Ethan,
Are you really at the south pole?
Can I come and visit?
Steve.
--- Ethan Dicks <dickset_at_amanda.spole.gov> wrote:
> On Sun, Jan 25, 2004 at 05:46:54PM -0800, steven
> wrote:
> > My first attempt at the so-called killer poke on
> my
> > Commodore PET 2001-8 resulted in a 30% speed
> increase!
> >
> > I used "POKE 59458,62"
> >
> > No smoke, either!
>
> That's because it's a 2001-8. The old, TTL video
> PETs used that POKE
> to, in effect, let BASIC "ignore" the vertical
> blanking interrupt. In
> essence, the ROM routing for PRINT checks the VBI
> and only fiddles with
> video memory when the beam is off. That's why
> directly manipulating
> screen memory in machine language was always faster.
>
> The problem came with _later_ models than yours.
> IIRC, the effect of
> the "killer poke" was to change the direction of a
> bit in a PIA or VIA
> from an input bit to an output bit. The consequence
> of that is, with
> one of the later models with a different video
> circuit, a totem-pole
> transistor arrangement was permanently engaged and
> one of the transistors
> was overdriven and smoked.
>
> -ethan
>
> --
> Ethan Dicks, A-130-S Current South Pole Weather
> at 26-Jan-2004 08:20 Z
> South Pole Station
> PSC 468 Box 400 Temp -19.5 F (-28.6 C)
> Windchill -45.5 F (-43.1 C)
> APO AP 96598 Wind 8.69 kts Grid 066
> Barometer 688.9 mb (10293. ft)
>
> Ethan.Dicks_at_amanda.spole.gov
http://penguincentral.com/penguincentral.html
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Received on Mon Jan 26 2004 - 12:38:58 GMT