Image Map Image Map
Page 9 of 9 FirstFirst ... 56789
Results 81 to 86 of 86

Thread: Project: Micro 8088 - Chipset-based 8088 XT compatible processor board

  1. #81

    Default FE2010A-JU Parts Available

    Quote Originally Posted by Valerio View Post
    Given that the FE2010 is hard to find, could the C&T 82c100 be a suitable alternative?
    just fyi, i have some FE2010A-JU parts available on ebay:

    https://www.ebay.com/itm/Western-Dig...p/254307837960

  2. #82

    Default

    For a while now I am having a problem with this board.

    With configuration 74F00 (U14) segments E0000 and F0000 are duplicated. Boot fine because the duplicate BIOS is in FA000 but there is an exact copy in EA000. This configuration is not a problem since it is a segment that you would not use.

    With the SPLD configuration ATF16V8B (U16) I always observe the segment E000 with FFs ... regardless of the state of switch 3.5 to make use of that segment as UMB. With this configuration, DOSMAX cannot be used until EFFF because it hangs, it can only be used up to DFFF ... therefore segment E0000 is unusable.

    I have checked pins 6 and 15 of 74F573 (U9), I have tried to replace it with other ICs, I have also replaced U7 and U8. I've also tried changing the FLASH memory and the two RAM ICs ... I've also tried replacing the Faraday FE2010A with another.

    Any idea where the problem may be? Some time ago, after assembling the board, it worked fine but one day this segment stopped working.

  3. #83

    Default

    Quote Originally Posted by spark2k06 View Post
    For a while now I am having a problem with this board.

    With configuration 74F00 (U14) segments E0000 and F0000 are duplicated. Boot fine because the duplicate BIOS is in FA000 but there is an exact copy in EA000. This configuration is not a problem since it is a segment that you would not use.

    With the SPLD configuration ATF16V8B (U16) I always observe the segment E000 with FFs ... regardless of the state of switch 3.5 to make use of that segment as UMB. With this configuration, DOSMAX cannot be used until EFFF because it hangs, it can only be used up to DFFF ... therefore segment E0000 is unusable.

    I have checked pins 6 and 15 of 74F573 (U9), I have tried to replace it with other ICs, I have also replaced U7 and U8. I've also tried changing the FLASH memory and the two RAM ICs ... I've also tried replacing the Faraday FE2010A with another.

    Any idea where the problem may be? Some time ago, after assembling the board, it worked fine but one day this segment stopped working.
    Are you sure the SPLD is programmed with the correct configuration? The speaker still works with the SPLD?

  4. #84

    Default

    Quote Originally Posted by nztdm View Post
    Are you sure the SPLD is programmed with the correct configuration? The speaker still works with the SPLD?

    I will flash it again, but I would say yes ... the speaker works without any problem with the SPLD.

    However, what explanation is the duplication of content in E0000 and F0000 using 74F00 instead of SPLD?

  5. #85

    Default

    Quote Originally Posted by spark2k06 View Post
    I will flash it again, but I would say yes ... the speaker works without any problem with the SPLD.

    However, what explanation is the duplication of content in E0000 and F0000 using 74F00 instead of SPLD?
    Are JP3 and JP4 closed when using 74F00, and open when using SPLD?
    I can't think of anything else at present.

  6. #86

    Default

    Quote Originally Posted by nztdm View Post
    Are JP3 and JP4 closed when using 74F00, and open when using SPLD?
    I can't think of anything else at present.

    I've reflashed the SPLD and nothing, FFs in segment E0000 even with switch 3.5 on. Yes, when I change SPLD and 74F00 I also open and close JP3-JP4 accordingly.

    It's a mystery. Should it be associated with a pin of some IC that controls that segment of memory ... maybe a shortcircuit or a cold weld?
    However, I have checked pins 6 and 15 of 74F573 (U9) and they appear to be correct ... I will review it again when I have a while.


    Any other ideas are welcome.

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
  •