of COURSE this was EXACTLY what we all used our Commodore 64s to do, to balance our budget

also to improve our hand/eye dexterity

Siri, what were the very first RAM addresses we all POKEd

@natecull

I remember a classmate at school messing about with poke on an apple ii.

It ended up with smoke coming out the floppy drive.

@algorev @alanz

POKE put raw data into raw RAM addesses.

Most of the Commodore hardware chips were directly controlled by RAM addresses. No OS preventing you from doing anything.

On early PETs you could actually blow up the screen by setting some kind of refresh rate to the wrong speed or voltage.

Doesn't surprise me you could do the same to a disk drive.

@natecull @alanz @algorev Especially given just how much software control the Apple II had over its drives.

Maybe just leave all four phases of the head stepper motor on? That might be enough to smoke a weak drive...

Also worth noting that a lot of Apple II I/O works on reads (PEEK), not writes.

So, if I wanted to smoke a drive from BASIC, I might try...

10 PEEK(C0EA): REM SELECT DRIVE 1
20 PEEK(C0E1): REM PH0 ON
30 PEEK(C0E3): REM PH1 ON
40 PEEK(C0E5): REM PH2 ON
50 PEEK(C0E7): REM PH3 ON
60 PEEK(C0E9): REM MOTOR ON
RUN

Then just let it sit for a while.
@natecull @alanz @algorev I'd want to turn the motor on first, then enable the stepper phases now that I think about it - IIRC that order is needed for it actually select the drive.

The flexibility enabled by the CPU having direct control of the stepper motor phases has created... interesting... results. Quarter-tracking was common in copy protection, and more recently, @JBrooksBSI@twitter.com figured out how to do shingled magnetic recording.

With a disk controller and drive from 1978 (IIRC writing does need more CPU, though, to keep up with the drive).
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@bhtooefr @alanz @algorev

tfw your 8-bit computer simulation needs to have an entire quantum physics subsystem to correctly model the magnetic domains of the disk drive just so you can read the copy-protection / demoscene intro / quantum cryptography / hyperspace portal used by Super Retro Space Smashers III

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