1 Nov
2024
1 Nov
'24
3:43 p.m.
There was a "Killer Poke" on the commodore PET that would alter the video
horizontal output frequency, which had the effect of physically damaging
the video hardware as the high voltage was generated by the flyback
transformer.l and there was no regulation.
It's mere existence made my father paranoid about machine code
programming. I was probably 10 at the time.
On Sat, 2 Nov 2024, 8:57 am Cameron Kaiser via cctalk, <
cctalk(a)classiccmp.org> wrote:
I had remembered the HCF as being a z-80 thing,
so I searched for it.
All I can find says it was 6800, not 6502.
The NMOS 6502 has a number of undocumented lock-up opcodes. However, they
arise
as a consequence of its instruction decoder PLA and weren't intended for
testing like the 6800 HCF. They were eliminated in the 65C02, though later
versions add the STP opcode as an intentional way to halt the CPU until
reset.
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Cameron Kaiser * Floodgap Systems * www.floodgap.com *
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-- Eggheads unite! You have nothing to lose but your yolks. -- Adlai
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