The CD4057A is a 4 bit ALU Like cos/mos part (early cmos) for use in a LSI computers or control systems of its time and was produced by RCA. It boasted many features for parallelism, allowing for intelligently stacking multiple units together to create a wide range of bit depths. It varies somewhat from the 74181, in that it actually has an internal 4 bit shift register with which single bit shifts (across multiple devices). The shift register can be loaded via a function passed to the chip, and also acts as an internal results register on the falling edge of the clock cycle, making this chip kind of close to a 4-bit cousin of the Motorola MC145000 Industrial control unit.
In this project, I am attempting to build up a finite state machine in an EEPROM that pay's homage to this chip and tries to mimic it's functions.
using an EEPROM as a basis for the build, it is unlikely to clone the chip entirely. However, using a 4bit latch it may be possible to build many of the chips functions as A FSM (Finite State Machine).
The proof of concept will be a reduced instruction set chip with only 12 input pins. The test set up will consist of 2 eeproms (a low word and a high word),
two 4 bit d-latches (updating on the falling edge) a pair of 74hc194 parallel shift registers , a ram chip (or another eeprom) to feed code into the ALU a very simple clock circuit and some led's to display the output.
Love to see old devices brought back to life! I wonder if the equivalent function would fit into a GAL22V10...