GWKB1023 : Serial Synthesizer Not Working

Product: Window-Eyes
Author: Aaron Smith
Date Added: 09/22/2005
Last Modified: 09/22/2005

Symptom: Serial synthesizer, such as the DECtalk Express, are either not detected by Window-Eyes, or are not speaking correctly, such as random characters.

Cause: There is a communication problem between the operating system, and the serial synthesizer.

Solution: You will need to turn off FIFO buffers. The steps for disabling this feature under Windows XP are as follows:

  1. Press WINDOWS-BREAK to open the System Properties control (You can also access this control panel through the Windows control panel item in the start menu)
  2. Arrow right to the Hardware tab
  3. TAB to the Device Manager, and press ENTER
  4. Press TAB to access the Device Manager tree view
  5. Press P to select the Ports (COM & LPT) option
  6. Press RIGHT ARROW to expand the Ports (COM & LPT) option
  7. ARROW DOWN to select the com port where your serial synthesizer is connected
  8. Press SHIFT-F10 to bring up the context menu
  9. Press R to access the properties dialog
  10. Press CTRL-TAB once to access the Port Settings tab control
  11. Press ALT-A to open the Advanced Settings dialog
  12. Press SPACE BAR to uncheck the Use FIFO buffers check box
  13. Press ENTER to close the Advanced Settings dialog
  14. Press ALT-F4 to close the properties dialog
  15. Press ALT-F4 to close the Device Manager

Windows 9x/ME users who also use MS-DOS boxes along with MS-DOS screen readers may also need to add the line

comXautoassign=0 (Where X is the number of the com port where the serial synthesizer is connected)

to the system.ini file, located in the windows directory, and then reboot.