4 ms·
PDP-11/hack with some variations
- JPLeRouzic 2y agoThe original PDP-11/Hack was an attempt at designing a minimal PDP-11 based on a discarded J-11. The J-11 is a microprocessor a bit similar to a 16-bit M68000 or a fast I8086. http://madrona.ca/e/pdp11hack/index.html http://madrona.ca/e/pdp11hack/index.html Since that time, many people have made variations on Brent Hilpert design. One of my sources of inspiration is: https://www.5volts.ch/pages/pdp11hack/ https://www.5volts.ch/pages/pdp11hack/ My design has the following features, but I never instantiated it: * Much more RAM, 512KW * The data bus is buffered (it is not in other designs) * It has a GPIO (65C22) (because why not?) * It can write into the upper byte * The UART is the 6402, as in Brent Hilpert schematics, but the address is fully decoded to enable using a DEC OS. * It has 5 switches to test/learn to single-step the memory accesses, the HALT, interrupts, or make a reset * The boot configuration could be set up with micro-switches