HP 7475A Plotter Interface

HP 7475A Plotter 2 HP 7475A Plotter 1

In the early 80s I always wanted to get a plotter. But they were far too expensive. So the only option was to build one myself with fischertechnik . The results were not nearly as good as a professional plotter. Now 30 Years later I suddenly remembered that I always wanted to get a high quality plotter. And so I bought a Hewlett-Packard 7475A on a known auction platform. It works, draws highly precise images (the spec says 0.025 mm accuracy) and even today you get pens for it.

USB to RS-232 Adapter

FTDI232DSUB25 Board FTDI232DSUB25 Schematics

The HP 7475A is available with to interface types HP-IB (IEEE 488) and RS-232. Mine has a RS-232 (D-Sub DB25 female), so I needed a USB to serial converter cable. If you’re a fan of soldering very small SMD parts (the FTDI232 chip is not the easiest one to work with), you can use this Eagle files to produce your own connector cable.

FTDI 232 D-Sub 25 shield Eagle files (board + schematic)