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7698ElfTools & Enhanced SimElf Simulator in JavaScript

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  • aa3nm
    Jun 2, 2011
      In the early days of 1802 life, storing programs became a consideration. RCA, in their VIP, Quest Electronics in their Super ELF, and Netronics in their ELF II each supported a slightly different format for storing and reloading data via cassette tapes.

      As I recall, each format was similar in some ways to what was referred to as Kansas City Standard - but it was not the same.

      Basically they each whipped the Q around to create square waves in the audio Freq. with tone or duration changes to represent 1s and 0s... This drove the mic input of the cassette recorder. Upon playback, with the earphone fed into sort of a limiter/clipper circuit they edge detected the distroted audio into the EF line to recover the timing and thus the bits.

      In or around 2002 Richard Dienstknecht (r.dienstknecht@...
      I hope I got it right) pulled together a rough (by his description - rather nice by mine) piece of PC code called ElfTools (look in the files section) that accepted/generated wave file formatted copies of these cassette recordings (recorded through the PC line in/out). ElfTools included support for 2 of the 3 formats and has a bunch of knobs to twiddle so it recovers tapes with many sins. Richard has recently undertaken to improve the tool and add the third format. He is on the group and may chime in (my changing the thread may help).

      If this seems like a worthwhile capability for your project, I suggest information sharing between you two as the synergistic result is likely to be easier/quicker & better.

      73

      Steve



      --- In cosmacelf@yahoogroups.com, "whd_whd_whd" <whd_whd_whd@...> wrote:
      >
      >
      > I'm not sure what you mean about the second part cassette tape stuff.
      > Do you mean the ability to load in .BIN files?
      >
      >
      > --- In cosmacelf@yahoogroups.com, "aa3nm" <steve@> wrote:
      > >
      > >
      > > Also, just a thought - the old hardware by RCA Quest and Newtonics could load from a cassette tape. ELFTools was developed to pull these cassette formats through .wav files into .bin files and vice versa cleaning up noise along the way. The formats are fairly known. There should also be code in various formats for doing some of it depending on who raises a hand. Adding that kind of feature could also add value.
      > >
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