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Assembled the ALU

A project log for 4 bit TTL ALU

Alternative for the 74LS181 ALU, built in One Square Inch

roelhroelh 08/30/2018 at 20:045 Comments

Yesterday evening the pcb's arrived...  I did send the gerbers only 5 days ago to China....  Now here I have 10 pcb's for only 15 Euro, with free shipment... unbelievable....

So I assembled one:

It is nice to see this 4-bit ALU next to the 8-bit relay-ALU from the RISC Relay CPU :

This is not completely fair, because the relay ALU has more functions:

But the Relay ALU can not do subtraction. It can subtract because the registers can deliver inverted bits.

The next step will be, to check or demonstrate the operation of the ALU. I will have to build a small demo setup.

Discussions

Dave's Dev Lab wrote 08/30/2018 at 20:07 point

Nice looking design! I am looking forward to testing this out on some my 4-bit designs!

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roelh wrote 08/31/2018 at 18:50 point

It would be nice to see it used in a design. Shall I send you a bare pcb ?

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Dave's Dev Lab wrote 09/01/2018 at 00:25 point

thanks for the offer, but i already ordered some pcbs with the gerbers you posted. i'll be testing it with my DDL4-CPU project: https://hackaday.io/project/158510-ddl4-cpu

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roelh wrote 09/01/2018 at 07:37 point

I'm very pleased to see that you want to use it in your project, I can't wait !

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roelh wrote 11/05/2018 at 13:46 point

Hi Dave, have you received the ALU boards yet ? Did you build and test ?

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