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| I was very lucky to obtain this A4 plotter from eBay in June
2018. It was advertised as untested and came without its mains plug,
software, manual, magnetic strips or pen and it needed a very good
clean.
Opening the plotter revealed two circuit boards. One was a simple, regulated power supply, which tested OK, and the other contained drivers for the stepper motors which moved the plotter arm and pen. The plotter was very clean inside. The guides for the arm and pen had phosphor-bronze oiled bearings. These bearings normally do not need lubricating but over the last 30 years or so they had dried out and needed a touch of high grade lubricating oil. After reassembling the plotter was powered up. The arm and pen gave a slight twitch confirming power was reaching the stepper motors. The next job was to see if there was any software available on the internet. A quick search found the driver disc for the Plotmate A4M. The basic Plotmate drivers were on the disc and were transferred to my Master computer and used to test if the plotter worked. In addition a copy of the Plotmate manual plus some useful information about where to obtain pens was discovered. The original pens are sadly obsolete but an equivalent version 1CY14P5-N can still be obtained although it was no longer a stock item and was supplied in packs of 5. The Plotmate drivers showed that the plotter worked outstandingly and that there was no hysteresis or play on the motors, belts or gears. Not bad after 30+ years! The ROM found on the Internet was for the A3M version and would not work with the A4 version so the search was on for an A4 ROM. Luckily a request on the StarDot forum produced the goods when a member remembered that a computer they purchased had a Plotmate A4 ROM in it and that they had imaged it. The missing magnetic strips were sourced from Amazon. They were part of a long roll of magnetic tape intended for making table lines on a magnetic whiteboard. Finally I had a plotter that worked. The original system disk is still missing but the present system works well. Later a copy of the Welcome disc was discovered and this is in the main Archive. Turning my attention to the manual I decided to re-typeset it. The download was OK but could be improved and contained several typographic errors. It also did not contain any reference to the ROM. After a couple of days of effort and another to add the ROM details, the manual had been restored. A replacement system disc was produced and this also contains the ROM image. The whole package of software, including the ROM image, manual and pen details can be downloaded here. Since then another copy of the Plotmate A4 documentation has come to light. The various sections are listed below. Parts of the documentation were in a sorry state; the ink had become plastic over time and had stuck to the opposing pages. Much time was taken to remove blemishes from the scans to restore the documentation to close to its original condition. The ROM fitting instructions, however, were too far gone and had to be re-typed before posting. Original Plotmate A4 User manual Original ROM version instructions Original LOGO users guide Original Hershey characters instructions - for the Beebug Hershey Characters software Re-typed ROM fitting instructions |
