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CAS40 protocol – Serial protocol used by pre-1996 calculators

The CAS40 variant of the CASIOLINK protocol is the earliest protocol used by CASIO calculators over serial links.

Note

The term was coined by Thomas Touhey, combining “CAS”, the start of “CASIOLINK” and also the name of the community tool from that time (see CaS command-line reference), and 40, the size in bytes of the headers used in the protocol.

This protocol is usually present over Serial transport. Serial settings are selected manually on both the sender and the receiver, and stay the same until the communication ends. Available serial settings on the reference implementations of this protocol are the following:

• Speed: 1200, 2400, 4800 or 9600 bauds.

• Parity: even, odd or none.

• Stop bits: 1.

See the following sections for more details regarding the protocol.

• CAS40 packet format
  • 0x06 – Acknowledge packet
  • 0x13 – Established packet
  • 0x16 – Start packet
  • 0x3A – Header and data packet
• CAS40 data types
  • \x17\x17 AL End
  • \x17\xFF End
  • A1 Dynamic Graph
  • AA Dynamic Graph in Bulk
  • AD All Variable Memories
  • AL All
  • AM Variable Memories
  • BU Backup
  • DC Color Screenshot
  • DD Monochrome Screenshot
  • DM Defined Memories
  • EN Single Editor Program
  • EP Single Password Protected Editor Program
  • F1 Single Function
  • F6 Multiple Functions
  • FN Single Editor Program in Bulk
  • FP Single Password Protected Editor Program in Bulk
  • G1 Graph Function
  • GA Graph Function in Bulk
  • GF Factor
  • GR Range
  • GT Function Table
  • M1 Single Matrix
  • MA Single Matrix in Bulk
  • P1 Single Numbered Program
  • PD Polynomial Equation
  • PZ Multiple Numbered Programs
  • RT Recursion Table
  • SD Simultaneous Equations
  • SR Paired Variable Data
  • SS Single Variable Data
• CAS40 flows
  • Initiate the connection
  • Send or receive data