> An EPROM is probably the most widely used example of a PLD.
Upvote for this. When I used to think about PROM, I think it as a medium of data storage, or sometimes think it's a lookup table. But it's actually simplest form of programmable logic device - a device that can transform x-bit of arbitrary input signals to y-bit of arbitrary output signals, so you can build any digital system that uses combinational logic in PROM (and RAM for sequential logic), including a CPU. And since it's a PROM, you can reprogram it to implement another different logic device, simply by burning a new truth table.
After I realized this, the existence of reprogrammable hardware like FPGAs no longer sounds like magic to me anymore. From this, you can also see that computers with finite RAM and ROM is not a Turing machine, but a Finite State Machine.
Upvote for this. When I used to think about PROM, I think it as a medium of data storage, or sometimes think it's a lookup table. But it's actually simplest form of programmable logic device - a device that can transform x-bit of arbitrary input signals to y-bit of arbitrary output signals, so you can build any digital system that uses combinational logic in PROM (and RAM for sequential logic), including a CPU. And since it's a PROM, you can reprogram it to implement another different logic device, simply by burning a new truth table.
After I realized this, the existence of reprogrammable hardware like FPGAs no longer sounds like magic to me anymore. From this, you can also see that computers with finite RAM and ROM is not a Turing machine, but a Finite State Machine.