$400E/16398/CIA+14:      CIA Control Register A

   +-------+--------------------------------------------------------+
   | Bit 7 |   Unused                                               |
   | Bit 6 |   Serial Port ($400C) I/O Mode: 1 = Output, 0 = Input  |
   | Bit 5 |   Timer A Counts: 1 = CNT Signals, 0 = System 02 Clock |
   | Bit 4 |   Force Load Timer A: 1 = Now! (Write only Strobe Bit) |
   | Bit 3 |   Timer A Run Mode: 1 = One-Shot, 0 = Continuous       |
   | Bit 2 |   Timer A Output Mode to PB6: 1 = Toggle, 0 = Pulse    |
   | Bit 1 |   Timer A Output on PB6: 1 = Yes, 0 = No               |
   | Bit 0 |   Start/Stop Timer A: 1 = Start, 0 = Stop              |
   +-------+--------------------------------------------------------+

   Default Value: $x1/... (%0x000001)

ROM-Reference:

 LDA $400E  : $ACBD $ACDE $ADBB $ADD5 $DBD2
 STA $400E  : $ADC0 $ADDA $AF46 $DBC7 $DBD7 $DBDC $DBE0 $DBE5 $DBEA