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A project log for JACA 1 & 2 Homebrew Computer

JACA - Just Another CPU Again Homebrew CPU, starting by a simple POC 4-bit CPU on circuit simulator soft. (done), then 8-bit (in progress)

andre-baptistaAndre Baptista 10/03/2017 at 20:090 Comments

Last two weeks saw some progress although not the expected.

In the Logisim realm, finally implemented the RET_ADDR register, which, unsurprisingly, stores the return address to be used in the CALL isntructions.

In the breadboards realm, I managed to build the IR (Instruction register), and a (small) part of the registers control logic.

In the "future steps" realm I studied and I am very optimistic about VGA output (maybe 256 x 240 pixels, 256 colors/pixel) and interfacing a regular PS/2 keyboard for input.

That's all people. See you next time.

Instruction register (IR) with 3 chips (each 8 bits) to hold a 24 bit instruction.

IR completed.

Registers logic very far from completed, with those ugly stickrs to help me remember what each wire is for.

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