XPost: alt.comp.os.windows-11, comp.os.linux.advocacy, comp.sys.mac.advocacy   
   From: nospam@needed.invalid   
      
   On Thu, 11/20/2025 7:39 AM, Daniel70 wrote:   
   > On 20/11/2025 11:17 pm, J. P. Gilliver wrote:   
   >> On 2025/11/20 11:34:5, Daniel70 wrote:   
   >>> On 19/11/2025 12:22 am, J. P. Gilliver wrote:   
   >>   
   >> []   
   >>   
   >>>> I think virtually all movie DVDs were (are, for the small market that's   
   >>>> still making and buying them!) dual-layer, except for very short movies.   
   >>>>   
   >>> So that would rely on the DVD drives being able to read these Dual-sided   
   >>> disks. Can't say I've ever noticed that capability!!   
   >>   
   >> No, dual _layer_, not dual _sided_.   
   >>   
   >> I've just had a look through my DVDs (probably for the first time in   
   >> years!), and I don't _think_ I've got any double-layer, but I'm not   
   >> sure; I assume they'd look a slightly different colour? I think the   
   >> longest is 111 minutes, and I'm not sure what the limit is for DVD5   
   >> (single layer). I do have something 199 minutes, but that's on two discs   
   >> (and the box explicitly says they're DVD5); that's a TV series   
   >> (THHGTTG), so no problem it being on two.   
   >   
   > Hang on, I'll just grab a HHGTTG Season out of my DVD rack.   
   >   
   > Bugger!! It's not there!! What have I done with it??   
   >   
   > In any case, another goodie ... Red Dwarf Series Two (the actual disk is   
   stuck in the TV's DVD player ATM) Six Episodes, each about 30min, so about   
   3hrs on one single DVD. Extras only on the second disk.   
   >   
   >> I'm pretty sure there was never a double-_sided_ (DVD - I know there   
   >> _were_ for floppies) drive; you just had to turn the disc over!   
   >>   
   > As I mentioned elsewhere, I did/Do have one or two of them.   
      
   Maybe that is DVD-RAM ? Those come in a cartridge.   
      
      https://en.wikipedia.org/wiki/DVD-RAM   
      
   Regular DVDs have a spiral groove for the recording surface.   
   Whereas DVD-RAM is concentric circles and it has random   
   access like it was a HDD. The seek time is not likely to be   
   all that fast.   
      
   There were also MO discs (magneto-optical). If you were taking   
   a four colour separation to the printers, you might carry the   
   necessary files on a weird thing like that. On the knowledge   
   that the printers desk has one of those for incoming files.   
      
      https://en.wikipedia.org/wiki/Magneto-optical_drive   
      
   Some of these weirdo things, are long gone, and the prices   
   reflect that.   
      
      Paul   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)