pen plotters?

There are a fair number of manuals (user, service, programming, etc) for HP pen plotters ( over on http://www.hpmuseum.net/ . A few HP Plotters (7470, 7475, Colourpro, etc). Probably the oddest one I have is the HP7470 Opt 003. It has an HPIL interface and can be driven 'Plotter ROM' module for that calculator. A few of thost 'Alps 4 pen printers' You know, the mechanism that was used by just about everyone in the early 1980s. Tandy CGP115, Commodor 1520, Oric printer, Sharp made several (including the 'printer' for the PC1500 pocket computer)m, etc. An Epson thing that I forget the number of (perhaps somebody can identify it form the description, and suggest a source of docuemtnation). It plots on A4 sheets, rolling the paper back and forth for one axis and moving the pen carriage accorss for the other. The carriage holds 4 pens in a straight line across the paper, and by running it into stops at the ends of the printer, the pens assembly is shfited relative to the carriage, moving a different pen into the 'active' postion. The model number is something like 'HI-80' I think. A Tektronix 4662 (flatbed, single pen), HPIB and RS232 interfaces. Incidentally, a friend is looking for any service information of the multi-pen option for this unit (the service manual I have for the machine only covers the single-pen model). I don't know if you count them but I have a couple of analogue flatbed X-Y recorders, with valved electronics. IIRC one is made by Houston Instruments, the other by Bryans The thing I am looking for (in the UK for obvious reasons) is an HP9862 plotter with 9800-series interface module. Little chance of getting one, though. -tony