UPI-41AH 42AH UNIVERSAL PERIPHERAL INTERFACE 8-BIT.
Intel
8741AH - Universal Peripheral Interface 8-Bit Slave Microcontroller
UPI-41AH 42AH UNIVERSAL PERIPHERAL INTERFACE 8-BIT SLAVE MICROCONTROLLER Y Y UPI-41 6 MHz UPI-42 12 5 MHz Pin Software and Architecturally Compatible.