I only saw the one error that had already been pointed out by another commmenter in this video. Now I'll cover set/reset logic for a single-relay latch. Set is accomplished by having a normally open switch that energizes the coil when pressed, similar to the two-relay version. Reset is accomplished by having the loopback go through a normally _closed_ switch, which disconnects the output of the buffer from the input when pressed. This is part of why it's not great for teaching how latches work, since "disconnected" isn't necessarily equivalent to "off" for all devices.
Correct, I’ll be covering a single relay latch when I build the register bank. I’m planning to use Deiter Muller’s ALU design as well which is pretty cool (5 relays per bit). I test these videos on my daughters and I stop when they start to look bored.
Mister Matt, there is any web applications to test these circuits? What one do you recommend? As a Computer Architecture student, practice always helps
I have never seen an SR latch described as a sequence of gates before. It made its functioning much more intuitive. Also, I see you are using 12 volt relays. I purchased 5 volt ones, and in the 6502 forum someone said 12 volts are preferred due to current considerations. Any thoughts on this?
Thanks Martin. I think you’re probably going to need a transistor to drive the relay when interfacing with conventional logic, so think there isn’t a huge difference between 5v and 12v. I’ve got a simulation of the relay based sequencer/decoder running, it’s about 300 relays, so I used 12v ones because they were a bit more common and cheaper!
I have never seen it before using relays. Opens up the mind to a whole set of possibilities. Thank you!
Enjoy!
I only saw the one error that had already been pointed out by another commmenter in this video.
Now I'll cover set/reset logic for a single-relay latch. Set is accomplished by having a normally open switch that energizes the coil when pressed, similar to the two-relay version. Reset is accomplished by having the loopback go through a normally _closed_ switch, which disconnects the output of the buffer from the input when pressed. This is part of why it's not great for teaching how latches work, since "disconnected" isn't necessarily equivalent to "off" for all devices.
Correct, I’ll be covering a single relay latch when I build the register bank. I’m planning to use Deiter Muller’s ALU design as well which is pretty cool (5 relays per bit). I test these videos on my daughters and I stop when they start to look bored.
@@DrMattRegan Good testing strategy.
Mister Matt, there is any web applications to test these circuits? What one do you recommend? As a Computer Architecture student, practice always helps
Hmmm. I haven’t really used one. I tend to simulate things in C++. Someone else watching may be able to advise better.
Oops in the truth table at 7:28
Darn it. I thought I corrected that. I’ll make a note in the next video. The third line should read 1 0 not 1 1.
@@DrMattRegan That's always the way. Back in the day of printing something and then finding a typo. Especially when back in the day was a dot matrix.
I have never seen an SR latch described as a sequence of gates before. It made its functioning much more intuitive. Also, I see you are using 12 volt relays. I purchased 5 volt ones, and in the 6502 forum someone said 12 volts are preferred due to current considerations. Any thoughts on this?
Thanks Martin. I think you’re probably going to need a transistor to drive the relay when interfacing with conventional logic, so think there isn’t a huge difference between 5v and 12v. I’ve got a simulation of the relay based sequencer/decoder running, it’s about 300 relays, so I used 12v ones because they were a bit more common and cheaper!
@@DrMattRegan OK thanks. Neil in the forum posted a link to a source of 12 volt relays that's $0.50 per relay, so I can always buy more.