HARDWARE CONNECTIONS SP12 expects the AVR uC to be connected to the parallel port of your PC. Look at progrmmr.gif and icp_intr.gif for details. A plain cable as shown in those illustration often works, but adding Ken Huntington's `dongle' (dongle.gif) is recommended. It helps when the parallel port signal is marginal, and avoids the need for Sck termination cap and resistor as shown in the other illustrations. It also makes the cable high-Z except when sp12 is active, which can be very useful. And it is perfectly transparent to the software, except that you can't use the port control option (see sp12.txt). Sp12 can also adapt its use of the paralel port to the cable/dongles supplied with the Kanda STK200/300 starter kits. (See sp12rc.txt) NOTE: when using a dongle, your target board should have a reset circuit - at the very least a 10K resistor between the uC's reset pin and Vcc. WARNING: The `VCC' connection should only be made if the pcb containing the microcontroller has to use the parallel port as its power supply. This can be done safely if a supply current of less than 5 mA is sufficient, which is the case if you are using a `stand alone' programmer board with just a clock generator and a Zip socket for the microcontroller. SP12 will then automatically switch the supply current on and off as appropriate. This works with or without the `dongle' mentioned above, which is always powered by the parallel port. NOTE: The AVRCOM software found in previous SP12 packages has been replaced by the AVRmon package, which uses the programming lines Sck, Miso and Mosi. It offers interactive access to your AVR target hardware. You'll find it here: http://www.xs4all.nl/~sbolt/e-avrMon.html `STAND ALONE' PROGRAMMING PROCEDURE: The PC is switched on. Run SP12 -i to ensure that all parallel data bits are zero. Connect the programmer board to the parallel port. Use SP12 for whatever you wish to do, then switch off and disconnect the programmer board. The software is just as suitable for `in circuit' programming. In that case, the target board must allow free access to MOSI (PB5), MISO (PB6), SCK (PB7) and Reset. SCK must be terminated on the target board using a 22pf capacitor and a 100 ohms resistor, except when using the `dongle' mentioned above. On the reset pin, a 10K resistor and a 100N (100 nano-farad) capacitor may be used to make power-on reset more reliable. That combination allows SP12 sufficient access to Reset. Check icp_intr.gif for details. When using the `dongle', the minimum reset circuit is 10K between the uC's reset pin and Vcc. `IN CIRCUIT' PROGRAMMING PROCEDURE: The PC is switched on. Run SP12 -i to ensure that all parallel data bits are zero. Power up the target board (to between 3 and 5 volt). Connect it to the PC. Use SP12 for whatever you wish to do, then switch off and disconnect the target board.