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Another gift idea: the HP85A


I have yet another idea for a self-gift: a working HP 85A computer



These were created more or less at the same time as the HP41c - maybe a year later. One of the first professional personal computers, it was the choice of engineers at the time. Its high price then (from 3500 USD and up, according to extras) took it out of the fight for volume, that was eventually won by the Apple II (the IBM PC would still take some time to appear in the market)


An interesting feature as a computer, is that it can perform calculations from the start up. In fact, it is a big calculator that can be programmed in HP Basic. There is no need to load an operating system - it was contained in the huge ROM (it had 48 kbytes ROM, to be compared with the 16 Kbytes the original PC had. At the time, the intelligence of a computer was measured by the size of its ROM. Now things have changed…) Any sentence including functions that was not preceded by a line number, was considered a command, interpreted, executed and its result displayed on screen. 

It had a CRT with 16 rows of 32 characters each, with a screen resolution of 256*192 pixels in a 4/3 format.

As I have ordered a new HP85, I can let go of the one I have. It has been professionally restored: the tape assembly has been changed by a brand new one, faster and more reliable, supplied by LA electronics; it can use both modern and old cartridges, and there is current offer of them; the pulleys of the printer have been changed and the assembly cleaned and tightened - a slight lack of contrast in a narrow band on the printout is the only tell-tale of its age; and the keyboard and screen work fine.


It comes with the ROM holder, with the advanced programming, printer/plotter and matrix ROMs, and there is also an HP-IB interface, to link it with other machines (the HP3478A multimeter and HP54510A Digital Oscilloscope that I have are examples). You can even create your own vintage lab, which can be programmed in easy BASIC, for very fast results and data analysis.

This is the computer model I learned to program with, back in 1980; but we threw that unit away 20 years ago. I have had a penchant for this model since, and finally I have not one but two units. 

It comes as well with a new tape and the Standard Pac tape too. The price has been lowered down to 699 €, VAT included (if you’re from out of the EU, you may save the VAT)

It comes with the manual - probably the best manual I have ever seen, much better than any other calculator manual. A real course on programming!




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