take a .asm file and return machine language code.

take a set of .jack files and return machine language code .

primitive, uses builtin go.

rest is not primitive, derives from Nand.

barrel shifter, does a circular left shift of size n a right shift is just a 16-n left shift if you want a logical shift, mask the input beforehand.

take a set of .vm files and return a single .asm file.

This CPU also supports the leftshift operation if instr[2]==0, we ignore ALU output and use barrelshift out instead the first bit after instr[2] (so the a bit in the Hack spec) the a bit still switches A/M, the next bit toggles that or using D as input to shift and the next 4 bits encode how much to shift.

rest is not primitive, derives from DFF.

components: registers A and D, ALU, counter instr decoding, instr execution, next instr fetching.

primitive, uses builtin go.

Hacking the unused instruction bits to support more efficient ROM reading: adds a PC register that can be used to jump back and forth We store the pc output in this register by default instr bit 1 set to 0 disables this update so the value grows stale; next instruction now is read into A without executing and jumps back to where we came from.

Lets leave this one for posterity (ie old asm files) but I misunderstood the default screen dimensions :).

NOTE: no way to write to keyboard register.

writes values from an input file to a specific register Load clears the register and signals to read the next character -> so writing to this register sets it to 0 instead.

reads values to write to an output file or stdout sets the register to 0 when it is _done_ writing a character.