chenmel at earthlink.net
Mon Nov 14 17:48:37 CST 2005
On Mon, 14 Nov 2005 13:33:01 -0600
Jim Battle <frustum at pacbell.net> wrote:
> woodelf wrote:
> > Having got a new PC ... 2 GHZ??? who knows the real speed.
> > I have tried Spare time gizmos - pdp 8 emulator ( A minor bug
> > -- with windows how do you get the bell to sound ?).
> > I was running some sort of diagnostics and had the RTC displayed
> > and for about 10 minutes of real time, the clock advanced a hour.
> > That must be at least 6x faster than the real thing on this computer.
> If a 2 GHz (give or take) x86 CPU emulates a pdp 8 at 6x, it means either the
> code is inefficient, or the code contains a speed regulator that doesn't work
> The original PDP-8 took 10 clocks at 1 MHz to execute one instruction, a 2 GHz
> CPU has 20 million cycles to interpret one instruction. So at 6x realtime, the
> program is using 3.2 million cycles to interpret one instruction.
Well, probably on said modern PeeCee, you could run eight or ten instances of the emulator without bogging the machine down. What degree of 'nice' (I know it doesn't exist in windoze, just wondering about the equivalent thing) does the emulator run at? The PC probably still has all the dancing, flashing foolishness that gatesware implies running in addition to the emulator.
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