Subject:
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RE: h8/300 16-bit multiply
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Newsgroups:
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lugnet.robotics.rcx
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Date:
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Mon, 4 Mar 2002 20:43:03 GMT
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Reply-To:
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<rhempel@(stopspam)bmts.com>
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Viewed:
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2931 times
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> Thanks. I have a version just 2 words longer that doesn't use the ROM
> code. Basically it's the ROM's code, trimmed down after assuming high
> words are zero initially. It's completely untested though, so there
> may be a bug.
<snipped code...>
Are you sure that it works for signed numbers :-)
> Yes, it's for my own Forth; given that it's for Mindstorms, reinventing
> the wheel is supposed to be half the fun.
If you like, I can give you some notes on how my Forth was developed.
I'm using a simple pseudo-assembler that lets me port this Forth
to a new processor in less than a day...
> By the way: in your code a "MOV.W #0x0000,r5" takes 4 bytes,
> whereas "SUB.W r5,r5" takes only 2 bytes.
Right you are. I may add this to my base in the future...
Cheers, Ralph
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Message is in Reply To:
 | | Re: h8/300 16-bit multiply
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| Thanks. I have a version just 2 words longer that doesn't use the ROM code. Basically it's the ROM's code, trimmed down after assuming high words are zero initially. It's completely untested though, so there may be a bug. CODE UM* \ 16x16=32 (...) (23 years ago, 4-Mar-02, to lugnet.robotics.rcx)
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