November 5, 2012 – Metatronics Extent-80

November 5, 2012 – Metatronics Extent-80


  

    Scot Silvestri provided some pictures of a Metratronics Extent-80 he found in the trash. The Extent-80 apparently allowed for up to 8 disk drives on a Model I.
    The product announcement in the 12/81 issue of 80 MICROCOMPUTING read …
            “Metatronics (a subsidiary of Meta Technologies Corp., as of September 1, 1981) introduces a unique device allowing the connection of as many as 8 disk drives to a TRS-80 Model I computer. Its integrated design is compatible with application software running under VTOS, LDOS, NEWDOS/80, NEWDOS+ and TRSDOS 2.3. Features include a U.L.-approved power supply, power-monitor LED, operating environment protection circuitry, high-impact metal case and gold-plated contacts. Complete with instructions and patch program diskette for configuring your favorite operating system.”         
    Glenn Emelko advised …
            I designed this product for MTC, and did all of the OS patches for TRSDOS, LDOS, and Newdos/80 personally. The device decoded the four drive address lines so that codes 1, 2, 4, and 8 (0001, 0010, 0100, and 1000) addressed the first four drives 0-3 directly. Other combinations of the drive select lines then selected subsequent drives allowing addressing of drives 4 to 7 (iirc it was 0011, 0101, 0110, and 0111 respectively), and we internally experimented with a 15 drive system using 8,9,A..E for the next drive numbers but never released it that way. One code 0000 was reserved for no drives selected. The operating system patches were tricky but once complete it worked great.         


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3 Comments

  1. Am I right to assume that this worked by assigning the 2nd side of the first to the fourth drive, 2nd to 5th, and so on?

  2. I designed this product for MTC, and did all of the OS patches for TRSDOS, LDOS, and Newdos/80 personally. The device decoded the four drive address lines so that codes 1, 2, 4, and 8 (0001, 0010, 0100, and 1000) addressed the first four drives 0-3 directly. Other combinations of the drive select lines then selected subsequent drives allowing addressing of drives 4 to 7 (iirc it was 0011, 0101, 0110, and 0111 respectively), and we internally experimented with a 15 drive system using 8,9,A..E for the next drive numbers but never released it that way. One code 0000 was reserved for no drives selected. The operating system patches were tricky but once complete it worked great 🙂

    Glenn

    PS you can find me pretty easily with a web search, if you would like to make contact.

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