Curtis Keyer IC Pin-outs

     There are different pin-outs for each of the different 8044 
packages.  The 8044 and 8044B are 16-pin ICs and the 8044M and 
8044BM are 18 pin packages.  These are electrically equivalent, 
except that the 8044M/BM includes a sending speed function.  
There is also a new version of this IC available, the 8044ABM.  
If this is the chip you have, you will need to make a few changes 
to your keyer circuit.  Below is a table of the pin-outs of these 
ICs and the circuit changes necessary for the 8044ABM.

     Signal Name  8044/B 16-Pin  8044M/BM 18-Pin  8044ABM 20-Pin
     -----------  -------------  ---------------  --------------
     Vss (GND)           1              1              2
     Dot Key             2              2              3
     Rdot                3              3              4
     Cdot                4              4              5
     Cdash               5              5              6
     Rdash               6              6              7
     AB Select           -              -              8
     Dash Key            7              7              9
     Rspeed              8              8              10
     Cmeter              -              9              11
     Speed Meter         -              10             12
     RCspeed             9              11             13
     Cspeed              10             12             14
     Rpitch              11             13             15
     RCpitch             12             14             16
     Cpitch              13             15             17
     Keyed Output        14             16             18
     Wgt Select          -              -              19
     Manual Key, Wgt     15             17             20
     Vcc (+V, 5-10V)     16             18             1

     Note: To modify the keyer circuit in the ARRL Handbook for use
     with the 8044ABM, make the following changes:
 
     1. Add a 47k resistor in series with the connection to the
        RCspeed pin.
     2. For AB Select, ground the pin for A type iambic keying or
        connect it to Vcc for B type iambic keying.
     3. The Wgt Select pin should be grounded.


Technical Note: Type A and B Iambic keying.

With Type A keying, when both paddles have been pressed simultaneously, 
the last dot or dash being sent when the paddles are released is 
completed and nothing else is sent. (Example: hold down the dot paddle
then press the dash paddle, then quickly release both.  The result will
be dot, dash.)

With Type B keying, when both paddles have been pressed simultaneously, 
the last dot or dash being sent when the paddles are released is 
completed and an opposite element is also sent. (For the same paddle
presses above, this would result in a dot, dash, dot sequence).

Type B keying is preferred by some operators as a way of sending more 
code elements for less paddle presses, but the paddle press timing
becomes more critical for characters with short sequences (N, A, etc.)