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Tags: 8-bit

project.name
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ram rom selector

ram rom selector
These are example circuits targeted to 8-bits homebrew computers. They are simple circuits to select between ROM and RAM memories when they share partial block of address space, i.e. if you have a big ROM chip, let's say 32K but you won't use it every single cell of it. So you can set a ROM and a RAM chip on the same address space and set your computer to select the proper one.
Let me explain. Let's say that you have 1x 32K ROM chip and 2x 32K RAM chips and you're using a Z80. The Z80 needs ROM on the first page of the address space because at reset it points to $0000 address cell. But your firmware only occupies 16/18 KB of space. So you can build this RAM/ROM selector using simple chips from the 74xx series and let the computer switches between the 2 kinds of memory. In the first one, for example, the CPU reads from ROM chip up to address $4FFF (20,479), then reads/writes from/RAM. In the second one, the CPU addresses the ROM for the first 24K of memory then switches to RAM

project.name
3 Stars     859 Views
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SAP-1 ("Simple As Possible")

A simple 8-bit processor. It has a simple instruction set:
  • LDA - 0 - Load RAM data into accumulator
  • ADD - 1 - Add RAM data to accumulator
  • SUB - 2 - Subtract RAM data from accumulator
  • OUT - e - Load accumulator data into output register
  • HLT - f - Stop processing
Credits to the book "Digital Computer Electronics" by Albert Paul Mauvino, where he invented the educational processor.

project.name
1 Stars     170 Views

DED for 8-bit data using Hamming code

DED for 8-bit data using Hamming code

DED for 8-bit data using Hamming code


project.name
0 Stars     375 Views
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8B Addressable RAM

8B Addressable RAM

8 Bytes of addressable Memory. 3 Inputs top left are address, 8 inputs above flip-flops are data in, and button above data in is write. (Don't hurt me I'm new)


project.name
1 Stars     369 Views
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8-bit computer simplified v2

8-bit computer simplified v2

A computer made completely out of logic gates. Version 2. V1 can be found here: https://circuitverse.org/users/13948/projects/49969

Because of the limitations of the circuitverse.org simulator, and for easier use, some inbuilt components are used (like the 256-byte RAM module), but most of it is made up of OR, AND, NOT, XOR, NOR and NAND.

This project was originally made for my profile project. This is (or will be) version 2 of the 8-bit computer.


project.name
3 Stars     253 Views

I finally did it.
I made my own 8-bit CPU! With a bit of inspiration from other CircuitVerse projects and from a book called, Digital Computer Electronics.
The premade program does this: 12 + 6 - 3 + 2 (which equals 17)

program the computer by typing in the opcodes in the ROM

Opcodes: (X = address)
0X = Load X's value to Accumulator
1X = Add X's value to Accumulator
2x = Subtract X's value from Accumulator
ee = Take Accumulator's value and put it in the Output
ff = Halt/stop everything

Versions (Date format: DD/MM)
9/11 v1.0 - Finally finished it!


project.name
0 Stars     79 Views
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8-bit Adder

8-bit Adder

project.name
0 Stars     171 Views
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An 8-bit CPU with an instruction set that includes the analytic integration and differentiation of polynomial expressions.


project.name
0 Stars     67 Views

7-Bit BRWD

7-Bit BRWD

BRWD: BINARY READER AND WRITER DEVICE

Specs:

7-bit RAM

8-bit Memory

How to use:

1. To start writing, set your clock speed, and turn on the "Writer" switch.

2. To scroll through the memory, turn on the "Scroll" switch. Press "Reset" if you are ready to read.

3. Turn the "Writer" switch off, and turn on "Scroll" to start reading the binary.

4. Then when you're done, press "Reset RAM" to reset your writing.


project.name
0 Stars     69 Views

8-bit Microcomputer v1.9

8-bit Microcomputer v1.9

Under construction.


project.name
0 Stars     49 Views

8-bit Microcomputer v1.5

8-bit Microcomputer v1.5

Under construction.


project.name
1 Stars     161 Views

8-bit Microcomputer v2.0

8-bit Microcomputer v2.0

Under construction.


project.name
0 Stars     15 Views

Arquitectura Organizacional

Arquitectura Organizacional

project.name
0 Stars     23 Views
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Literally a whole computer

Literally a whole computer

Creating an entire functional and custom 8-bit computer from scratch with assembly language support (not yet complete)


project.name
1 Stars     16 Views
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Add/Subrtract

Add/Subrtract

Features a single-bit adder and subtractor as well as a combination of the two. Also showcases a 4-bit adder/subtractor and an 8-bit ALU adder subtractor.


(If anything in the description is wrong please feel free to say so in the comments.


project.name
1 Stars     48 Views
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FEMBOY-8

Functional Electronic Machine Binary Operator Yes

8-bit CPU

Working on a NEW CPU: Femboy-16!


ASSEMBLER:

https://output.jsbin.com/wutikij

GPU:

https://circuitverse.org/users/214464/projects/cb-ppu


INSTRUCTION SET:
00: NOP - Nothing
01: HLT - Halt program
02: OUT [id] - Output the accumulator out of an output
03: LDI A, [d8] - Loads immediate 8 bit word into the accumulator
04: MOV [r], A - Move register to accumulator
05: MOV A, [r] - Move accumulator to register
06: INC [r] - Increment a register
07: DEC [r] - Decrememt a register
08: ADD [r], A - Add the accumulator from a register
09: SUB [r], A - Subtract the accumulator from a register
0A: AND [r], A - And the register and accumulator
0B: IOR [r], A - OR the register and accumulator
0C: XOR [r], A - XOR the register and accumulator
0D: NOT [r] - NOT a register
0E: SRR [r] - Barrel shift accumulator right
0F: SRL [r] - Barrel shift accumulator left
10: JUP [d8] - Jump to a location
11: JPP [r] - Jump to a register value
12: JPL A, [d8] - Jump if accumulator is less than 0
13: JZO A, [d8] - Jump if accumulator is 0
14: JPG A, [d8] - Jump if accumulator is greater than 0
15: JLE A, [d8] - Jump if accumulator is less than or equal to 0
16: JGE A, [d8] Jump if accumulator is greater than or equal to 0
17: JNZ A, [d8] Jump if accumulator is not 0
18: CLR [r] - Clear a register
19: INP [id] - Store INPUT id in accumulator
1A: MOV pA, [r] - Move the value at address A register r
1B:  MOV [r], pA - Move register r into address A
1C: MOV [p], A - Move a value in a pointer to the accumulator
1D: MOV A, [p] - Move the accumulator to a location
1E: MLT [r], A - Multiply register r by the accumulator
1F: DIV [r], A - Divide register r by accumulator


REGISTERS:
00: REGISTER 1
01: REGISTER 2
02: REGISTER 3
04: REGISTER 4
05: ZERO FLAG (R)
06:
PC (R)
07: ALU Result (R)


Update Notes:

V4:
So this is the 4th iteration of my CPU lol... I added a few programs for you all to try out and you can even use an assembler now!

V5:
Long time since I updated this... But I've added a GPU! It's called "Color burst" and you can go try out some premade programs I have added on it! There's an assembler guide with GPU dev guide and I encourage you all to go try and make some graphical programs! Also more docs can be found on it's project page.


To-Do:
Increase amount of registers to 8
Make a simple command line
Make a simple operating system for the CPU


project.name
0 Stars     10 Views
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FEMBOY-8v1.1

FEMBOY-8v1.1

Functional Electronic Machine Binary Operator Yes - 8-bit cpu

This is a work in progress right now.


INSTRUCTION SET:
00:
MOV [r], A - Loads a register into the accumulator.
01: MOV A, [r] - Saves a register into the accumulator.
02: INC [r] - Increment a register 
03: DEC [r] - Decrement a register
04: ADD [r] - Add the accumulator to a register
05: SUB [r] - Subtract the accumulator to a register
06: OUT [r] - Output a signal from a register
07: HLT - End program


REGISTERS:
00:
REGISTER 1
01: REGISTER 2
02: REGISTER 3
04: REGISTER 4


Update Notes:
Final design before update of is a.


To-Do:
Add WIP instructions
Add the accumulator to a register address
Increase amount of registers to 8
Add Ram manipulation instructions
Add Input to CPU
Add more operations to the ALU
Add ASCII i/o
Make a simple command line
Make an assember
Make a simple operating system for the cpu
Add rgb output


project.name
1 Stars     12 Views
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Functional Electronic Machine Binary Operator Yes - 8-bit cpu

This is a work in progress right now.


INSTRUCTION SET:
00: NOP - Nothing
01: HLT - Halt program
02: OUT [r] - Output a register
03: LDA [d8] - Loads 8 bit data into the accumulator
04: MOV [r], A - Move register to accumulator
05: MOV A, [r] - Move accumulator to register
06: INC [r] - Increment a register
07: DEC [r] - Decrememt a register
08: ADD [r], A - Add the accumulator from a register
09: SUB [r], A - Subtract the accumulator from a register
0A: AND [r], A - And the register and accumulator
0B: IOR [r], A - OR the register and accumulator
0C: XOR [r], A - XOR the register and accumulator
0D: NOT [r] - NOT a register
0E: SRR [r] - Shift register right
0F: SRL [r] - Shift register Left


REGISTERS:
00: 
REGISTER 1
01: REGISTER 2
02: REGISTER 3
04: REGISTER 4


Update Notes:
The instruction set now has 16 instructions with logic operations, loading, shift, and nop. 


To-Do:
Add WIP instructions
Add the accumulator to a register address
Increase amount of registers to 8
Add Ram manipulation instructions
Add Input to CPU
Add more operations to the ALU
Add ASCII i/o
Make a simple command line
Make an assember
Make a simple operating system for the cpu
Add rgb output


project.name
0 Stars     8 Views
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Functional Electronic Machine Binary Operator Yes - 8-bit cpu

This is a work in progress right now.


INSTRUCTION SET:
00: NOP - Nothing
01: HLT - Halt program
02: OUT [id] - Output the accumulator out of an output
03: LDI A, [d8] - Loads immediate 8 bit word into the accumulator
04: MOV [r], A - Move register to accumulator
05: MOV A, [r] - Move accumulator to register
06: INC [r] - Increment a register
07: DEC [r] - Decrememt a register
08: ADD [r], A - Add the accumulator from a register
09: SUB [r], A - Subtract the accumulator from a register
0A: AND [r], A - And the register and accumulator
0B: IOR [r], A - OR the register and accumulator
0C: XOR [r], A - XOR the register and accumulator
0D: NOT [r] - NOT a register
0E: SRR [r] - Shift register right
0F: SRL [r] - Shift register Left
10: JUP [d8] - Jump to a location
11: JPP [r] - Jump to a register value
12: JPL A, [d8] - Jump if accumulator is less than 0
13: JZO A, [d8] - Jump if accumulator is 0
14: JPG A, [d8] - Jump if accumulator is greater than 0
15: JLE A, [d8] - Jump if accumulator is less than or equal to 0
16: JGE A, [d8] Jump if accumulator is greater than or equal to 0
17: JNZ A, [d8] Jump if accumulator is not 0
18: CLR [r] - Clear a register
19: INP [id] - Store INPUT id in accumulator
1A: MOV pA, [r] - Move the value at address A register r
1B:  MOV [r], pA - Move register r into address A
1C: MOV [p], A - Move a value in a pointer to the accumulator
1D: MOV A, [p] - Move the accumulator to a location
1E: MLT [r], A - Multiply register r by the accumulator
1F: DIV [r], A - Divide register r by accumulator


REGISTERS:
00: 
REGISTER 1
01: REGISTER 2
02: REGISTER 3
04: REGISTER 4
05: ZERO FLAG (R)
06: 
PC (R)
07: ALU Result (R)


Update Notes:
Welcome to the 3rd iteration of my Femboy-8 CPU! This might be the last version with 32 instructions.


To-Do:
Increase amount of registers to 8
Make a simple command line
Make an assember
Make a simple operating system for the CPU
Add rgb output


project.name
0 Stars     14 Views
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Functional Electronic Machine Binary Operator Yes - 8-bit cpu

Working on a new CPU: Femboy-16


ASSEMBLER:

https://output.jsbin.com/wutikij


INSTRUCTION SET:
00: NOP - Nothing
01: HLT - Halt program
02: OUT [id] - Output the accumulator out of an output
03: LDI A, [d8] - Loads immediate 8 bit word into the accumulator
04: MOV [r], A - Move register to accumulator
05: MOV A, [r] - Move accumulator to register
06: INC [r] - Increment a register
07: DEC [r] - Decrememt a register
08: ADD [r], A - Add the accumulator from a register
09: SUB [r], A - Subtract the accumulator from a register
0A: AND [r], A - And the register and accumulator
0B: IOR [r], A - OR the register and accumulator
0C: XOR [r], A - XOR the register and accumulator
0D: NOT [r] - NOT a register
0E: SAR [d8] - Barrel shift accumulator right
0F: SAL [d8] - Barrel shift accumulator left
10: JUP [d8] - Jump to a location
11: JPP [r] - Jump to a register value
12: JPL A, [d8] - Jump if accumulator is less than 0
13: JZO A, [d8] - Jump if accumulator is 0
14: JPG A, [d8] - Jump if accumulator is greater than 0
15: JLE A, [d8] - Jump if accumulator is less than or equal to 0
16: JGE A, [d8] Jump if accumulator is greater than or equal to 0
17: JNZ A, [d8] Jump if accumulator is not 0
18: CLR [r] - Clear a register
19: INP [id] - Store INPUT id in accumulator
1A: MOV pA, [r] - Move the value at address A register r
1B:  MOV [r], pA - Move register r into address A
1C: MOV [p], A - Move a value in a pointer to the accumulator
1D: MOV A, [p] - Move the accumulator to a location
1E: MLT [r], A - Multiply register r by the accumulator
1F: DIV [r], A - Divide register r by accumulator


REGISTERS:
00: REGISTER 1
01: REGISTER 2
02: REGISTER 3
04: REGISTER 4
05: ZERO FLAG (R)
06: PC (R)
07: ALU Result (R)


Update Notes:
So this is the 4th iteration of my CPU lol... I added a few programs for you all to try out and you can even use an assembler now!


To-Do:
Increase amount of registers to 8
Make a simple command line
Make an assember
Make a simple operating system for the CPU
Add rgb output


project.name
0 Stars     7 Views
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Equality Comparison (8-bit)

Equality Comparison (8-bit)

project.name
0 Stars     3 Views
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Memory Practice

Memory Practice

Adjustable 8-bit adder which either loads values from two different registers into an 8-bit adder or sequentially adds the current output value of the adder to the value stored in the first register. Practice for RAM unit application, register creation and organization, bit splitting and compression, and sequential logic.


project.name
0 Stars     2 Views

8-bit Addition

8-bit Addition

My first dive into logic gates! I learned how to add two 8-bit numbers together with an overflow value added. 


project.name
1 Stars     1 Views
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halfbyte-enable counter

halfbyte-enable counter

More practice for sequential logic, implementing multiple sub-circuits to simplify the functionality of the design.