[HN Gopher] Weak bits floppy disc protection: an alternate origi... ___________________________________________________________________ Weak bits floppy disc protection: an alternate origins story on 8-bit Author : scarybeast Score : 19 points Date : 2020-06-27 21:08 UTC (1 hours ago) (HTM) web link (scarybeastsecurity.blogspot.com) (TXT) w3m dump (scarybeastsecurity.blogspot.com) | dunham wrote: | It's much simpler than weak bits, but I remember one of the | Ultima games for DOS had a track with a small sector embedded in | the middle of a long sector. So from the point of view of the | controller after decoding, there were more sectors than could be | written onto a track. | | All the copy protection did was decrypt itself, read the starting | address of the executable from a sector on that track, and jump | to it. My fix was to just stuff that address back into the | executable header. (I had actually purchased the game, I was just | tired of having to insert the floppy every time I ran it off of | the hard drive.) | mrlonglong wrote: | Fabulous explanation of how they did copy protection in the old | days. I remember the 8271 well. I'm not sure why they used such | an old chip with the BBC B, as it was quite expensive. The WD1770 | was better and cheaper. | mrlonglong wrote: | I preferred the NEC uPD765 though. Higher density. ___________________________________________________________________ (page generated 2020-06-27 23:00 UTC)