Image Map Image Map
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 21

Thread: Help with fixing Commodore 2040 Dual Floppy drive

  1. #11
    Join Date
    Feb 2009
    Location
    Southern California, USA
    Posts
    3,129

    Default

    Slightly better test patterns would be 170 and 85. They are alternating bit patterns. 170 decimal = AA hex = 10101010 and 85 decimal = 55 hex = 01010101.

    Can you input from tape? I have a couple of small programs to test the IEEE bus.

  2. #12
    Join Date
    Oct 2020
    Location
    Discovery Bay, California
    Posts
    78

    Default

    Hi Dave_M,

    I tested again with 170 and 85. Both work fine. I do not have tape capability, however, if the programs are small, I don't mind typing them in.

    Thanks
    Mike

  3. #13
    Join Date
    Feb 2009
    Location
    Southern California, USA
    Posts
    3,129

    Default

    Quote Originally Posted by MikeP View Post
    Hi Dave_M,

    I tested again with 170 and 85. Both work fine. I do not have tape capability, however, if the programs are small, I don't mind typing them in.

    Thanks
    Mike
    Your data path seems OK so you may only need the IEEE control lines test. I'll post the listings for that test. You would need to type a few lines at a time for each control line.

  4. #14
    Join Date
    Feb 2009
    Location
    Southern California, USA
    Posts
    3,129

    Default

    488 control1.JPG

    488 control2.JPG

    488 control3.JPG

    DAV Test - lines 10-80 plus 400 and 500
    NRFD Test - lines 90 -160 plus 600 and 700
    NDAC Test - lines 170 - 240 plus 800 and 900
    ATN Test - lines 250 - 320- plus 1000
    Skip any remarks/comments to save typing
    Last edited by dave_m; January 25th, 2021 at 01:41 PM.

  5. #15
    Join Date
    Oct 2020
    Location
    Discovery Bay, California
    Posts
    78

    Default

    Hi Dave_M,

    Thanks for posting the listing. I typed the whole program and everything reported as OK

    Mike

  6. #16

    Default

    Just a thought but are the contacts on the edge connector clean and free from dirt or oxidation ?

    Andy

    Quote Originally Posted by MikeP View Post
    Hi Dave_M,

    Thanks for posting the listing. I typed the whole program and everything reported as OK

    Mike

  7. #17
    Join Date
    Oct 2020
    Location
    Discovery Bay, California
    Posts
    78

    Default

    Hi Andy,

    It does look a little worn, here is a photo. I'm sure it would benefit from cleaning. IEEE Connector.jpg

    What would be the best method to clean/deoxidize it?

    Thanks
    Mike

  8. #18
    Join Date
    Feb 2009
    Location
    Southern California, USA
    Posts
    3,129

    Default

    Quote Originally Posted by MikeP View Post

    What would be the best method to clean/deoxidize it?
    Use a good contact cleaner or if you have some pure isopropyl alcohol (95%) that may be OK. Don't forget to clean both sides of the edge connector. Do not use a ruby rubber eraser. Commodore used little gold to start with. Don't rub any more off...

  9. #19
    Join Date
    Feb 2009
    Location
    Southern California, USA
    Posts
    3,129

    Default

    If that does not help, there are separate pins from the drivers that go to the connector so it is possible that there is a bad transceiver signal at the connector. Repeat data bus test with 55/AA hex pattern and check with meter at the connector.

    Here is the wiring at the IEEE connector: http://www.zimmers.net/anonftp/pub/c...8032087-02.gif

  10. #20
    Join Date
    Oct 2020
    Location
    Discovery Bay, California
    Posts
    78

    Default

    Hi Guys,

    Last week, after I cleaned the contacts with isopropyl alcohol, the SD2PET worked for a moment and then stopped, so I thought maybe it really is caused by bad contacts. Cutting to the chase, I bought some Deoxit D5 and cleaned the connector again and the SD2PET works. So, I used the Deoxit to clean the contacts on the 2040 Floppy Unit and the contacts on the cable, popped in a Floppy and it works, I was able to run a Program called Aztlan Communications Master Program Suite.

    That was drive number 0, next step is figure out if drive number 1 works (time to break out the manual).

    Thanks for helping me to troubleshoot this. It is so cool to be able to save and load from a floppy.

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
  •