8bit-cpu
Schematics & code for my 74LS-based 8-bit MK1 CPU (by vascofazza)
eater-sap-1-improvements
Improvements and modifications made to the Ben Eater SAP-1 breadboard computer (by michaelkamprath)
8bit-cpu | eater-sap-1-improvements | |
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2 | 14 | |
297 | 48 | |
- | - | |
0.0 | 2.7 | |
over 1 year ago | 8 months ago | |
Python | Assembly | |
MIT License | Creative Commons Zero v1.0 Universal |
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
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Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
8bit-cpu
Posts with mentions or reviews of 8bit-cpu.
We have used some of these posts to build our list of alternatives
and similar projects. The last one was on 2021-01-19.
- Is it possible for just one person to build a full working computer from scratch?
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Show HN: Virtual breadboard in your desktop browser, inspired by Ben Eater 6502
Code and schematics: https://github.com/vascofazza/8bit-cpu
eater-sap-1-improvements
Posts with mentions or reviews of eater-sap-1-improvements.
We have used some of these posts to build our list of alternatives
and similar projects. The last one was on 2022-06-04.
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Next project for my PUTEY-1 TTL CPU: A speech synthesizer!
When I figure out why the "voice" is unintelligible, I will be certainly posting all the details and making a video as I have done with my prior projects for this computer. Subscribe to my YouTube or follow my GitHub repository to get alerts.
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It took about a week, but my PUTEY-1 TTL CPU has calculated all the prime numbers to about 1.1 million.
The details of my design evolution from the Eater SAP-1 to what you see here are documented at my GitHub repository. You can also watch video overviews if each improvement project at my YouTube channel, the I haven’t yet made the video for the ALU that’s enabling multiplication and division through bit shifting. That’s only at my GitHub at the moment.
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My TTL CPU is now operating at 300 KHz clock and can calculate 32 bit prime numbers.
Ha ... yeah, it was overkill, but the 32K was just sitting there unused. If you check out my code for the prime number calculation, you'll see the stack is well used. However, I haven't cracked the 256 byte depth yet.
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has anyone programmed an EPLD?
I am using the ATF22V10C in my build. Works great. I’ve made some notes on programming them here: https://github.com/michaelkamprath/eater-sap-1-improvements/tree/advanced-alu/advanced-alu/pld-files
- I’ve built out my ALU upgrade for my TTL CPU. I use 74LS382 function generators, 74LS194 bit shifters, and 74LS682 comparators to significantly upgrade what can be computed from the original 74LS283 4-bit adders.
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8-bit CPU project upgrading
I’ve done a number of upgrades myself. They are documented here: https://github.com/michaelkamprath/eater-sap-1-improvements
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Stuck with strange voltage behavior in RAM module that goes away when using a multimeter
Here's the write button. https://i.imgur.com/N3WgqR9.jpg I've inverted it from a pull-up switch to GND, to a pull-down switch to VCC, using Michael Kamprath's improvement recommendations found at https://github.com/michaelkamprath/eater-sap-1-improvements/tree/main/improving-reliability-of-ram-module
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The next iteration of my extend breadboard TTL CPU is working. Time to finish project documentation and create an overview video.
This iteration on the CPU focused on implementing a 8-bit instruction register. However, doing this required me to rethink many parts of the computer, notably the memory map and the control logic. Details on what I accomplished in this project can be found in my GitHub repository: https://github.com/michaelkamprath/eater-sap-1-improvements/tree/main/instruction-register-8-bit
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My updated 16 bit memory + updated control logic + memory map controller + 8 bit instruction register is ready to be integrated into my breadboard CPU.
If you want to read up on what I am doing here before I create a video on it, I have documented everything here (though there are a few bits I still need to document).
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The start of my effort to add 16-bit memory addressing to my SAP-1. Built so far at 16-bit program counter, memory address register, and run mode selector. The design now has a proper address bus (purple wires) in addition to the 8-bit data bus.
You can check out the current state of my design on my ram-upgrade branch in my GitHub repository. It's still a work in progress, so don't yet expect the same level of documentation or completeness my other modules have.
What are some alternatives?
When comparing 8bit-cpu and eater-sap-1-improvements you can also consider the following projects:
scikit-rf - RF and Microwave Engineering Scikit
8-bit-computer - Documentation of my 8-bit computer build
skidl - SKiDL is a module that extends Python with the ability to design electronic circuits.
kicad_footprints - A collection of all the KiCad footprints on the internet
kicad-libraries - Set of symbols/footprints/models that I've created for my projects.
pyxel - A retro game engine for Python
bespokeasm - An assembler that can be configured to work with most any instruction set.
ImGuiColorTextEdit - Colorizing text editor for ImGui
EaterEmulator - Ben Eater's 8-bit breadboard computer emulator in python
pppp - Playfield Pixel Perfect Pro: The ultimate Atari 2600 playfield designer
8bit-cpu vs scikit-rf
eater-sap-1-improvements vs 8-bit-computer
8bit-cpu vs skidl
eater-sap-1-improvements vs kicad_footprints
8bit-cpu vs kicad-libraries
eater-sap-1-improvements vs skidl
8bit-cpu vs pyxel
eater-sap-1-improvements vs bespokeasm
8bit-cpu vs ImGuiColorTextEdit
eater-sap-1-improvements vs EaterEmulator
8bit-cpu vs pppp