The Microchip Technology Inc. 23A512/23LC512 are 512 Kbit Serial SRAM devices. The memory is accessed via a simple Serial Peripheral Interface (SPI) compatible serial bus. The bus signals required are a clock input (SCK) plus separate data in (SI) and data out (SO) lines. Access to the device is controlled through a Chip Select (CS) input. Additionally, SDI (Serial Dual Interface) and SQI (Serial Quad Interface) is supported if your application needs faster data rates. This device also supports unlimited reads and writes to the memory array. The 23A512/23LC512 is available in standard packages including 8-lead SOIC, PDIP and 8-lead TSSOP.
“Building a homebrew CPU from scratch takes a large number of logic chips. It is understandable, that implementing registers, program counter, ALU, and other components of the CPU in TTL or CMOS logic does require a substantial amount of chips …
“This is another retro compute project. Use an Arduino Mega256, 64kB serial RAM, a display and a keypad to build a standalone computer. The idea I had the idea to build a standalone computer resembling the old ZX81 computer when …