Building FPGA board for a PDP/8 implementation

DISCOVERED INTERESTING FPGA BASED PDP-8 HARDWARE REPLICA

This design implements the hardware logic from a PDP-8 inside a single FPGA, something similar to how I recreated an IBM 1130 into a gate for gate cycle accurate replica using an FPGA. It runs on a Cyclone IV FPGA board that is plugged into a host board implementing memory, USB and some I/O connections. 

The host board from Land Boards is a RETRO-EP4CE15 board, which I bought on Tindie. It has a QMTech EP4CE15 FPGA board plugged into it. The bill of materials was easy to source on Mouser other than one voltage regulator chip which was obsolete/unavailable but for which plug compatible replacements exist. 

Assembling it brought a minor frustration - the silkscreen on the host board has no indication of orientation for the SRAM and USB chips, nor does the assembly instructions. I had to refer to the schematic and beep out the pads to determine which way to place those chips. 



The resolution of the pictures (and contrast) is inadequate to spot any chip markings that would help me place the part properly. 

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