11 Jun
2009
11 Jun
'09
8:53 a.m.
Jules Richardson wrote:
:)
Josh
Josh Dersch wrote:
It has an external power input, via some weird connector on the side.
It _does_ have a "high speed" mode -- if you turn it on while holding
"+" it runs 6 or 7 times faster (tested by running a program that just
runs a FOR loop from 0 to 1000 -- ~28 seconds in "normal" mode, ~4
seconds in "high speed" mode). No idea how it affects battery life, but
I can't imagine it's good :).
Internally though, they're 100% different --
the processor in the
MK-85 is a Russian PDP-11 knockoff. It's not a power-efficient CPU
by any means, so to ensure decent battery life the CPU speed is
severely limited. Not sure exactly what speed it runs at (anyone out
there know?) but the result is by far the slowest calculator I've
ever used.
That's interesting. Does it have provision for AC input? Just curious
if it auto-magically ups the clock speed when not running from the
battery, as that would be kinda cool (and an early example of a
power-saving mode :-) (The BASIC implementation is also incredibly
buggy, mostly due to
poor argument checking... see
http://www.pisi.com.pl/piotr433/mk85mc1e.htm for a cool example of
exploiting a bug in INPUT to do machine-language coding, in a way
only a contortionist could love...)
Gah, one of the home micro BASICs did something similar, so you could
throw MC in there as a character string and 'trick' the BASIC into
executing it by tripping the parser up - but my brain's refusing to
tell me which one it was now.
Anyone else know of examples of odd-duck machines
like this, where the
hardware is probably not the best choice for the application?
Anything ever done using an IBM-compatible PC?
(But it's cool anyway?)
Oh. Scratch that, then.
;-)