Benchmarking 3 floating point packages for the 6809

Software
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Sean Conner writes

I recently came across another floating point package for the 6809 (written by Lennart Benschop) and I wanted to see how it stacked up against IEEE-754 and BASIC floating point math. To do this, I wanted to add support to my 6809 assembler, but it required some work.

In excellent news, the newly discovered package is smaller and faster.

format cycles instructions
Microsoft 8752 2124
Lennart 7465 1326
IEEE-754 single 14204 2932
IEEE-754 double 31613 6865

(See also Moto’s floating point package for 6809 - in a ROM and perhaps A discussion of floating point)

via Two Stop Bits retro news aggregator

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try TSC floating point, Very fast.

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I found a listing - 42 pages but that’s more than just the core functions. Surprised to see it’s BCD (given that you say it’s fast!)
Technical Systems Consultants TSC Floating Point Package (42 page pdf)

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Topic caught my eye as interest in the 6809 and floating-point. It is great to see a comparison of software packages. 6809 is one of my favorites. Know of any hardware floating-point for the 6809?

Not exactly software, but one late night I added 128-bit decimal floating-point support to my rf6809 core written in System Verilog as register ‘G’. add, sub, mul, div, cmp, load and store. Divide takes something like 2000 cycles. However, the number of instructions used is really low as it is all “hardware”.

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The gcc6809 compiler supported/supports an external 68881 FP coprocessor, but how it’s connected is not clear. Let’s hope it’s more reliable than Innovative System’s FPE 68881 board for the Apple II from 1988. The only writeups I can find about that include more details about how often it crashes than the hardware itself.

If they were determined enough, and had a suitable power supply and cooling system, I’m sure someone tried to interface an Am9511 or Am9512 to a 6809 system.

Lastly, Micromega Corporation’s uM series of coprocessors were meant to be system-agnostic. While the website still exists, the product is unavailable as the company owner passed away a few years ago. I think the chips were based on PICs of some sort.

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