The PIC32 Minimalist Equivalent
As a mark to this colossal machine and to Unix, I decided to construct a working computer
capable of running BSD in similar fashion to the 11/780 in a rather more manageable size. Luckily technology has
moved on somewhat since the 1970s, and the challenges facing the DEC hardware engineers back then are no longer
relevant to the casual constructor. Thanks to the work done by Serge Vakulenko, the developer responsible for
porting one of the final versions 4.4BSD-Lite over to the Microchip PIC32MZ, and the fact that the PIC32
microcontroller uses the MIPS instruction set, running native BSD Unix code on this single chip is certainly
possible. The amazing PIC32MZ2048ECM064 microcontroller has built in 2MB of flash memory used to store the kernel,
512kB of memory managed RAM to give 4GB of addressable memory space necessary to run a multi-user / multi-tasking
operating system such as BSD.
You may be thinking 'well I can do the same thing on my Raspberry Pi'. You're right you can, but the difference is
that the Pi uses the SIMH system emulator to translate instructions and does not actually run native Unix code, and
so will run with degraded performance.
As a basic computer with just one serial terminal port fitted and without the optional Ethernet, the circuit diagram
is surprisingly sparse and simple.