
RS232 Option Installation Instructions for the 6500      02/17/92
Real-Time Hearing Aid Analyzer                               -med     

1. Check to make sure your upgrade kit contains the following:

   - UART chip
   - 1 or 2 EPROM chips 
   - 25-pin diagnostic plug
   - Floppy disk containing sample programs
   - Replacement internal ribbon cable with 25-pin connector
   - External RS232 cable to connect 6500 to computer
   - RS232 Troubleshooting Guidelines

2. Remove the wraparound cover from the instrument

   a. Unplug the power cord from the instrument.
   b. Turn the instrument on its side and remove the four screws       
       securing the wraparound to the bottom of the instrument. 
   c. Place the instrument upright again (on its feet).
   d. Peel the wraparound cover off the instrument by gripping 
       the bottom edge of the cover on either side of the 
       instrument, pulling it outward to flex the cover away from 
       the side of the chassis, then lifting up until the bottom 
       edge of the cover clears the top of the chassis. 

3. Install the UART chip and change jumper on the I/O board

   a. To install the new UART chip you must remove the I/O board 
      from the 6500.  To do this, first disconnect the buss 
      ribbon cable from the top edge of the I/O board and 
      as many adjacent boards as needed to be able to pull the 
      I/O board out of its bottom edge connector. If it is 
      necessary to remove any other connectors in order to remove 
      the I/O board, be sure to note the positions of the 
      connectors so that you will be able to properly reconnect 
      them.  Try to handle the board by its edges and avoid 
      touching components on the board.

   b. Install the 8250A or 16450 UART chip (the 40-pin IC that 
      was provided) into the UART socket located near the back 
      edge of the I/O board.  Try to avoid touching the pins of 
      the IC when handling it.  The index notch on the chip 
      should be pointing toward the top of the I/O board when it             
      is properly installed.  Make sure that none of the legs of 
      the IC are bent under or sticking out of the socket. 

   c. Move the jumper next to the UART (see Figure 2) so that it 
      connects the two pins oriented perpendicular to the UART.  

      Note: On older I/O boards, a plated run on the back of the 
       board connects the two jumper pins that are oriented 
       parallel to the UART. Cut the run between the pins if it 
       exists.
          
   d. Replace the I/O board in the bottom bus connector.  Replace 
      any other connectors which were removed, but do not replace 
      the top buss cable -- this will be replaced after 
      installing the EPROM(s).

4. Install the internal RS232 cable 
      (or replace it on older instruments)
   
   a. On newer instruments, a blank cover is installed where the 
      RS232 connector goes. To remove the cover, use a pair of 
      pliers to break off the studs holding the cover in place. 
      If the clips are still attached to the studs, use the 
      pliers to pull the clips off. Discard the old cover and 
      clips. Skip to item "d." below to finish the installation.

   b. Some older instrument have an internal RS232 cable which 
      will not work correctly with standard external RS232 
      cabling.  On these intruments it is necessary to replace 
      this cabling.

      To determine if your instrument has the older style 
      cabling, look inside the instrument at the wires connected 
      to the 25-pin connector labeled as "RS-232 COMPUTER 
      INTERFACE" on the back panel. If there is a brown wire 
      running from pin 7 (about in the middle) of the 25-pin 
      connector connector to the 7-pin connector on the       
      Input/Output circuit board (follow the ribbon cable to       
      locate the board), then this is an older style cable and it 
      needs to be replaced.  If the wire on pin 7 is connected to       
      a solder lug on the connector mounting screw (on the back       
      panel), the cable does not need to be replaced. 

      Note:  In some instruments, there is a wire connecting pin 
      1 of the 25-pin connector to the chassis.  This should not 
      be confused with the wire going to pin 7. 

   c. To remove the old style cable, first disconnect the 7-pin 
      connector from the I/O board.  Then remove the nuts 
      securing the 25-pin connector to the back panel and remove 
      the 25-pin connector from the instrument.  If there is a 
      wire connecting pin 1 of this connector to the grounding 
      lug on the chassis, the wire will need to be removed as 
      well in order to remove the connector.  Do not remove the 
      grounding lug from the instrument, and do not cut the 
      capacitor that is attached between the Video Monitor jack 
      and the grounding lug.  You may discard the old cable and 
      connector once they are removed. 

   d. To install the new cable, first fasten the new 25-pin 
      connector to the back panel using the jackscrews and nuts 
      provided.  Be sure to properly attach the grounding lug to 
      the connector mount screw to ensure a good connection.  On 
      older instruments, also make sure that the grounding lug 
      that attaches the capacitor from the Video Monitor jack is 
      firmly connected with the mount screw.  Next, connect the 
      7-pin connector to the I/O board so that the white dot on 
      the connector is oriented toward the bottom of the board.  
      This will place the gray wire of the ribbon cable toward 
      the top of the I/O board. 
 
5. Install the EPROM chip(s) in the CPU board

   a. Remove the CPU board from the 6500.  This board has no 
      cables connected to it (other than the top buss cable) and 
      has etched nomenclature saying "6500 CPU".  The EPROM 
      chip(s) are located in sockets along the front edge of the 
      board. Remove both the chip(s) from the sockets.  Install 
      the new EPROM chip(s) into the sockets.  If there are two 
      chips, they will be labeled #1 and #2.  The chip labeled #1 
      goes into the socket nearest the bottom of the board. The 
      notch on the EPROM should be oriented toward top of the 
      board when properly installed.  It is important to double 
      check this since installing the EPROMs backwards will 
      destroy them if you apply power to the instrument.  

   b. Reinstall the CPU board back in the instrument and replace 
      the top buss connectors on all system boards.  Make sure 
      the buss connectors are firmly in place on the edge 
      connectors of each circuit board.


6. Replace the wraparound cover on the instrument and the four 
    bottom screws.  The wraparound is most easily replaced by 
    fitting it squarely on top of the module, flexing each edge 
    separately and slide it down until it snaps into place.  

7. Test the RS232 installation using the diagnostic plug

   a. Make sure the instrument power is off.

   b. Insert the 25-pin test plug (included with the option kit) 
      into the 25-pin connector labeled "RS-232 Computer 
      Interface" on the back of the instrument. 

   c. Turn on the instrument.  The diagnostic tests are run 
      automatically on power up.  The instrument will display one 
      of the following messages on the opening display screen, 
      under the Frye Electronics copyright notice.

      RS-232 AVAILABLE -- Indicates that the RS232 option is 
       installed and the diagnostics were not run.  If this         
       message is displayed with the diagnostic plug installed,         
       the 7-pin connector may be misaligned on the pins on the         
       I/O board or not connected.

      DIAGNOSTICS PASSED -- Indicates that no problems were 
       detected in the RS232 operation.

      UART FAILED -- Indicates a bad UART chip was detected.  
       Check to make sure the UART is oriented properly on the 
       I/O board and that no pins bent under or sticking out of 
       the socket.  This message will also occur if an incorrect 
       UART is used, such as an 8250 (rather than 8250A).  Check 
       the UART nomenclature to verify that it is an 8250A or 
       16450 UART chip.

      NO INTERRUPT -- Indicates that the jumper next to the UART 
       is connected incorrectly or that the run between the 
       jumper pins parallel to the UART on the back of the board 
       is still intact.  

      BAD CABLE -- Indicates that the 7-pin connector on the I/O 
       board is installed upside down.  If the gray wire is 
       toward the top of the instrument and you still get this 
       message, a connection to the 25-pin connector may be bad.

   d. Remove the diagnostic plug for normal operation.  The 
       message line should say "RS-232 AVAILABLE" on startup 
       without the plug.

8. Return the EPROMs that were removed from the CPU board to 
    Frye Electronics, Inc. in the mailing box provided.


History: 04/03/92 -odo  
         10/19/92 -med  
         02/17/98 -med
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