Dumb Mouse

Newsflash: Our newly found company N₂IT will sell the Dumb Mouse kits soon! See http://www.n2it.net/ for more details.

1.1. Introduction

The Dumb Mouse was developed to give hobbyists a simple device to experiment with new smart card technology. The Dumb Mouse can read all ISO 7816-3 compatible smart cards and probably most other types, including memory cards.

Jumper settings are provided to allow compatibility with other types of cards and to work with most available software (after applying our "patches": see below).

The Dumb Mouse is easy to build and it should not be too big of a problem to get the parts. If you build it yourself, it will cost about 25 guilders. If interest is high enough, a few kits will be made available some time later at a slightly higher price. We will then publish details on this page.

We do NOT sell assembled Dumb Mice (we don't sell anything yet), if you cannot build it yourself, find somebody who wants to do this for you.

1.2. Technical Specifications

Serial port used for communications.
Power is supplied from the serial port or externally.
Vpp can be provided if necessary.
3.58 MHz internal clock, external or software clocking possible.
Card reset can be active high or low.

1.3. Building the Dumb Mouse

The Dumb Mouse is very easy to build for somebody who has ever hand wired a circuit. It is virtually impossible to do any damage to any of the components, the serial port or the chipcard.

The schematic appeared in the second issue of Klaphek. Information on back issues is available on their homepage.

Although buying an issue of Klaphek is the best solution (nice paper magazine with more informing articles), the Dumb Mouse schematics and building instructions have been put into digital form by Eric Blossom (eb@cypherpunks.to) and are online at ftp://cuba.xs4all.nl/cards/hardware/ in tar.gz and zip format.

Allthough we have verified the schematics to be correct, we have not looked at them very thoroughly (parts list etc.), and therefore any questions about it should go to the authors of these schematics. Every reference to the schematic below applies to the original schematic as it appeared in Klaphek. Recently, the Dumb Mouse schematics are also available from the klaphek web page, at http://www.klaphek.nl/files/dumbmouse.zip.

Note however that these are available for non-commercial purposes only. If you are interested in using the Dumb Mouse in a product, it is best to contact the designers at hip@cuba.xs4all.nl.

Most important is to get a "landing contact" chip socket. Cheap "sliding contact" or "scratching contact" chip sockets will wear out your card very soon. Landing contact sockets start at 16 guilders.

Everything can be built on a circuit board the size of a chipcard. Some may prefer to make it slightly larger, for easier assembly.

Before building you might want to apply a few changes to the schematic (see below). It is adviced to do this, because then your dumbmouse will work with the available software.

Also, the circuitry surrounded by dashes is for applying Vpp, which is rarely used and may be omitted.

1.4. Changes

A few changes were made to the schematic to facilitate the use of more software. They are optional.

1.4.1. Output on RI (or RNG)

This is to greatly simplify the software for reading memory cards.

To do it: connect pin 2 to pin 9 (RI or RNG) on the D9 serial connector.

1.4.2. Suppress local echo

This can make programming easier and allows some existing commercial software to be used. In fact, with echo suppressed the message format for smart cards is according to ISO 7816-3.

To do it: Free pin 13 of U1F. Insert a 10k to 47k resistor. Connect the cathode (stripe) of a small diode (e.g. 1N4148) to pin 13 of U1F. The other side has to be connected to TxD (pin 3) of the D9.

If you like you can make this change jumper configurable.

1.5. Troubleshooting

Some older models of IBM computers and one model of Commodore Amiga and computers with RS422 ports (like some Macs) will not work with the Dumb Mouse. If you happen to have such a computer, we can supply additional information to get the Dumb Mouse working.

1.6. Software for the Dumb Mouse

Writing the software for the Dumb Mouse should not be too hard if you know how to control the serial port and can follow the schematics. There is enough documentation available on the Net about how to program a serial port under whatever operating system you use.

SCAM is a program written by us, partly in C++ and partly in Perl. Currently it has only been tested on Linux, but it should work on any Unix system. You should set the jumpers to active reset low on your Dumb Mouse if you use this software.

There are several other programs written by us, although these are still in an experimental stage. These may be put online later.

We would like to know of any other software products that are "Dumb Mouse compatible" and especially those that are developed by hobbyists.

You can take a look at the SOFTWARE page as well, to find information about other software.

1.7. Feedback and Comments

Any comments on the above can be mailed to hip@cuba.xs4all.nl