Should resistors go at Vcc and Inputs of logic IC's to limit current ?

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PauloConstantino

Joined Jun 23, 2016
266
Hey, I built a CPU too as part of a course with two other partners. It was what we decided to do for our project. Late 70's. It wasn't particular fast, but it could sort numbers in ascending or decending order depending on the microcode that we devised. The code space as 16 words x 16 bits and the data space 16 x 4 bits. Breadboarded. We each took a section: memory, the microcoded instructions, and the program counter (me).

That's cool. I have seen many people building 16 byte/word machines. There's a SAP architecture that many people like to build. That's too simple for me. If I'm going to spend the time, it will have to be a proper CPU. I have designed a16bit accumulator/index type machine with 64K words. Many people tend to think that designing and building a CPU is an extreme feat. But when you get down to it you realize it's very simple. Again the only thing that bugs me down are some unexpected bugs related to cheap breadboards.

Yes I have taken propagation delays into account, otherwise there's no way to predict the speed of the machine...

I have also seen a guy build a full CPU in a giant breadboard and it worked. That's why I decided to try a breadboard CPU. If it worked for him it will have to work for me. I will change plans and go for better quality boards...

How much astray capacitance/inductance do "Cheap" chinese breadboards carry could anyone tell me ?
 

MrChips

Joined Oct 2, 2009
31,087
I don't know what you're on about. I can build this CPU in 1 month. Not only that, it's a 16bit CPU. I am a computer scientist. The only thing that might prevent me are some technicalities about electronics since I don't have much experience with electronics but this can be overcome.

I get really angry at comments like yours. I "start " with whatever I want to start with. You don't even know me, don't underestimate people you don't know.

A CPU is just a finite state machine. I have it all worked out.
Fine then. Have it your way.
I'll check back in twenty years and see how you're making out.
 

crutschow

Joined Mar 14, 2008
34,842
I don't know what you're on about. I can build this CPU in 1 month. Not only that, it's a 16bit CPU. I am a computer scientist. The only thing that might prevent me are some technicalities about electronics since I don't have much experience with electronics but this can be overcome.
.............
Yeah. A couple years of study and a couple years of experience may "overcome" those "technicalities about electronics". :rolleyes:
 
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