tag:blogger.com,1999:blog-3024470480937744884.post5425692117789435112..comments2024-03-18T04:40:58.042-07:00Comments on Security: Turning a £400 BBC Micro (1981) into a $40,000 disc writer (1987)Chris Evanshttp://www.blogger.com/profile/01004765479735675808noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-3024470480937744884.post-25060995503565611952020-07-17T03:02:09.583-07:002020-07-17T03:02:09.583-07:00Wonderful job on using the Beeb to the last drop. ...Wonderful job on using the Beeb to the last drop. Thanks for the effort.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3024470480937744884.post-59402320687062342842020-07-12T10:32:57.290-07:002020-07-12T10:32:57.290-07:00We use the 1571 drive’s 6526 clocked at 2 MHz in t...We use the 1571 drive’s 6526 clocked at 2 MHz in the ZoomFloppy to transfer raw GCR bits. Rate is 500 Kbit/second. <br /><br />https://rdist.root.org/2010/09/21/building-the-zoomfloppy-slides/Unknownhttps://www.blogger.com/profile/11280644250533859717noreply@blogger.comtag:blogger.com,1999:blog-3024470480937744884.post-32015665656566290022020-07-10T21:54:20.320-07:002020-07-10T21:54:20.320-07:00>I did not work out how to get the shift clock ...>I did not work out how to get the shift clock running continuously and smoothly. Even with attempts at precise timing for shift register reloading... reloading the shift register incurs a delay before shifting resumes.<br /><br />This is a hardware bug http://forum.6502.org/viewtopic.php?t=342#p2310 , rather famously the reason for C64 having cripplingly slow (300 byte/s) floppy drive communication implemented thru bitbanging in software despite using fixed 6526 CIA. Previous VIC-20 used 6522 and floppy drives had to stay compatible https://en.wikipedia.org/wiki/Fast_loader<br /><br />Dropping this compatibility and using 6526 CIA hardware shift register results in C128+1571 combo reaching ~5KB/s (as you would expect from 6526 clocked at 2MHz)<br /><br /><br />>video-to-disc cable<br /><br />similar to video-to-antena concept :)<br />https://osmocom.org/projects/osmo-fl2k/wikiRasz_plhttps://www.blogger.com/profile/08541243565385658679noreply@blogger.com