To choose is to renounce

this was the input I got very early on when I approached my hardware partner (Jean-Marc) about the possibility of building a kit on the basis of the Z79Forth prototype. The message is something one might hear in church but, in his mind, this took a particular meaning. It took me a while to realize the extent to which he was right, as a seasoned hardware designer himself.

At some particular point in time, I decided that it did not have to be so and I could have serial communications either on USB or on RS232. I made this a reality by the end of last year by resorting to a jumper based multiplexer. This was rewarding by itself and I remain proud of the result as an integrator. The additional required hardware is minimal:


  • a pair of 10 K resistors.
  • five 1 muF capacitors (ceramic un-polarized).
  • four dual-throw jumper based switches.
  • one Max 232 integrated circuit.
  • a ten pin Intel DTK compatible header.

Jean-Marc's opinion remains valid nonetheless. He also suggested the use of an off the shelf ATA/CompactFlash adapter that proved to be simpler than the original design was and more cost effective.

Recently I started specifying an extension connector. I ended up with 42 signals I wanted to make available for possible further hardware developments. One very important part of that signal set was the potential support for clock stretching, in order to accommodate slow (1 MHz) devices. Jean-Marc suggested a possible use of 8-bit SCSI cable assemblies (female-female, 2.54 mm pitch). Again. he was right on the money! The man is a blessing for the project.

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