Loading ...
Sorry, an error occurred while loading the content.

16k Static board for 680 system and more

Expand Messages
  • Craig Landrum
    Bought what I thought was a bunch of 88-16MCS cards off ebay some time back and looking at them now (while building up my 8800), I found that one of them is a
    Message 1 of 16 , Jul 20 3:58 PM
    • 0 Attachment
      Bought what I thought was a bunch of 88-16MCS cards off
      ebay some time back and looking at them now (while building up
      my 8800), I found that one of them is a 680b-BSM static card
      for a 680 system. The board is really clean and I'd like to
      either sell it or trade for an 8800 88-16MCS board.

      I also have an 88-PMC8 8k EPROM board (uses 2708's) and board
      description claims it can program proms - it's only
      partially populated (all sockets and regulators are installed, but
      board needs all of the 74xx bus interface/logic chips). Of course
      this means that I'm now in the market for a 1702-based 88-PMC
      prom card (which is what I thought I was getting). If anyone
      has one to sell or trade, let me know.

      FYI, I now have a small stock of 4200ACC static RAM chips for
      the 16K boards if anyone needs one or two.

      Finally, I'm loooking for a pinout description of the cable that
      runs from the two disk controller cards to the Altair 8 inch
      disk unit. one of the connectors on one end has been removed and
      I'll have to replace it to get it working again. but I need
      the pinouts. Any help apppreciated.



      --
      Craig Landrum
      Chief Technical Officer
      mindwrap, inc.
      Phone: (540) 675-3015 x 229
      Fax: (540) 675-3130
      email: craigl@...
    • Dave Freeman
      ACP Components 1317 E. Edinger Santa Ana, CA 92705 ACP has several hundred 4200 chips in stock Call Jim for help. Thanks ... [Non-text portions of this message
      Message 2 of 16 , Jul 21 10:37 AM
      • 0 Attachment
        ACP Components
        1317 E. Edinger
        Santa Ana, CA 92705
        ACP has several hundred 4200 chips in stock
        Call Jim for help.
        Thanks
        On Jul 20, 2005, at 3:58 PM, Craig Landrum wrote:

        > Bought what I thought was a bunch of 88-16MCS cards off
        > ebay some time back and looking at them now (while building up
        > my 8800), I found that one of them is a 680b-BSM static card
        > for a 680 system.  The board is really clean and I'd like to
        > either sell it or trade for an 8800 88-16MCS board. 
        >
        > I also have an 88-PMC8 8k EPROM board (uses 2708's) and board
        > description claims it can program proms - it's only
        > partially populated (all sockets and regulators are installed, but
        > board needs all of the 74xx bus interface/logic chips). Of course
        > this means that I'm now in the market for a 1702-based 88-PMC
        > prom card (which is what I thought I was getting).  If anyone
        > has one to sell or trade, let me know.
        >
        > FYI, I now have a small stock of 4200ACC static RAM chips for
        > the 16K boards if anyone needs one or two.
        >
        > Finally, I'm loooking for a pinout description of the cable that
        > runs from the two disk controller cards to the Altair 8 inch
        > disk unit.  one of the connectors on one end has been removed and
        > I'll have to replace it to get it working again. but I need
        > the pinouts.  Any help apppreciated.
        >
        >
        >
        > --
        > Craig Landrum
        > Chief Technical Officer
        > mindwrap, inc.
        > Phone: (540) 675-3015 x 229
        > Fax:   (540) 675-3130
        > email: craigl@...
        >
        >
        > ---- SPECIAL NOTICE CONCERNING "SPAM"  ----
        > If this message appears to be junk mail that has nothing to do with
        > our group, there are things you can do to prevent receiving more of
        > the same.  Go to our Yahoo group's website, sign in, open the FILES
        > folder, and read the text file called "Blocking Spam" for infomation
        > about your options. 
        > --- Steve, your group moderator
        >
        >
        >
        > YAHOO! GROUPS LINKS
        >
        > ▪  Visit your group "altaircomputerclub" on the web.
        >  
        > ▪  To unsubscribe from this group, send an email to:
        >  altaircomputerclub-unsubscribe@yahoogroups.com
        >  
        > ▪  Your use of Yahoo! Groups is subject to the Yahoo! Terms of
        > Service.
        >
        >


        [Non-text portions of this message have been removed]
      • Steve
        The 680 static RAM card uses the same chips as the 16K static RAM card for the 8800 buss. The PMC-8 board was often sold as a read-only board, without
        Message 3 of 16 , Jul 21 10:11 PM
        • 0 Attachment
          The 680 static RAM card uses the same chips as the 16K static RAM
          card for the 8800 buss.

          The PMC-8 board was often sold as a read-only board, without
          programming ability. Does your board have a big rectangular inverter
          module mounted on it? If not, you can't blast 2708s.

          Which cable are you rebuilding? One of the internal cables that go
          from the 2 boards to the back panel of the computer, or the long
          cable that goes from the back of the Altair to the back of the drive
          cabinet? Or somewthing else?

          steve
          =============

          --- In altaircomputerclub@yahoogroups.com, Craig Landrum
          <craigl@m...> wrote:
          > Bought what I thought was a bunch of 88-16MCS cards off
          > ebay some time back and looking at them now (while building up
          > my 8800), I found that one of them is a 680b-BSM static card
          > for a 680 system. The board is really clean and I'd like to
          > either sell it or trade for an 8800 88-16MCS board.
          >
          > I also have an 88-PMC8 8k EPROM board (uses 2708's) and board
          > description claims it can program proms - it's only
          > partially populated (all sockets and regulators are installed, but
          > board needs all of the 74xx bus interface/logic chips). Of course
          > this means that I'm now in the market for a 1702-based 88-PMC
          > prom card (which is what I thought I was getting). If anyone
          > has one to sell or trade, let me know.
          >
          > FYI, I now have a small stock of 4200ACC static RAM chips for
          > the 16K boards if anyone needs one or two.
          >
          > Finally, I'm loooking for a pinout description of the cable that
          > runs from the two disk controller cards to the Altair 8 inch
          > disk unit. one of the connectors on one end has been removed and
          > I'll have to replace it to get it working again. but I need
          > the pinouts. Any help apppreciated.
          >
          >
          >
          > --
          > Craig Landrum
          > Chief Technical Officer
          > mindwrap, inc.
          > Phone: (540) 675-3015 x 229
          > Fax: (540) 675-3130
          > email: craigl@m...
        • Craig Landrum
          I m hoping someone in the group has experienced this before and can recommend a fix. (Oh, I know what THAT is...) The symptom: I have a MITS CPU card and two
          Message 4 of 16 , Jul 22 10:39 AM
          • 0 Attachment
            I'm hoping someone in the group has experienced this before
            and can recommend a fix. (Oh, I know what THAT is...)

            The symptom:

            I have a MITS CPU card and two 16-MCS static cards installed.

            I turn all of the address line off and hit EXAMINE. Works.

            Then I turn on A0 and hit EXAMINE - doesn't work (the A0 light
            does not come on)

            Turn off A0, turn on A1, do EXAMINE - works

            Turn off A1, turn on A2, etc, etc through all the
            switches up to A14. Some work, some don't and I
            cannot find a pattern

            A14 - OK
            A13 - OK
            A12 - OK
            A11 - Bad
            A10 - Bad
            A9 - OK
            A8 - Bad
            A7 - OK
            A6 - Bad
            A5 - OK
            A4 - OK
            A3 - Bad
            A2 - Bad
            A1 - OK
            A0 - Bad

            My analysis:

            EXAMINE fires off a counter (IC J) that eventually results in
            three words being written to the D0-D7 lines that plug into
            the CPU board. These lines are pulled up with 4.7K resistors
            on the CPU board.

            The first count places an octal 303 (JMP) instruction on the
            bus. The second count places A0-A7 onto the D0-D7 lines, and
            the third count places the A8-A15 onto D0-D7. The fourth count
            lowers PRDY, placing the CPU in a wait state. All this is
            in the Theory of operation description for the front panel.

            All of the values are driven by 7405 chips, based on input
            from a 7404 (for the 303) and 7400 (for the address bytes).

            I hooked up a logic analyzer and verified that the 7404 and
            the 7400 were firing at the correct times - look nice and
            clean. I then went to the D0-D7 lines on the CPU board
            (easy to hook onto), to verify the output off the 7405's.
            Turns out that looking at these signals was very difficult
            (probably because the signals were flaky to begin with,
            hence causing my problem with the address lines, duh).
            Looking at the signal, the 7405 seem to work fine when
            they are required to output mostly 1's (set A0-A7 ON
            and hit EXAMINE), and seem to work when all but one are
            set to ON (A0 off, A1-A7 on for example). But when the
            switches are mostly off and one switch is ON (A0 On, A1-A7
            off), the rising edge of the "1" signal from the 7405
            appears ragged and takes a while to settle down, causing
            the CPU to think the line is "0" when it should be "1".

            I note that the A0-A7 and A8-A15 lines driven by the 7405's
            are as a result of input from one gate of a 7400 (one
            drives the top 8 bits and another 7400 drives the bottom
            8 bits). The 7404 drives four gates of another 7405, and
            this combination never seems to fail (the CPU always sees
            the JMP instruction, but fails on the addresses).

            Has anyone else experienced flaky EXAMINEs like I'm seeing
            here? I suspect that the 7405's have somehow gone "wimpy"
            and are not reponding as quickly to the 7400 input as they
            did in their younger years but this seems sort of silly
            that a chip would degrade rather than outright fail.

            Of course it could also be that the 7400 chips are flaky
            and my analyzer simply isn't catching it, somehow causing
            the 7405's to oscillate on a rising edge.

            Recommendations? Replace the 7400's?? Replace the 7405s??
            (I have 74LS00's and some SN7405N's handy). Or perhaps
            something is wrong that I am not seeing.

            Any help appreciated. Unless I can get EXAMINE working
            reliably, it's going to make booting sort of hit or miss :-)

            Also FYI:

            EXAMINE NEXT works fine (uses a different mechanism)
            DEPOSIT and DEPOSIT NEXT seem to work OK (DEPOSIT
            sometimes needs more than one hit to make it in).

            I can enter and run the following test program just fine:

            IN 333
            STA 200
            JMP 000

            When I examine location 200 it contains whatever the
            sense switches were set to. So memory and thee CPU
            seem to be able to work together OK.
            --
            Craig Landrum
            Chief Technical Officer
            mindwrap, inc.
            Phone: (540) 675-3015 x 229
            Fax: (540) 675-3130
            email: craigl@...
          • Craig Landrum
            ... Now it s Tom s 680 Static RAM card, since we traded :-) ... It looked like the PMC8 picture on the virtualaltair website, bit I don t think it had the
            Message 5 of 16 , Jul 22 10:59 AM
            • 0 Attachment
              On Friday, July 22, 2005 at 1:11 AM, Steve sent:

              >The 680 static RAM card uses the same chips as the 16K static RAM
              >card for the 8800 buss.

              Now it's Tom's 680 Static RAM card, since we traded :-)

              >
              >The PMC-8 board was often sold as a read-only board, without
              >programming ability. Does your board have a big rectangular inverter
              >module mounted on it? If not, you can't blast 2708s.

              It looked like the PMC8 picture on the virtualaltair website,
              bit I don't think it had the switch and the inverter.
              >
              >Which cable are you rebuilding? One of the internal cables that go
              >from the 2 boards to the back panel of the computer, or the long
              >cable that goes from the back of the Altair to the back of the drive
              >cabinet? Or somewthing else?

              Boards to backplane. I have a twisted pair cable and one of
              the smaller molex connectors was cut off. Tom sent me the
              pinouts, but now I'm looking for the model # for a replacement
              molex (and those slide-in crimping contacts). This molex
              appears about half the size of the CPU molex....

              Any idea where to get a molex replacement???
              --
              Craig Landrum
              Chief Technical Officer
              mindwrap, inc.
              Phone: (540) 675-3015 x 229
              Fax: (540) 675-3130
              email: craigl@...
            • Craig Landrum
              After days of chip-level debugging sessions along with an Altair BASIC boot disk generously provided by Bob, I was able to boot and run BASIC last night. Had
              Message 6 of 16 , Aug 12, 2005
              • 0 Attachment
                After days of chip-level debugging sessions along with an
                Altair BASIC boot disk generously provided by Bob, I was
                able to boot and run BASIC last night.

                Had previously been debugging the 88-DCDD system which
                had been assembled piecemeal from various sources
                (controllers from vintagemicros, disk drive from Jack,
                connector cable from Jameco, and plenty of great advice
                from Tom and others, a DCDD manual and DBL boot prom from
                Steve) and had fixed a defective braided cable, replaced
                a bad molex connector, and replaced four dead IC's on the
                controller cards.

                Last night (before I booted BASIC) I was running down a write
                problem using I/O test routines laboriously toggled in
                through the front panel. I would try a write and then
                try a read and get back all 1's. After hours of tracing
                signals using the logic analyzer and checking one-shot
                timings, I finally looked where I should have started
                at in the first place which was the actual connector on
                the back of the disk, and lo and behold, write data was
                streaming into the disk. WTF??? Data screaming in and
                nothing getting written? About 60 seconds later I
                slapped myself on the forehead, removed the diskette,
                and covered over the write protect tab. Duh. Stuff
                worked perfectly then, amazingly enough. Put the
                boot disk in and away we went. Lesson learned.

                Now that the system is alive, I'll try and do a
                facial makeover. The front dress panel is in
                really decent shape except for a few missing letters
                here and there. I grabbed a high rez scan of a
                good front panel from the web, Cleaned it up, removed
                the gray background, inverted the white bits to black
                and printed it actual size on clear mylar. I plan to
                use PhotoEZ to create a new silkscreen for portions of
                the front panel that are damaged (this is a neat
                product - see: http://www.gwengibson.com/photoez.htm
                I used it before when restoring the lettering on a
                rebuilt Chatauqua roller organ ). Will take some before
                and after pics of the dress panel.

                Stuff I'm still looking for:

                - A 88-CENT Centronics board (will buy if found or
                trade for other S100 boards)

                - A copy of Altair DOS/Editor/Assembler/Linker/Debugger

                - A second Altair Disk drive in its cabinet.

                - A repro Altair Disk aliminum dress strip to go on
                the front of the Altair Disk I now have. FYI, the
                guy that currently sells the Altair 8800 repro
                strips doesn't have them).

                I'm driving up to NJ in a week or so to pick up three
                ASR33 teletype/paper tape punch/readers and will
                rebuild one to go with this system.



                --
                Craig Landrum
                Chief Technical Officer
                mindwrap, inc.
                Phone: (540) 675-3015 x 229
                Fax: (540) 675-3130
                email: craigl@...
              • Steve
                Congratulations, Craig. It s always the simple things that cause the biggest headaches, isn t it? I m curious about your PhotoEZ project. After going to the
                Message 7 of 16 , Aug 12, 2005
                • 0 Attachment
                  Congratulations, Craig. It's always the simple things that cause the
                  biggest headaches, isn't it?

                  I'm curious about your PhotoEZ project. After going to the URL you
                  gave, and after googling for the product, it seems that the largest
                  sheet of PhotoEZ is only 12" long. How will you able to produce a
                  good ~17" silkscreen mask? Surely, you can't simply splice 2 sheets
                  together, can you?

                  steve
                  =============================

                  --- In altaircomputerclub@yahoogroups.com, Craig Landrum
                  <craigl@m...> wrote:
                  > After days of chip-level debugging sessions along with an
                  > Altair BASIC boot disk generously provided by Bob, I was
                  > able to boot and run BASIC last night.
                  >
                  > Had previously been debugging the 88-DCDD system which
                  > had been assembled piecemeal from various sources
                  > (controllers from vintagemicros, disk drive from Jack,
                  > connector cable from Jameco, and plenty of great advice
                  > from Tom and others, a DCDD manual and DBL boot prom from
                  > Steve) and had fixed a defective braided cable, replaced
                  > a bad molex connector, and replaced four dead IC's on the
                  > controller cards.
                  >
                  > Last night (before I booted BASIC) I was running down a write
                  > problem using I/O test routines laboriously toggled in
                  > through the front panel. I would try a write and then
                  > try a read and get back all 1's. After hours of tracing
                  > signals using the logic analyzer and checking one-shot
                  > timings, I finally looked where I should have started
                  > at in the first place which was the actual connector on
                  > the back of the disk, and lo and behold, write data was
                  > streaming into the disk. WTF??? Data screaming in and
                  > nothing getting written? About 60 seconds later I
                  > slapped myself on the forehead, removed the diskette,
                  > and covered over the write protect tab. Duh. Stuff
                  > worked perfectly then, amazingly enough. Put the
                  > boot disk in and away we went. Lesson learned.
                  >
                  > Now that the system is alive, I'll try and do a
                  > facial makeover. The front dress panel is in
                  > really decent shape except for a few missing letters
                  > here and there. I grabbed a high rez scan of a
                  > good front panel from the web, Cleaned it up, removed
                  > the gray background, inverted the white bits to black
                  > and printed it actual size on clear mylar. I plan to
                  > use PhotoEZ to create a new silkscreen for portions of
                  > the front panel that are damaged (this is a neat
                  > product - see: http://www.gwengibson.com/photoez.htm
                  > I used it before when restoring the lettering on a
                  > rebuilt Chatauqua roller organ ). Will take some before
                  > and after pics of the dress panel.
                  >
                  > Stuff I'm still looking for:
                  >
                  > - A 88-CENT Centronics board (will buy if found or
                  > trade for other S100 boards)
                  >
                  > - A copy of Altair DOS/Editor/Assembler/Linker/Debugger
                  >
                  > - A second Altair Disk drive in its cabinet.
                  >
                  > - A repro Altair Disk aliminum dress strip to go on
                  > the front of the Altair Disk I now have. FYI, the
                  > guy that currently sells the Altair 8800 repro
                  > strips doesn't have them).
                  >
                  > I'm driving up to NJ in a week or so to pick up three
                  > ASR33 teletype/paper tape punch/readers and will
                  > rebuild one to go with this system.
                  >
                  >
                  >
                  > --
                  > Craig Landrum
                  > Chief Technical Officer
                  > mindwrap, inc.
                  > Phone: (540) 675-3015 x 229
                  > Fax: (540) 675-3130
                  > email: craigl@m...
                • Craig Landrum
                  ... Correct - their sheets aren t large enough. Also, due to the small variations and inaccuracies in scanning, printing, etc, it is highly unlikely that I
                  Message 8 of 16 , Aug 12, 2005
                  • 0 Attachment
                    >I'm curious about your PhotoEZ project. After going to the URL you
                    >gave, and after googling for the product, it seems that the largest
                    >sheet of PhotoEZ is only 12" long. How will you able to produce a
                    >good ~17" silkscreen mask? Surely, you can't simply splice 2 sheets
                    >together, can you?
                    >
                    >steve

                    Correct - their sheets aren't large enough. Also, due to the
                    small variations and inaccuracies in scanning, printing, etc,
                    it is highly unlikely that I could generate a mylar or a
                    screen that would accurately register across the entire front
                    panel (at least not without a lot of tweaking). So what I'm
                    doing is simply making small screens that do specific
                    sections of the panel (perhaps for just one switch like the
                    ON/ OFF or EXAMINE/EXAMINE NEXT switch etc). Then I easily
                    mount the screen over the area being fixed with nice registration
                    and mask off the rest of the front panel with platsic wrap or
                    several sheets of paper, etc leaving just the area being painted
                    open.

                    PhotoEZ worked well for me when restenciling black letters over
                    polyurethaned wood and I would expect it to work even better
                    over smooth metal. On the wood project I was using Krylon
                    black spay paint and will probably try and use white or cream
                    color for the front panel. Haven't looked with a magnifier
                    yet, but at first glance the original white lettering appears
                    to be in semi-gloss or flat, so I will try that.

                    When doing these kind of things, the biggest ooops to avoid
                    is trying to apply too much paint at once, causing it to
                    wick between the stencil and the surface being painted.

                    I'm also considering spraying a final covering of clear satin
                    finish over the restored panel to protect it, but will certainly
                    try a small section first to see how it affects the appearance.
                    I wouldn't want to end up with nicely restored but fakey looking
                    panel....

                    --
                    Craig Landrum
                    Chief Technical Officer
                    mindwrap, inc.
                    Phone: (540) 675-3015 x 229
                    Fax: (540) 675-3130
                    email: craigl@...
                  • Craig Landrum
                    I m considering creating some reproduction MITS documentation binders in something like 1 inch and 1.5 or 2 inch sizes. My initial thoughts were to duplicate
                    Message 9 of 16 , Aug 12, 2005
                    • 0 Attachment
                      I'm considering creating some reproduction MITS documentation
                      binders in something like 1 inch and 1.5 or 2 inch sizes.

                      My initial thoughts were to duplicate the MITS blue lettering
                      etc on the cover and binding and also order the binders with
                      inside pockets and the clear plastic binder pocket that you
                      can slip a document title into.

                      Has anyone done this already? If not, would anyone be
                      interested in buying some from me if I ordered them in
                      quantity? Assuming I could charge about $5 a binder, would
                      there be any takers out there, and for how many binders?

                      --
                      Craig Landrum
                      Chief Technical Officer
                      mindwrap, inc.
                      Phone: (540) 675-3015 x 229
                      Fax: (540) 675-3130
                      email: craigl@...
                    • raife_e
                      ... wrote: ... Hi, I am currently looking for an aluminum 8800 repro strip , if I can t get an original. But, I don t know where to acquire one. Could you
                      Message 10 of 16 , Aug 14, 2005
                      • 0 Attachment
                        --- In altaircomputerclub@yahoogroups.com, Craig Landrum <craigl@m...>
                        wrote:

                        ...

                        > - A repro Altair Disk aliminum dress strip to go on
                        > the front of the Altair Disk I now have. FYI, the
                        > guy that currently sells the Altair 8800 repro
                        > strips doesn't have them).

                        Hi,

                        I am currently looking for an aluminum "8800 repro
                        strip", if I can't get an original. But, I don't know
                        where to acquire one.
                        Could you point me to "...the guy that currently
                        sells the Altair 8800 repro strips"..?

                        Much appreciated,

                        Raife Edwards
                      • Craig Landrum
                        ... This was the email of the guy I bought mine from a month or so ago. At that time, he charged about $40 and $10 for shipping and the item was excellent.
                        Message 11 of 16 , Aug 15, 2005
                        • 0 Attachment
                          On Monday, August 15, 2005 at 8:08 PM, raife_e sent:

                          > I am currently looking for an aluminum "8800 repro
                          >strip", if I can't get an original. But, I don't know
                          >where to acquire one.
                          > Could you point me to "...the guy that currently
                          >sells the Altair 8800 repro strips"..?
                          >
                          >Much appreciated,
                          >
                          >Raife Edwards
                          >

                          This was the email of the guy I bought mine from a month
                          or so ago. At that time, he charged about $40 and $10
                          for shipping and the item was excellent.

                          jerry.schneider@...


                          --
                          Craig Landrum
                          Chief Technical Officer
                          mindwrap, inc.
                          Phone: (540) 675-3015 x 229
                          Fax: (540) 675-3130
                          email: craigl@...
                        Your message has been successfully submitted and would be delivered to recipients shortly.