AXE020 and AXE022
The AXE020 starter board is specifically designed to take the PICAXE28 series microcontrollers. All of these PICAXE28 series chips have the same pin-out for the primary inputs and outputs (see manual 1 page 26). Is just that some versions have added/different alternate functions for some of the pins.
The AXE022 is a prototype board which can take a PICAXE 28/40 series microcontrollers. There are no pull down resistors for the inputs or Darlington transistors for the outputs. You have a basic board with the microcontroller, programming socket and provision for external resonators. There is also provision for a PICAXE Net connection.
The pads are more intended for direct soldering of components or wires to them. There are 3 pads in series for each I/O pin on the PICAXE and then Vcc (+5V) and Vss (0V) tracks/rails each with a pad in line with the groups of 3 pads from each I/O. On my AXE022, the pad spacings are a bit variable.
For all I/O pins, the corresponding three pads are all at 0.1 inch spacing
Then at the outputs there is a 0.2 inch spacing to the Vcc and a further 0.1 inch to the Vss pads.
For the Analogue inputs and Port C pads the spacing between the group of three pads and the Vcc pads is slightly different so that connectors at 0.1 inch centres do not match.
The physically arrangement (conceptual, not to scale) of these pads is shown in my attachment on thread
http://www.picaxeforum.co.uk/showthread.php?t=9025&highlight=AXE022 at post No 4.
