+CIA1_PRA := $DC00 ; Port A
+CIA1_PRB := $DC01 ; Port B
+CIA1_DDRA := $DC02 ; Data direction register for port A
+CIA1_DDRB := $DC03 ; Data direction register for port B
+CIA1_TA := $DC04 ; 16-bit timer A
+CIA1_TB := $DC06 ; 16-bit timer B
+CIA1_TOD10 := $DC08 ; Time-of-day tenths of a second
+CIA1_TODSEC := $DC09 ; Time-of-day seconds
+CIA1_TODMIN := $DC0A ; Time-of-day minutes
+CIA1_TODHR := $DC0B ; Time-of-day hours
+CIA1_SDR := $DC0C ; Serial data register
+CIA1_ICR := $DC0D ; Interrupt control register
+CIA1_CRA := $DC0E ; Control register for timer A
+CIA1_CRB := $DC0F ; Control register for timer B