Image Map Image Map
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 29

Thread: Atex PDP-11/34

  1. #11
    Join Date
    Jan 2019
    Location
    Vancouver, BC or San Jose, California
    Posts
    31

    Default

    After some poking around, I have found out that the grey connector goes to the green board here. https://imgur.com/a/m5N6ral Descriptions and photos of the two mystery cards.

  2. #12
    Join Date
    Mar 2006
    Location
    Salt Lake City, UT, USA
    Posts
    333

    Default

    I believe what you have is similar to, if not identical to, the system described in the article "Network World LAN offers growth path", Network World, Jan 15, 1990, pg. 25.

    "The Atex J-11 processors driving the network are based on Digital Equipment Corp. PDP-11 technology but incorporate many proprietary Atex components. [...] Atex processors [...] each have 8 MB of main memory and 300 MB of disk capacity. [...] The J-11s support 32 users and mirror one another in the event either unit fails. [IBM PS/2s] are wired into the J-11s through four rack-mounted Allied Telesis, Inc. multiport Ethernet repeaters, which in turn are connected to a 16-port Allied Telesis CentreCom 1600 transceiver."
    It looks like the one you have is slightly different and uses RS-232 ports as well as some sort of networking ports. Your photo shows an Atex board that has what looks like 8 serial ports with RJ style connector adapters on the 25-pin serial port connectors.

    A good trick for researching obscure stuff is to use Google books to search "magazines" for likely search terms. They have almost complete scans of InfoWorld, ComputerWorld and Network World in their public archives. That's how I found the article I linked above.

  3. #13
    Join Date
    Jan 2019
    Location
    Vancouver, BC or San Jose, California
    Posts
    31

    Default

    Awesome, thanks for the info! I want to connect the supposedly serial card to the machine, do I need to follow any rules when plugging it in or can I just plug it in above the memory board or above a bus grant card?

  4. #14
    Join Date
    Dec 2012
    Location
    Colorado
    Posts
    173
    Blog Entries
    1

    Default

    Was everything cabled up when you got the system? If so, you did record where every cable went? Is there a DLART on the CPU board? That will almost certainly be the console port.

  5. #15
    Join Date
    Jan 2019
    Location
    Vancouver, BC or San Jose, California
    Posts
    31

    Default

    No the system was in pieces when I had gotten it and I am referring to the ebay listing and common sense to get me through

    Is there any ways to test that the serial port is working without hooking it up to a terminal? Even if it worked, I probably wouldn't get anything out of it since I do not know the baud rate. The thing is that there are 4 little boards with 1 serial port each. Two are with 2 little LEDs, when I plug the CIO SDI card into the machine and cable it up to the small card with the 2 LEDs, one of the LEDs light up but nothing more

  6. #16
    Join Date
    Jun 2012
    Location
    UK - Worcester
    Posts
    2,998

    Default

    The problem you have is that you have too many variables...

    It is no good just plugging things in and hoping a serial port will burst into life. It won't...

    You need to get ODT working first. ODT will talk to a specific serial port - and that is all. We need to either find, or configure, that specific serial port.

    So, back to the original question posed... check the CPU board for a serial port type of device (hopefully that plugs into the gray connector). You ascertained there was a 148x device on board, so it is highly likely that there IS a serial port on the CPU board. All you have to do is to find exactly which bit of silicon it is.

    Once you have found it, we can identify the data sheet for the device. From that (hopefully) there will be pins defining the serial format (that we can measure with a voltmeter or logic probe) and the transmit and receive clocks (that can be measured with a frequency counter or oscilloscope) to determine the baudrate.

    I hope this is making sense to you?

    Dave

  7. #17
    Join Date
    Mar 2004
    Location
    Wilmette, IL (north of Chicago)
    Posts
    703
    Blog Entries
    1

    Default

    Nick,

    Is the machine in San Jose or Vancouver?

    If it's in San Jose and you haven't made much progress over the next few weeks, why not bring it VCF-West? Put it up as hands-on problem solving session and I bet you'll leave with a working machine!

  8. #18
    Join Date
    Dec 2012
    Location
    Colorado
    Posts
    173
    Blog Entries
    1

    Default

    If you have an oscilloscope, that would give you a lot of flexibility in problem solving. If not, can you get ahold of some type of RS-232 breakout box with LED indicators, or something like I bought years ago RS-232 CHECK TESTER, that could work to determine if there was some signal activity on a port. The only problem would be if the amount of data being written to the port was small, you might need a slow motion video to detect the LEDs blinking.

  9. #19
    Join Date
    Jan 2019
    Location
    Vancouver, BC or San Jose, California
    Posts
    31

    Default

    Sadly the machine is in Vancouver. I prefer to use the serial card because the problem with the cable that goes directly out of the CPU board is that there are so many things that I cant understand about it for example if you look at the board with a lot of serial ports, you can see that there are two empty 16 pin DIP sockets, that if you look at the ebay listing are connectors to two other connectors that I don't know where one goes, I do know that one of the connectors go to the CIO KBI card. Also there are +12 and ground connectors on the large board with many serial ports, and when I hooked up 12 volts to it, I fried a transistor.

  10. #20
    Join Date
    Jan 2019
    Location
    Vancouver, BC or San Jose, California
    Posts
    31

    Default

    Hey everyone, while I was waiting for an oscillocsope, I decided to check all the voltages again to make sure that they were in spec, and while checking the -15 and +15 volt line, it showed 30 volts. Is this normal?

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •