[ Retro Scan of the Week ] A 1985 Solid State Drive

November 5th, 2012 by Benj Edwards

SemiDisk Solid State Disk SSD Disk Drive Emulator Ad - 1985This IS your daddy's SSD.

Back in January, I traced the evolution of the Solid State Drive from its 1978 origins to the present in a PC World slideshow. From that experience, I learned that SSDs, as a product class, were far older than most people realize.

Case in point: Seen here is an advertisement for a 1985-era SSD called the SemiDisk. The company behind this early SSD, SemiDisk Systems, sold a wide range of "disk emulators" (as they were called back then) for platforms like S-100 bus systems, the TRS-80 Model 2, and the IBM PC. All of them used solid-state RAM chips to achieve read and write speeds far beyond those of rotating platter drives at the time.

The 2 megabyte SemiDisk for the IBM PC retailed for $1,795 in 1985. That's about $3,860 today when adjusted for inflation. Amusingly, at that vintage price rate — about $1,930 per megabyte — a 256 GB SemiDisk SSD would cost over $494 million today. Yep, that's a 494 followed by six zeroes.

Of course, you can buy a 256GB flash-based SSD right now for under $180. Not bad.

[ From BYTE, September 1985, p.329 ]

Discussion Topic of the Week: When did you buy your first solid state PC drive? How big was it?



6 Responses to “[ Retro Scan of the Week ] A 1985 Solid State Drive”

  1. Jaybee Says:

    I didn't. Dad did. The TI 99/4a I grew up on was tricked out, including a Horizon RAM Disk. A glorious 256 kilobytes of NiCad battery-backed SRAM just waiting to unleash data upon my CPU as fast as the expansion bus could move it.
    I actually just recently set that computer back up for a bout of nostalgia. Then spent two days finding a working setup floppy for the RAM disk.

    The first one I bought myself was a 30GB boot drive for the computer I'm using right now.

  2. Matt Says:

    This board looks almost EXACTLY like the sound board in my ancient Crystal Castles arcade machine.

  3. arlandi Says:

    CMIIW:
    this "disk" uses RAM Chips like those used in RAM so the write cycle are in theory unlimited. unlike SSDs that have limit to their write cycles (although it is very high with today's tech).

  4. Benj Edwards Says:

    That's true, arlandi. As a result, this board would lose its stored contents when the machine turned off — unless continually powered by a backup battery, a feature which many early RAM-based SSDs included.

  5. TandyMan100 Says:

    Well, my TRS-80 Model 100 *technically* has an SSD… all 32k of it. And I am using a 32GB Class10 SD Card as a hard drive in my EEE PC 900 right now.

  6. Michael Enkelis Says:

    Just as a bit of history, I was the programmer who developed the CP/M drivers
    for this board.
    The installer would probe the cpu and select ether a 8080 or Z80 optimized driver for loading.
    At my office we used multiple SemiDisk cards installed in a IC wafer testing system to hold test result data.

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