Combinational Hex Multiplication

[Legofreak]

About a year ago I made a sequential hex multiplier. It could only multiply 2 one digit hex numbers together. For a very long time I have pondered how to do more than just one digit.

Now I have made a breakthrough.

I present my combinational hex multiplier.

At first I just made a combinational multiplier for a 2 single digit hex numbers. Then I stacked it in an offset 4x4 grid in order to cross multiply. After it multiplies all the combinations, it adds up all the small products into the final product. It's hella slow, but the numbers go pretty high... it goes up to FFFE0001, which is 4,294,836,225 in decimal. this is equivalent to multiplying two 16-digit binary numbers.

Anyway... here are some pictures...

8 digit display (2222*2222=48D0C84)


Each input is connected to 4 multipliers in a cross pattern


Really big and slow...


outputs from the multipliers were grouped by denomination in order to be added together.


Didn't bother remaking the adder to 4 different sizes so I just copied the same one 7 times. The carry runs at the end below the whole thing.

[Legofreak]

here's the picture i made to help me figure out how to add up the partial products. kinda hard to see it when not full size...

[TuchiTheSalt]

pretty awesome but how many ticks is this beast

[Legofreak]

I havent even counted :X i didnt bother optimizing any of it...

I'm gonna guess about 150 ticks... ew right? lol

[Apocryphan]

I usually don't make it to the end before I end up upgrading or scrapping parts, I swear Im on my 5th calculator and have yet to make an actual control center and display for it.

[Legofreak]

I reuse the same 7 segment display a lot. Just copy and slap it on whatever I'm working on. Its like a ohm meter for analog. It's 5 wide stackable but here it's stacked at 8 blocks.

[Apocryphan]

Ive wired them before but ive been trying to make a small/fast one to match the size and speed of my adder, but i havent dedicated alot of time to it, i try to improve/invent 3 pieces a day, so if i get stuck on an idea, I'll leave it for a day and try it again with new eyes. Often ill see "the missing link" while im working on a completely different circuit.

Which reminds me i need to add the 5 things i made yesterday to my word processor post. Some things are just compacting or implementing better ways. And some are just trying different methods like serial bussing.

[LordDecapo]

I have an infographic on this type of multiplication if you want it.. I will just have to grab it from my computer later, don't think I have it on this phone