Re: A89: An un-informed theory.


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Re: A89: An un-informed theory.




>    <snip>
>>ports.  This is possible on a moderately fast processor, but not on the
>>sluggish 10Mhz 68k (my 89 is really, really slow compared to my speedy
>>86...too bad my 86 won't do symbolic calculus).
>
>
>wow!  You think the 89 is slow compared to the 86?  Geez, i have an 86 as
>well, and I can't believe how much faster the 89 seems.  If you still think
>the 89 is slower, try graphing big plots and functions and you'll see the 89
>rules in speed.  I think that the 89 is actually 10mhz, whereas the 86 is
>something less (6?).  I'm not sure...
>
Yes, you are correct about the speeds (86 = 6Mhz, 89 = 10Mhz).  I wasn't
refering to graphs, I was refering to general calculations.  The 89 is much
slower overall, due to the rom being written in C and due to everything
being done symbolically.  But, you are right, I did notice graphing is much
faster.  I use my 86 for general math, and my 89 for checking symbolic math
(especially calculus). 

>>Emulation would be possible, but nowhere at full speed.  I'm no expert at
>>68k, but to my knowledge, the Z80 is much faster than a 68k (or an Intel
>>x86 for that matter) at the same clock speed.  I would guess that an
>>extremely efficient emulator would no faster than 1/5 (a guess!) of the
>>original calculator.
>
>this also doesn't make much sense....  I'm pretty sure that the clock speeds
>of the 68000 and the Z80 are relatively the same.  I know that the 68000 has
>a far superior instruction set as well as memory registers, but I doubt that
>the 8080's and Z80's are faster at the same clock speed...
>
Again, this was a guess.  But I know for a fact that the Z80 runs faster
than an equivalent Intel processor (8088) at the same clock speed.  I'll
check a cycle time chart sometime and find out for sure.

>I remember the old Macintosh computers used to use the same motorola chips
>as the 89 and the 92 do now (although they used the 68020,030, and 040
>instead).
>
>oh yes, one more thing:  why would you even want to emulate another
>calculator?  Aren't all the games that are ported from say the 85 to the 92
>better anyway?  Why would you want to slow down your calc, AND play
>less-advanced games?
>
Beats me!  The games for the 92 are much better than any 85/86 games (82/83
are  almost always clones/ports of 85/86 gameS).  Even though a few 86
games would be cool to rewrite to the 89.  But I think they were refering
to emulating the entire calculator to use it's math capabilities.  Again, why?

Another note, when talking about converting games between the 86 and 92 (or
any Z80 vs. 68000 calc), the correct term is REWRITE, not PORT.  Porting
implies using most of the original code, while changing the platform
dependant portions.  But when you have a different processor (when talking
about assembly) the entire program must be rewritten.  This is why C/C++ is
used much more often for game development (PC's/Consoles, not calcs!),
because games don't have to be completely rewritten for the new platform
(i.e PC -> Playstation).  But I'm getting off topic, so I'll end it right
here...

--
David Phillips
mailto:electrum@tfs.net
ICQ: 13811951
AOL/AIM: Electrum32