6 ms·
> (Integer) Multiply/Divide. As I remember it, it had the instruction MUL, which did 8 by 8 bit unsigned multiply, but no divide. Maybe the Hitachi CMOS versi
by jonsen 6y ago
> (Integer) Multiply/Divide.
As I remember it, it had the instruction MUL, which did 8 by 8 bit unsigned multiply, but no divide.
Maybe the Hitachi CMOS version had it? I know this version had undocumented additional instructions.
EDIT: WP says it had hardware division:
https://en.m.wikipedia.org/wiki/Hitachi_6309 https://en.m.wikipedia.org/wiki/Hitachi_6309
- jacquesm 6y agoThat is exactly correct. You beat me by 60 seconds, while writing up my comment, I saw yours after posting. Interesting, I wonder how many neurons I'm wasting on useless 8 bit instruction set trivia.
- jonsen 6y agoSame here :), but a beauty like 6809 is worth remembering.
- jacquesm 6y agoYes, and it actually is one of the easiest sets to remember because there are so few exceptions. Everything that you expect to be there is there and works like you expect it to.
- DonHopkins 6y agoI always thought of the 6809 as the Chrysler Cordoba of 8 bit microprocessors, with soft Corinthian Leather upholstery and a luxurious automatic multiply instruction. https://www.youtube.com/watch?v=Vsg97bxuJnc https://www.youtube.com/watch?v=Vsg97bxuJnc "I have much more in this small CPU than great comfort at a most pleasant price. I have great confidence, for which there can be no price. In 6809, I have what I need."
- jacquesm 6y agoThe BS marketeers come up with never ceases to amaze me.
- ddingus 6y agoI just got one of these on a flash sale Color Computer upgrade kit. Should be fun to bang around on one of these days.
- HeyLaughingBoy 6y agoThen you need to know POKE 65495,0 :-)
- ddingus 6y agoIndeed. I just got a nice, old CRT for use with my retro machines. A CoCo upgrade and jam session is in my future.
- Zuider 6y agoIf I recall correctly, that instruction doubled the clock speed of the M6809, usually at the expense of making it go out of sync with the woeful 6847 video chip, putting colorful garbage on the screen.
- ddingus 6y agoWhen that happened, I think it was on the CoCo 1 and maybe 2. The three can do it with no worries. And the 3 didn't use the 6847, but a custom ASIC.
- HeyLaughingBoy 6y agoIt was OK on the CoCo2. ISTR doing it for some games I wrote in BASIC.
- ddingus 6y agoGood to know, LOL. We are so late on this chat. Fun stuff.