Editing CDC 6600 (section)

====Central Processor access====
In addition to a conventional instruction set, the PPs have several instructions specifically intended to communicate with the central processor.<ref name=6000Ref />{{rp|pp.4-24–4-27}}
* <code>CRD d</code> - transfers one 60-bit word from central memory at the address specified by the PPs ''A'' register to five consecutive PP words beginning at address ''d''.
* <code>CRM d,m</code> - similar to CRD, but transfers a block of words whose length was previously stored at location ''d'' into PP memory starting at PP address ''m''.
* <code>CWD d</code> - assembles five consecutive PP words beginning at location ''d'', and transfers them to the central memory location specified by register ''A''.
* <code>CWM d,m</code> - transfers a block starting at PP memory address ''m'' to central memory. The central memory address was stored in register ''A'', and the length was stored at location ''d'' prior to execution.
* <code>RPN</code> - transfers the contents of the central processor's program address register to the PP's ''A'' register.
* <code>EXN</code> - ''Exchange Jump'' transmits an address from the ''A'' register and tells the processor to perform an ''Exchange Jump'' using the address specified. The CP Exchange Jump interrupts the processor, loads its registers from the specified location and stores the previous contents at the same location. This performs a task switch.<ref name="6000Ref">{{cite book |last1=Control Data Corporation |title=Control Data® 6000 Series Computer Systems Reference Manual |date=1965 |url=http://bitsavers.org/pdf/cdc/Tom_Hunter_Scans/6000_Series_Computer_Systems_RefMan_Jul65.pdf |access-date=March 28, 2023}}</ref>{{rp|pp.3-9–3-10}}