The interface used with AccPlus and MemPlus utilities

Current version: 1.0 / updated 12/1/2007

  The Philips Standard Parallel Port Adapter works with our both utilities: AccPlus and MemPlus. It is very simple to make, uses a few cheap components and we help you as much as we can to get it work, via e-mail. The picture below shows you the adapter we have built, where you can see the connectors to SMBus, EEPROMs and parallel port, as well as the three sockets for the usual DIP memory packages. Its schematics can be found in the help files of the AccPlus or MemPlus utilities, and its PCB layout is available upon request.

  Observations

- The Philips interface has a few modifications, in order to work with both SMBus and serial memories. It is compatible with any version of the AccPlus and MemPlus utilities.

- The Data LED is added to show if SDA transfers are present;

- JP1 jumper is useful for the EEPROMs 29L394 or 93Cx6 to connect their pin 6 to Vcc. For 93Cx6 we recommend even pin 7 to be connected to Vcc (16 bits organization and write enable), see datasheets;

- The interface requires an external power source (+5V); USB or PS2 connectors can be used for this;

- The ON LED flashes three times if the interface is correctly detected;

- A parallel cable, 1:1, male-male, and shortest possible is required to connect the interface to the computer port;

- Pin 7 of the IC7405 must be connected to the GND, pin 14 to +VCC

- Your PC parallel port must be set in 'normal' or 'standard' mode.

- Do not connect any memory when the interface is powered!

   The Philips adapter can be easily manufactured, and requires one single integrated circuit 7405, nine resistors of 10k, one of 300ohms, a parallel DB25 male connector, two small LEDs, a 100nF capacitor and a few memory sockets.