Description
The CDP1871A is a keyboard encoder designed to directly interface between a CDP1800-series microprocessor and a mechanical keyboard array, providing up to 53 ASCII coded keys and 32 HEX coded keys, as shown in the system diagram (Figure 1).

FEATUREs
• Directly Interfaces with CDP1800-Series Microprocessor
• Low Power Dissipation
• Three-State Outputs
• Scans and Generates Code for 53 Key ASCII Keyboard Plus 32 HEX Keys (SPST Mechanical Contact Switches)
• Shift, Control, and Alpha Lock Input
• RC-Controlled Debounce Circuitry
• Single Supply 4V to 10.5V. . . . . . . . . . . . . (CDP1871A)
    4V to 6.5V . . . . . . . . . . . . . (CDP1871AC)
• N-Key Lockout