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Re: MITS / Pertec / ICOM Attache (Altair)

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  • wtsnet
    Hi David, Congratulations on getting an Attaché. The first computer I bought was an Attaché. A few of us at Pertec bought an Attaché from Burcom, the
    Message 1 of 6 , Mar 17, 2002
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      Hi David,

      Congratulations on getting an Attaché. The first computer I bought
      was an Attaché. A few of us at Pertec bought an Attaché from Burcom,
      the Houston, TX Altair store. We paid $307.50 each and also bought
      the companion Sanyo 9" composite video monitor. The problem then was
      the same as now. Boards and drives cost too much to get an Attaché
      running. It took me twenty years to find a supply of Altair boards. I
      have about 100 and paid over $8K. I won't be selling them cheap. I
      paid $100/board just to make sure I could get them. I didn't want to
      wait another twenty years.

      The first thing I noticed about the Attaché was the case. It is built
      like luggage, but has no keyboard cover or handle. I took the top off
      and only put it on when I store the machine. Next, I found the
      keyboard and video boards. The keyboard is not that great and neither
      was the video. The video is 16X64 and mine flickered when scrolling.
      I removed both. The video board only uses the S100 buss for power.
      Input is RS-232 serial. Later, I took an S100 connector and attached
      a power cable. I can use the video external to the chassis. I ground
      off the rivets and removed the keyboard mounts.

      Next, I removed the bottom part of the case and added rubber feet.
      The result is a small, light machine with an open top and a small
      footprint. I used it to test and repair boards and the open top was
      handy. The part of the chassis that covers the power supply is a
      handle for carrying. Later, I put the bottom back on. The area where
      the keyboard was can store small parts or a couple of boards. Here is
      a picture of the machine in its current state.
      http://www.VirtualAltair.com/Attache%20Side.jpg. I moved the reset
      switch to the front to get it away from the off switch.

      I got boards when I worked at Vector Graphic. Vector Graphic boards
      expect a motherboard with termination on the buss. Some don't work in
      an 18-slot Altair. The good news is that they work in the Attaché 10-
      slot motherboard. The same motherboard is found in the rare 8800b dm
      and sm. The first board in the picture is a MITS 2SIO for Altair
      compatibility. The second board is a Tarbell 1011D controller to run
      8-inch SSSD CP/M. The third board is a Vector Graphic 64K Dynamic
      memory. The fourth board is a Vector Graphic Z80. The fifth board is
      a Vector Graphic Floppy/Hard Disk controller. The last board is a
      Vector Graphic Bitstreamer II serial/parallel for Vector Graphic
      software compatibility.

      The Vector Graphic Prom/Ram III is not shown. It burns 2708 Proms and
      contains the Vector Graphic boot prom plus two custom proms. One prom
      is a Vector Graphic Serial Monitor, modified to work at 6MHz. The
      other prom is a Tarbell Boot Prom modified for Pertec floppy drive.
      Pertec 8-inch floppy drives. I also modified a CP/M BIOS for 8-inch
      Pertec floppies and the 2SIO. I have another version for the

      I made modifications the back of the chassis.
      http://www.VirtualAltair.com/Attache%20Rear.jpg. The first three DB-
      25 connectors are serial ports from the Bitstreamer II. Below that is
      a 9-pin D connector. This connector goes to a fuse block I mounted on
      top of the transformer and connected to buss power. This is the
      connector used by Vector Graphic to power peripherals. I can use it
      for drives or the external MITS video I made. The next two DB25
      connectors are for the MITS 2SIO. Below these is a 34-pin connector
      for Vector Graphic 5.25" diskette drives. The vertical 50-pin
      connector is for 8" floppies. I had to lengthen the hole for the
      connector. The serial number is 100-000082. The connector to the
      right of the label is for MITS or Vector Graphic composite video (not
      used now). The small hole is for the original reset switch. Note that
      your hand has to pass over the on/off switch to get to reset.

      That is how I got my Attaché running. I saved all the pieces and
      could restore the machine to almost original condition, but it works
      too good. Contact me if you are interested in Vector Graphic boards.
      Note: Pertec may have intended to use ROM BASIC. The only doc I have
      for ROM BASIC is specific to the Attaché. Also FYI, at the time of
      the Attaché, ICOM was no longer a company. It was acquired along with
      MITS to form the Pertec Microsystems Division. ICOM became a product
      line and was used to separate products from the MITS "Business

      Tom Sanderson

      --- In altaircomputerclub@y..., david__winter <no_reply@y...> wrote:
      > Hi Steve,
      > Thanks for your reply. My machine has the 2-board set for video
      > output, so I only need the rest. An interesting point is that I
      > have the schematics for all boards. However, I don't know if the
      > Cromemco boards will work since I'll need a Turnkey board too.
      > They may operate, but the machine will still need the turnkey
      > board to boot at a specific address. Maybe my cromemco 8080
      > board integrates this feature as it has a few sockets for 1702
      > EPROMs. This board may force the ROM to start at 0000...
      > I also have a Cromemco PROM board which contains ROMs in which I
      > could read "Extended Disk Basic version 0579", that is, a May 1979
      > Extended Disk Basic.
      > I have been actively looking for Altair boards on eBay since months
      > but either the prices were too high (sort of people who think they
      > can give a high value to everything) or the boards were not the
      > ones I needed.
      > Anyhow, I'll stay patient...
      > How many Attache machines are known to exist nowadays ?
      > David.
      > --- In altaircomputerclub@y..., alltare <no_reply@y...> wrote:
      > > David,
      > >
      > > The Attache is really an Altair 8800bT. The difference, other
      > > physical appearance, is that it used a special 2-board set for
      > video
      > > and keyboard operation, instead of an external terminal. If you
      > only
      > > have one video board, that's your first problem. Of course, if
      > > use an external CRT terminal, then you don't need either board-
      > > just need a serial port. The Attache also used the 8800b CPU
      > > and for serial I/O and booting, a TurnKey board. It did not
      > normally
      > > use ROM BASIC (but it was able to), and since you already have a
      > > Tarbell disk controller, you should be able to use disk BASIC
      > > instead.
      > >
      > > Cromemco S-100 boards should work OK in the Attache. Ebay is the
      > > place to find more parts.
      > >
      > > Steve
      > > ================================
      > >
      > > --- In altaircomputerclub@y..., david__winter <no_reply@y...>
      > > > Hi there,
      > > >
      > > > I acquired a MITS/ICOM Attache machine. Since thie machine is
      > > > really rare (around 200 made, mine being #32), maybe some of
      > > > you need to know that it is an improved Altair 8800 with
      > > > built-in keyboard, video board, BASIC in ROM, etc.
      > > >
      > > > My machine is missing EVERY board except the video board.
      > > > I have just acquired a Tarbell cassette board with docs, and now
      > > > need the other boards: CPU, EPROM (BASIC), SIO, PIO, RAM, etc.
      > > >
      > > > I do have some Cromemco S-100 boards, but I don't know if they
      > > > would work on my Attache. I didn't try anything yet.
      > > >
      > > > Anybody has spare Altair boards at fair prices ?
      > > >
      > > >
      > > > Bye,
      > > >
      > > > David.
    • alltare
      Tom s right- the Attache video boards provide a pretty crude display of only 16 lines of 64 characters. There s no addressable cursor, either (I never noticed
      Message 2 of 6 , Mar 19, 2002
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        Tom's right- the Attache video boards provide a pretty crude display
        of only 16 lines of 64 characters. There's no addressable cursor,
        either (I never noticed any flicker, though). But there was one big
        advantage to that low resolution display. If you ran the composite
        video output into an RF modulator, you could hook it up to the
        antenna terminals of a TV set instead of a real video monitor. I did
        this with my Attache, using a modulator that I bought at Radio
        Shack. All TVs are limited by the sound trap filter, so 64
        characters/line is about the max that you can display on a TV. The
        higher frequency video information of the standard 80-character-per-
        line displays would cause the TV picture to tear and become
        unreadable. (You could get more bandwidth out of a black-and-white
        TV by doing a little hacking: Instead of putting an RF signal into
        the TV's antenna terminals, you could input the composite video
        signal directly into the first video amplifier, and disconnecting the
        first video amp from the preeceeding tuning and filtering circuitry.
        This would eliminate the sound trap problem and give you a clean
        picture, even at 80 characters/line. This is what Tandy did with
        their original TRS-80 monitor. Did you ever wonder why their
        official monitor looked so much like a TV? They just left out the
        tuner section of a cheap TV, then doubled the price).

        Remember that back when MITS made the Attache, real video monitors
        were still pretty expensive, even the little 9" Sanyo. Using a TV
        eliminated that additional cost.

        David- If you want to try using a TV, I think you can still buy
        modulators at Rad Shak, but the video input of your VCR (not
        available back then) will work as well. The VCR will act as the
        modulator. (The only problem I see is that you'll probably need a
        U.S. type NTSC TV and VCR. Don't you guys use the PAL standard in


        --- In altaircomputerclub@y..., wtsnet <no_reply@y...> wrote:
        > Hi David,
        > Congratulations on getting an Attaché. ... The keyboard is not that
        great and neither
        > was the video. The video is 16X64 and mine flickered when
        > I removed both. The video board only uses the S100 buss for power.
        > Input is RS-232 serial ...
        >Tom Sanderson
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