[HN Gopher] Chip-8 on the COSMAC VIP: The Character Set
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       Chip-8 on the COSMAC VIP: The Character Set
        
       Author : hggh
       Score  : 13 points
       Date   : 2024-04-28 10:35 UTC (2 days ago)
        
 (HTM) web link (www.laurencescotford.net)
 (TXT) w3m dump (www.laurencescotford.net)
        
       | Retr0id wrote:
       | My favourite quote from this series of blog posts:
       | 
       | > One thing to note about this instruction [FX1E] is that it will
       | quite happily let you sail off into the uncharted waters of
       | memory beyond the on-board 4K, because it will only wrap when the
       | offset takes the address beyond 65535. The Chip-8 programmer must
       | ensure it contains a meaningful value.
       | 
       | https://www.laurencescotford.net/2020/07/19/chip-8-on-the-co...
       | 
       | This behaviour doesn't matter much on a COSMAC VIP, but on modern
       | emulators it presents an opportunity for OOB accesses, and you'd
       | be amazed how many independent implementations stumbled across
       | this same bug. I wrote about exploiting one of them (to achieve
       | an emulator escape) here
       | https://www.da.vidbuchanan.co.uk/blog/bggp3.html
        
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       (page generated 2024-04-30 23:00 UTC)