-45 plug as well as a RJ-11 plug. This makes it possible to use a standard RJ-45 Ethernet cable and RJ-45 inline connector to extend the relatively short cable on the MCR-8 reader if necessary. The Part TY27 adapter kit from A2Z Cables has the same advantage but has 8 wires, the inner 6 of which are used for this project.
(The AD-14 adapter listed in the All Electronics catalog is unfortunately NOT compatible - its RJ-11 jack requires a plug with an offset prong.)
Given the shipping charges for online purchases, you may want to consider purchasing more than one adapter, just in case, for two reasons:
1. If you mistakenly wire one up wrong and don't have an extraction tool to remove the pins, you're sunk.
2. You'll notice the circuit described below omits a jumper between two pins required by Acidus' Omron parallel port adapter. If a jumper should be required in the future, an adapter can be sacrificed to get two wires with attached pins which can be twisted together to make the jumper.
Construction:
The 6-pin RJ-11 plug on the MCR-8 card reader comes wired like this, looking at the plug from the end with the prong down:
Shield(N/C), Black(ground), Red(5v), Green(clock), White(C.P.), Brown(data).
It's critical to match the wires in the adapter's jack to the corresponding pins on the MCR-8's plug - you can't necessarily go by the colors. Look at the wires emerging from the back of the RJ-11 (or RJ-45) jack in the adapter, held with the prong side down. They're staggered in two rows. I've noted below the wire colors in the adapter from PIGS Electronics I used, but fill in the adapter wire colors for whichever adapter you have in the following table:
MCR-8 Color/ Adapter Wire color DB-25 Pin number
Function (PIGS color)
Extra (RJ-45) (N/A) _________ N/C (*)
Shield(N/C) (White) _________ N/C
Black(ground) (Black) _________ 25
Red(5v) (Red) _________ 2
Green(clock) (Green) _________ 12
White(C.P) (Yellow) _________ N/C (**)
Brown(data) (Blue) _________ 13
Extra (RJ-45) (N/A) _________ N/C (*)
(*) Only for adapters like the A2Z Cables TY27 with 8 wires.
(**) The Card Present (C.P.) line is unused in StripeSnoop 1.6 Alpha. Leave it disconnected for now.
Having identified the adapter wires, their pins can be pushed into the holes in the DB-25 connector body. The pin numbers are molded into the connector body - you may need a magnifying glass to read them. Insert the pins into the proper holes and push on the back of each pin with a piece of stiff wire, like a paper clip, until it snaps into place. (Don't be tempted to _pull_ the pins into place from the other side with pliers - they're hollow and easily crushed.) Make sure to insert the pins into the correct holes the first time - they're impossible to remove without an extraction tool once they've snapped into place.
Use pieces of black electrical to wrap the pins on the unconnected wires so they won't short out anything.
Double check your work, then tuck the wires into the shell of the adapter and snap the connector body into place.
We're done! Plug the MCR-8 reader into the adapter and the adapter into the parallel port of your PC.
Operation:
You MUST determine the I/O Port address for your particular parallel port. The usual base address for PC motherboard parallel ports is 0x378, but if like me you're using an parallel port add-on card to avoid risking your motherboard the port address will be different. ISA add-on cards will usually be 0x278. PCI "Plug 'N' Pray" cards may be anything - in my case it is 0x9800. Linux users can run 'cat /proc/ioports' or '/sbin/lspci -v' for this information. Windows users can check the port propeties in Device Manager.
The Linux PPORT program I mentioned above must be compiled with a specific port address in mind. In my case, after unpacking the source code I ran:
$ ./configure --with-parport=0x9800
$ make
$ su
# make install
PPORT or an equivalent program uses the base address of the port. So with PPORT configured as above, I actuate pin 2 with:
# pport -s 2
StripSnoop 1.6 ALPHA uses the base address + 1. So I run StripeSnoop with:
# ss -P 0x9801
Optional purchases: Here are some other items also available from A2ZCables:
DB Pin Insertion/Extraction tool (part LINS1 $4.95)
RJ-12 to RJ-12 inline coupler (part TY28S $2.95)
RJ-12 to RJ-12 6-conductor, 7 foot cable (part T66S-7 $4.95)
The tool is essential if you're planning to do very much fiddling with crimp-type DB connectors or adapters. The (6-conductor) inline coupler and 7 foot cable is handy if the 22 inch cable connected to the MCR-8 reader is too short for convenient use of the reader with your PC. Note: All Electronics (where you buy the card reader) also lists 6-conductor RJ-11 cables - less expensive, but they've been back-ordered on the 7-foot length (CAT# MT-363 $1.25) for a long time.
Regards,
Charles Sullivan
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
The inexpensive MCR-8 (or MCR-7) magnetic card reader from All Electronics is supplied with a 22-inch cable terminated in a 6-pin RJ-11 plug. Using a RJ-11 to DB-25 adapter kit, it's easy to connect one of these readers to a parallel port for use with StripeSnoop without having to do any soldering.
Software considerations: I was unable to make the MCR-8 reader work without using pin 2 of the parallel port to power the reader. StripeSnoop 1.6 ALPHA has no provision for actuating this pin and additional software is required. For Linux, I use the free program PPORT (http://sourceforge.net/projects/pport/). PPORT version 0.6.9 or greater is required for I/O port addresses greater than 0x3FF. Presumably a similar program exists for Windows.
Warning:
A parallel port can be easily damaged by the wrong pin connections or if too much current is drawn from the pins. The current drawn by the MCR-8 from pin 2 with the circuit described below is about 2.1 mA quiescent rising to about 2.5 mA when a card is being swiped. The old IBM PC-XT manual says that the pin can supply 2.6 mA, so this circuit _ought_ to be safe, but be warned that you may risk smoking your motherboard port. I recommend using a parallel port add-on card for projects like this, and picked up a no-name PCI add-on card for $18 at a local computer shop.
Hardware:
Here's the link to the MCR-8 card reader ($1.50):
<http://www.allelectronics.com/cgi-bin/category.cgi?category=367&item=MCR-8&type=store>
Here is a link for the RJ-11 to DB-25 adapter I used:
<http://www.pigselectronics.com/products/HOOD.htm> (HOOD $0.50)
Alternate adapter kit source (has good pictures!):
<http://store.a2zcable.com/ty16.html> (DB25-M to RJ11-F/RJ12-F(6C) $2.95)
<http://store.a2zcable.com/ty27.html> (DB25-M to Keyed RJ45-F (8C) $2.95)
Adapter notes:
The RJ-11 jack on the adapter from PIGS Electronics will accept a RJ-45 plug as well as a RJ-11 plug. This makes it possible to use a standard RJ-45 Ethernet cable and RJ-45 inline connector to extend the relatively short cable on the MCR-8 reader if necessary. The Part TY27 adapter kit from A2Z Cables has the same advantage but has 8 wires, the inner 6 of which are used for this project.
(The AD-14 adapter listed in the All Electronics catalog is unfortunately NOT compatible - its RJ-11 jack requires a plug with an offset prong.)
Given the shipping charges for online purchases, you may want to consider purchasing more than one adapter, just in case, for two reasons:
1. If you mistakenly wire one up wrong and don't have an extraction tool to remove the pins, you're sunk.
2. You'll notice the circuit described below omits a jumper between two pins required by Acidus' Omron parallel port adapter. If a jumper should be required in the future, an adapter can be sacrificed to get two wires with attached pins which can be twisted together to make the jumper.
Construction:
The 6-pin RJ-11 plug on the MCR-8 card reader comes wired like this, looking at the plug from the end with the prong down:
Shield(N/C), Black(ground), Red(5v), Green(clock), White(C.P.), Brown(data).
It's critical to match the wires in the adapter's jack to the corresponding pins on the MCR-8's plug - you can't necessarily go by the colors. Look at the wires emerging from the back of the RJ-11 (or RJ-45) jack in the adapter, held with the prong side down. They're staggered in two rows. I've noted below the wire colors in the adapter from PIGS Electronics I used, but fill in the adapter wire colors for whichever adapter you have in the following table:
MCR-8 Color/ Adapter Wire color DB-25 Pin number
Function (PIGS color)
Extra (RJ-45) (N/A) _________ N/C (*)
Shield(N/C) (White) _________ N/C
Black(ground) (Black) _________ 25
Red(5v) (Red) _________ 2
Green(clock) (Green) _________ 12
White(C.P) (Yellow) _________ N/C (**)
Brown(data) (Blue) _________ 13
Extra (RJ-45) (N/A) _________ N/C (*)
(*) Only for adapters like the A2Z Cables TY27 with 8 wires.
(**) The Card Present (C.P.) line is unused in StripeSnoop 1.6 Alpha. Leave it disconnected for now.
Having identified the adapter wires, their pins can be pushed into the holes in the DB-25 connector body. The pin numbers are molded into the connector body - you may need a magnifying glass to read them. Insert the pins into the proper holes and push on the back of each pin with a piece of stiff wire, like a paper clip, until it snaps into place. (Don't be tempted to _pull_ the pins into place from the other side with pliers - they're hollow and easily crushed.) Make sure to insert the pins into the correct holes the first time - they're impossible to remove without an extraction tool once they've snapped into place.
Use pieces of black electrical to wrap the pins on the unconnected wires so they won't short out anything.
Double check your work, then tuck the wires into the shell of the adapter and snap the connector body into place.
We're done! Plug the MCR-8 reader into the adapter and the adapter into the parallel port of your PC.
Operation:
You MUST determine the I/O Port address for your particular parallel port. The usual base address for PC motherboard parallel ports is 0x378, but if like me you're using an parallel port add-on card to avoid risking your motherboard the port address will be different. ISA add-on cards will usually be 0x278. PCI "Plug 'N' Pray" cards may be anything - in my case it is 0x9800. Linux users can run 'cat /proc/ioports' or '/sbin/lspci -v' for this information. Windows users can check the port propeties in Device Manager.
The Linux PPORT program I mentioned above must be compiled with a specific port address in mind. In my case, after unpacking the source code I ran:
$ ./configure --with-parport=0x9800
$ make
$ su
# make install
PPORT or an equivalent program uses the base address of the port. So with PPORT configured as above, I actuate pin 2 with:
# pport -s 2
StripSnoop 1.6 ALPHA uses the base address + 1. So I run StripeSnoop with:
# ss -P 0x9801
Optional purchases: Here are some other items also available from A2ZCables:
DB Pin Insertion/Extraction tool (part LINS1 $4.95)
RJ-12 to RJ-12 inline coupler (part TY28S $2.95)
RJ-12 to RJ-12 6-conductor, 7 foot cable (part T66S-7 $4.95)
The tool is essential if you're planning to do very much fiddling with crimp-type DB connectors or adapters. The (6-conductor) inline coupler and 7 foot cable is handy if the 22 inch cable connected to the MCR-8 reader is too short for convenient use of the reader with your PC. Note: All Electronics (where you buy the card reader) also lists 6-conductor RJ-11 cables - less expensive, but they've been back-ordered on the 7-foot length (CAT# MT-363 $1.25) for a long time.
Regards,
Charles Sullivan