[HN Gopher] The Ultimate Commodore 1541 Disk Drive Talk [video]
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The Ultimate Commodore 1541 Disk Drive Talk [video]
Author : Audiophilip
Score : 68 points
Date : 2021-09-16 16:10 UTC (6 hours ago)
(HTM) web link (www.pagetable.com)
(TXT) w3m dump (www.pagetable.com)
| gfaure wrote:
| I was lucky enough to see this talk in person at the Vintage
| Computer Festival West this year.
|
| One of the absolute highlights (timestamp
| https://youtu.be/_1jXExwse08?t=1903) was the incredible work on a
| custom disk loader that increased the throughput from 400 bytes/s
| to 7.5 kB/s! A writeup of that optimisation work, which was only
| published in 2013, can be found here:
| https://www.linusakesson.net/programming/gcr-decoding/index....
| crispyambulance wrote:
| The same person also wrote "The TTY Demystified" also a very
| good read:
| https://www.linusakesson.net/programming/tty/index.php
| c64d81744074dfa wrote:
| > increased the throughput from 400 bytes/s to 7.5 kB/s
|
| Since then someone has come up with yet another custom disk
| loader that's more than twice as fast as that one!
|
| https://csdb.dk/release/?id=197710
|
| It's incredible that people are still pushing the limits of the
| stock C64 system these days...
| buescher wrote:
| "In order to shave off a cycle from every instruction that
| modifies another one, the entire loop will be placed in the
| zero-page." Oh wow.
| TacticalCoder wrote:
| If you like that kind of stuff, here's the 256 bytes (!) C64
| intro "A mind is born" and its technical explanation... It's
| using that same zero-page trick:
|
| https://linusakesson.net/scene/a-mind-is-born
|
| I have no words... These coders are amazing!
| localhost wrote:
| I wrote one of the early fastload cartridges for the 1541 (Epyx
| had the famous one, but mine also did a fast format, and drive to
| drive backup across two 1541s) and am looking forward to going
| down memory lane with this talk! Thanks for the share!
| fatnoah wrote:
| I had the Epyx one, but I never realized there were others.
| localhost wrote:
| Mine was the GT4 cartridge, distributed by Pro-Line Software,
| the same folks who distributed WordPro 64, WordPro for the
| Vic-20 which I did the port for and likely some versions for
| the PET as well though that was probably Pro-Micro software
| IIRC.
| comeonseriously wrote:
| I remember, as a kid, playing copy protected games at night and
| hoping my dad didn't wake up mad at me because of all the CLACK
| CLACK CLACK CLACKing that the drive head was doing as the
| protection scheme was slamming it all the way to one side to read
| some bit of data.
|
| Good times, man.
| allenu wrote:
| Looking forward to watching this. His previous talks, such as the
| Ultimate Commodore 64 Talk, have been comprehensive, clear, while
| being very concise on each bit of info.
| anyfoo wrote:
| I'm only 20 minutes in, but I can already tell you that you
| won't be disappointed. I feel like after just about a third of
| the video I already fully understand the physical _and_ logical
| disk format. Like the previous videos, it 's chock full of
| dense information presented with very clear visualization.
| rzzzt wrote:
| Does a high quality version of the Ultimate C64 Talk exist
| somewhere? I only see fairly low bitrate versions of it. (The
| embed on Michael's website is dancing postage stamp-sized.)
| Audiophilip wrote:
| I'm not sure there is one. There are some mirrors[0] that
| have a copy of the original recording[1], but apparently
| still very low-res.
|
| [0]: https://events.ccc.de/congress/2008/wiki/Conference_Reco
| rdin...
|
| [1]: http://ftp-stud.hs-
| esslingen.de/Mirrors/CCC/25C3/video_h264_...
| anyfoo wrote:
| Not exactly what you're asking for, but
| https://www.youtube.com/watch?v=ZsRRCnque2E while being 480p
| and rather noisy, was very sufficient for me to watch and
| enjoy the talk back in the day. The presented material does
| not suffer much on the relatively low resolution.
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(page generated 2021-09-16 23:01 UTC)