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Thread: Olivetti M24/AT&T 6300/Xerox 6060 Display Enhancement Board (DEB) materials available

  1. #1
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    Default Olivetti M24/AT&T 6300/Xerox 6060 Display Enhancement Board (DEB) materials available

    While I haven't tested the hardware yet, I've archived the software and manuals for the DEB:

    ftp://ftp.oldskool.org/pub/drivers/A...Board%20(DEB)/

    What's the DEB?

    The DEB is a rare upgrade board for the M24's Video Display Controller (VDC). The VDC is capable of CGA emulation as well as a 640x400x2 mode, and the ability to have two 320x200x4 CGA graphics pages. The DEB sits in one of the two 16-bit slots on the M24 motherboard and connects to the VDC via a ribbon cable, and adds three more 640x400 bitplanes. These can be combined with the VDC's bitplane into 4 total bitplanes, giving 16 colors in 640x400. The DEB can also operate in only 3 bitplanes, and let the VDC do whatever it wants, then combine the result. The can be used to create a 640x400x8-color graphics screen with, for example, quickly updating scrolling text or supplemental graphics coming from the VDC.

    The DEB also has a hardware lookup table to translate RAM values into pixel colors, and it can cycle through colors in a "dithering" effect that allows you to create additional colors via temporal dithering (ie. alternating between 2, 3, or 4 colors every display cycle). While cycling through 2-color combinations can be interesting on a color monitor (136 unique combinations, about 40 of which would not flicker distractingly), hooking up a monochrome monitor is potentially much more interesting: The colors are translated to 16 shades of gray, and the monitor itself has somewhat slow phosphors. Because the display is analog, has slow phosphors, and harsh flickering would not be perceivable, this means up to 4 color combinations could be used, increasing the number of available grayscale levels from 16 to 3876. (With bit-banging it might be possible to switch palettes every scanline, allowing more than 16 onscreen at once, but this is unverified.) The LUT is also capable of cycling through colors spatially (it has a counter that updates on every new pixel), but the usefulness of this is not yet obvious to me. It can also "blink" pixels between colors, like when you set the blink attribute in text mode -- the usefulness of that is dubious at best.

    Additionally, since the DEB is a separate board with its own display output, it is possible to connect both a monochrome and a color monitor to the system at the same time (although they share the same memory space so the applications for this is limited.)
    Offering a bounty for:
    - The software "Overhead Express" (doesn't have to be original, can be a copy)
    - A working Sanyo MBC-775, Olivetti M24, or Logabax 1600
    - Documentation and original disks for: Panasonic Sr. Partner, Zenith Z-160 series
    - Music Construction Set, IBM Music Feature edition (has red sticker on front stating IBM Music Feature)

  2. #2
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    I've always wanted to see the DEB in action! If memory serves, Windows 2.11 and onwards have drivers specifically for it. Was there anything else that made use of it out of the box?

  3. #3
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    This is great - thanks for posting this! I never realised the DEB was closer to a replacement video card - somehow I thought it was a simple daughterboard or something like that!

    Also from a quick scan of the documentation it seems you can actually have two monitors connected at the same time - now seeing that in action would be awesome!

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    Quote Originally Posted by MrArgent View Post
    I've always wanted to see the DEB in action! If memory serves, Windows 2.11 and onwards have drivers specifically for it. Was there anything else that made use of it out of the box?
    GEM has a driver for the DEB too.

  5. #5
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    Quote Originally Posted by MrArgent View Post
    I've always wanted to see the DEB in action! If memory serves, Windows 2.11 and onwards have drivers specifically for it. Was there anything else that made use of it out of the box?
    Out of the box, I think CSHOW had a DEB driver, but I'd never heard of anything supporting it until John mentioned GEM had a driver for it (!)

    Quote Originally Posted by Valerio View Post
    Also from a quick scan of the documentation it seems you can actually have two monitors connected at the same time - now seeing that in action would be awesome!
    Well, read further: One monitor shows the VDC and the other shows the DEB. That means both monitors will display VDC memory, and the other monitor will display DEB memory -- so it's not really the same thing as two-monitor support in DOS like we have come to expect from CGA+MDA.

    Someday I'll hook it up and provide a demonstration -- thankfully the package comes with example GWBASIC programs, so I won't have to try to decipher the LUT instructions (which appear more complicated than they need to be).
    Offering a bounty for:
    - The software "Overhead Express" (doesn't have to be original, can be a copy)
    - A working Sanyo MBC-775, Olivetti M24, or Logabax 1600
    - Documentation and original disks for: Panasonic Sr. Partner, Zenith Z-160 series
    - Music Construction Set, IBM Music Feature edition (has red sticker on front stating IBM Music Feature)

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