---

CAS50 protocol – Serial protocol used by calculators from 1996 to 2004

The CAS50 is an evolution of the CAS40 protocol for CASIO calculators from 1996 to 2004, excluding AFX / Graph 100 and Classpad 300 / 330 (+) models which have their own protocol variations.

Note

The term was coined by Thomas Touhey, as an evolution of CAS40 with 50, the size of the headers in the variant, in bytes.

This protocol is usually present over Serial transport. Serial settings are always the same, and do not vary during the transfer:

• Speed: 9600 bauds.

• Parity: none.

• Stop bits: 2.

See the following sections for more details regarding the protocol.

• CAS50 packet format
  • 0x13 – Established packet
  • 0x15 – Abort
  • 0x16 – Start packet
  • 0x21 – Overwrite confirmation request
  • 0x24 – Invalid data type
  • 0x2B – Corrupted header
  • 0x3A – Header and data packet
  • 0x51 – Invalid header
• CAS50 data types
  • END\xFF End
  • FNC\0 Function
  • IMG\0 Image
  • MEM\0 Memory Dump
  • REQ\0 Request
  • TXT\0 Textual File
  • VAL\0 Value
• CAS50 flows
  • Initiate the connection
  • Send or receive data
  • Request data using the CAS50 variant