By no means doubt the price of a excellent trainer. Despite the fact that — or assume — the fabric being introduced, a excellent trainer can open your eyes to new techniques of taking a look at issues that can pay dividends you by no means anticipated.
That’s the sensation we were given whilst staring at [Ben Eater]’s newest video on construction a keyboard interface (embedded underneath) for his breadboard 6502 pc. At the face of it, getting a keyboard to speak to a pc will have to be a easy process. [Ben] had utilized by the outdated PS/2 keyboard or even constructed a wildly complicated circuit out of discrete shift sign up chips to visualise the knowledge being despatched by way of the keyboard. The video underneath continues that paintings, this time focusing on the use of the keyboard together with his 6502 breadboard pc.
After some instructive preliminaries on interrupt programming, [Ben] dives into the logic-level main points of teasing helpful alerts from the keyboard. His sign processing begins with some inverters and an RC community to show more than one clock pulses into one common sense point transition. Strolling via this circuit step-by-step used to be the truly attention-grabbing bit; even though that the solution is in the end going to be “Schmitt cause,” attending to that time used to be truly instructive.
In fact, what [Ben]’s movies principally accomplish is making us need to practice along side him and construct a breadboard pc of our personal. From (*3*)a low-rez VGA card to, following along side his discrete chip builds is at all times instructional.