DOSVEC_lo       := $000A       ; 10 PROGRAM RUN VECTOR
DOSVEC_hi       := $000B
SDMCTL          := $022F       ; 559 DMACTL SHADOW
SHFLOC          := $02BE       ; 702
MEMTOP_lo       := $02E5       ; 741 END OF FREE RAM
MEMTOP_hi       := $02E6
ICCOM           := $0342       ; 834 ; Command byte (see C_* constants) (set by user)
ICBAL           := $0344       ; 836 ; Buffer address, LSB (set by user)
ICBAH           := $0345       ; 837 ; Buffer address, MSB (set by user)
ICBLL           := $0348       ; 840 ; Buffer length, LSB (set by user)
ICBLH           := $0349       ; 841 ; Buffer length, MSB (set by user)
ICAX1           := $034A       ; 842 ; AUX1 byte (2nd param in BASIC OPEN) (set by user)
ICAX2           := $034B       ; 843 ; AUX2 byte (4rd param in BASIC OPEN) (set by user)
BOOTRG          := $0700       ; 1792 PROGRAM AREA
CIOV            := $E456       ; 58454 ; Main CIO entry point!