[RC5] Porting to Atari?

Mike Silbersack silby at execpc.com
Sun Mar 22 00:22:33 EST 1998

On Sat, 21 Mar 1998 18:41:53 -0500, Alexander Li Cohen wrote:

>While everyone has been talking of porting to an Atari, I had an idea. What's wrong
>with the 286.  I've got one that I haven't turned on in almost a year, and I'm sure
>others are in the same situation.  Would it be even slightly feasible to make a port
>to these dinosaurs we all used to have(or still have, as door stops!)?
>Alex Cohen

A port to anything is feasible... but is it worth it?  A 386/12 gets 4373 keys/second running the DOS 32-bit client 
according to http://www.alde.com/speed.html.  Now, we're talking about running on a 286; the rc5 algorithm currently 
takes advantage of 32-bit registers fully, so we're talking AT LEAST 2x as many operations on a 16-bit processor.  So, 
we're down to 2100 keys/second... however, the 286 is also a slower 16-bit processor than the 386 is, so we're probably 
down to 1000 keys/second or less for a 286/12.  With 268435456 keys per block, that's 74 hours for a block.  My 
K6/200 can do the equivalent of that in 14 minutes or less.  In all reality, I have probably wasted more keys by writing this 
message than your 286 could do in a few hours.  The time it would take for our programmers to port the code to total 16-
bit code is definitely not worth it.

Mike "Silby" Silbersack
silby at execpc.com
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