Odd Software for Odd Jobs


A fellow by the name of Steve very kindly gave me a Hewlett-Packard 86B "calculator" along with a neat little 9" green monochrome screen (82912A), three HP-IB cables and a ROM "drawer" (82936A) containing a few HP ROMs. I've since added an RS232 serial interface (82939A).

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I just love this little computer - the keyboard is awesome.

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The first thing I did was customise the LED, replacing the original amber LED with a 'modern' blue LED!

The computer comes with a built-in HP-IB (GP-IB, IEEE488) interface to which you would connect everything - disk drives, tape drives, plotters, instrumentation …

It also has four expansion ports into which I've got the ROM drawer and serial interface plugged in. You could also plug in other expansion boards, including a Z80 with its own 64kB of RAM so you could run CP/M software.

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The ROM drawer accepts HP-specific ROMs - Steve kindly gave me the I/O (00087-15003), plotter (00087-15002) and advanced programming (00087-15005) ROMs. There is an 82929A interface card that allows you to use your own programmed ROMs but as they are hard to come by someone has figured out the schematic.

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Its CPU is a HP custom chip codenamed Capricorn which runs at 625kHz! Considering that home computers of the same era typically ran at 4MHz this is a little … different. But the HP Series 80 computers were designed with a different purpose in mind.

I found a short fractal generation program and gave it a try - this fourth order Koch snowflake took about 1hr 46min to generate:

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Steve has also given me a massive HP 6942A multiprogrammer (that is for another post). I've got it hooked up to the 86B via the HP-IB and I've managed to poll it with the SPOLL command. My challenge for May is to get them talking to each other - an interesting exercise. Let's see how I go! Gotta learn about HP-Basic, HP-IB and the multiprogrammer!

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