Feature 13 is provided to assist in resolving upper memory conflicts. The Feature 13 adjustment manually turns off auto scanning of upper memory blocks (UMB's) when installing Concurrent DOS. Sometimes there is a memory conflict with some add on I/O boards and some motherboard components (BIOS, chip set, etc.). The automatic memory scanning must be turned off manually by using the Feature 13 utility to allow the installation to succeed. This procedure is specific to Arnet boards addressed at D000, but can be used in general for other conflicts.

The main symptom or common problem requiring the use of this adjustment is that the computer will show an OP Code error during the INIT sequence usually at a memory address in the 1300 area. The installation will abort and stop. Follow the steps shown below to set up and use Feature 13.

  1. Boot to MS-DOS (Microsoft) - or other DOS
  2. Put your Concurrent DOS Startup disk in drive A (make sure the write protect is off)
  3. Make A the current disk drive (A:[enter])
  4. Type FEATURE 13 1 CCPM
  5. Push the reset button on the computer or press [Ctrl-Alt-Del] to reboot the computer. With CCI Startup Disk in drive A, the system should install properly at this time but with no UMB's used - follow screen instruction for installation and then reboot
  6. Make C the current drive
  7. Type FEATURE 13 0 CCPM -- This restores the original condition to CCPM
  8. Run SETUP from the root directory - your path should allow this - or type \CDOS\SETUP
  9. At the MAIN MENU press F4 then F10 to get to ENABLE HIGH MEMORY screen
  10. Press F5 three (3) times to be sure that ALL blocks on all pages have been disabled
  11. Escape to MAIN MENU, press F10, F5 to save this configuration in CCPM.SYS
  12. Be sure drive A has no floppy installed and reboot your system.
  13. At this point is it advised that you save this version of CCPM.SYS as CCPM.OK.
  14. Run SETUP, press F4 and F10 (see step 9)
  15. Press PageDown one time to view D000 page of memory
  16. Use F6 to enable each block, using the down arrow to move to the next block until all "D" blocks are enabled.  Note: DO NOT use F5 to enable all blocks as this will enable all blocks on all pages
  17. Escape to MAIN MENU, press F10, F5 to save this configuration in CCPM.SYS
  18. Be sure drive A has no floppy installed and reboot your system.
  19. At this point we recommend that you save this version of CCPM.SYS as CCPM.OK. This copy may save you some time, if you must fall back to it.
  20. Run SETUP, press F4 and F10 (see step 9)
  21. Press PageDown 2 times view E000 memory page (see also step 16 - use for E000 blocks)
  22. Use F6 to enable each block using the down arrow to move to the next block until all "E" blocks are enabled.
  23. Escape to MAIN MENU, press F10, F5 to save this configuration in CCPM.SYS.
  24. Be sure drive A has no floppy installed and reboot your system.
  25. At this point we advise again that you save this version of CCPM.SYS as CCPM.OK. This copy may save you some time, if you must fall back to it.

You should now have a working system. If any boot step fails, fall back to the previous CCPM file by renaming it (REN CCPM.OK CCPM.SYS). You may want to go back into the offending memory page and use the SETUP Enable Memory (step 4) and use a half splitting technique to enable as much memory as you can.