September 15, 1995



BASIC Stamp I Pin-Out:

    Pin      Name                 Function
    --------------------------------------------------------------------------
      1      PWR                  Accepts 6-15 VDC power supply input.  Use
                                  only if no voltage is applied to +5V pin.

      2      GND                  System ground.  Connects to PC parallel port
                                  pin 25 (GND) for programming.

      3      PCO                  PC Out.  Connects to PC parallel port pin 11
                                  (BUSY) for programming.

      4      PCI                  PC In.  Connects to PC parallel port pin 2
                                  (D0) for programming.

      5      +5V                  5-volt input/output.  If a higher voltage is
                                  applied to the PWR pin, then this pin will
                                  output 5 volts.  If no voltage is applied to
                                  the PWR pin, then a regulated voltage
                                  between 4.5V and 5.5V should be applied to
                                  this pin.

      6      RES                  Reset input/output.  Goes low when power
                                  supply is less than 4 volts, causing the
                                  Stamp to reset.  Can be driven low to force
                                  a reset.

      7-14   I/O pins             General-purpose I/O pins.  Each can sink
                                  25 mA and source 20 mA.  However, the total
                                  of all pins should not exceed 50 mA (sink)
                                  and 40 mA (source).



BASIC Stamp II Pin-Out:

    Pin      Name                 Function
    --------------------------------------------------------------------------
      1      TX                   Serial output.  Connects to PC serial port
                                  pin 2 (RX) for programming.  May also be
                                  used by user's program.

      2      RX                   Serial input.  Connects to PC serial port
                                  pin 3 (TX) for programming.  May also be
                                  used by user's program.

      3      ATN                  Serial attention line.  Connects to PC
                                  serial port pin 4 (DTR) for programming.

      4      GND                  Serial ground.  Connects to PC serial port
                                  pin 5 (GND) for programming.

      5-20   I/O pins             General-purpose I/O pins.  Each can sink
                                  25 mA and source 20 mA.  Pins 5-12 and
                                  13-20, as groups, can each sink 50 mA and
                                  source 40 mA.

      21     +5V                  5-volt input/output.  If a higher voltage is
                                  applied to the PWR pin, then this pin will
                                  output 5 volts.  If no voltage is applied to
                                  the PWR pin, then a regulated voltage
                                  between 4.5V and 5.5V should be applied to
                                  this pin.

      22     RES                  Reset input/output.  Pull low to reset; goes
                                  low during reset.

      23     GND                  System ground connection.

      24     PWR                  Accepts 6-15 VDC power supply input.  Use
                                  only if no voltage is applied to +5V pin.


Stamp II note:  for the Stamp II software to automatically locate the Stamp II
on any serial port, you must connect DSR (DB9 pin 6) to RTS (DB9 pin 7) on
your PC's serial port.  Otherwise, you will receive a "Hardware not Found"
error.  If this is a problem, you can tell the software which port to try by
using the command-line option as follows:

    STAMP2 /x

Where "x" is the serial port number (1-3).

Please note that the Stamp II Carrier Board makes the DSR-to-RTS connection, so
this error should not occur if the carrier board is being used.
