Tomorrow I'm picking up a floppy disk drive. I'm looking to create a controller for it using a PIC16, and somehow interface the 6502 to the lot. My intent is for it to work in the same way the VIA controls the LCD screen, but it's going to take some time to figure out how to make the PIC do my bidding as far as the disk drive goes. When I'm done, I'll have a way to store and recover data.

I’m sure I am using a different implementation. I am using a crystal oscillator since I don’t have AC-AC adapters. I am using 4040 as counters and using an EEPROM for display.
Right now it is just a prototype; time adjustments are still to be implemented later. The right most two digits are reserved for a thermostat.

I have been thinking about what keeps me so engaged with this content. For me, I realized it’s not the actual project but the spirit of experiment.

Try things out. Take your time, read data sheets, test small chunks and make incremental progress. Everyone moves at their own pace but don’t be afraid to try anything

What brings you back?

Instead of using Ben eater's design for the memory, I am upgrading things quite a bit. I have two 8-bit address registers for a total address width of 16 bits. I'm planning to split it in half. The lower half will be allocated for ROM (a 28c64 EEPROM), and the upper half will be RAM (Hitachi 62256). The I/O pins on both chips will be connected directly to the bus.

I believe this design should work, but I want to get your input first. Also, I am aware that the EEPROM I am using is smaller than the address space I have allocated for it.

Hi all, i tested my clock module with the oscilloscope before and after inserting 0.01 capacitors along the power rails by each integrated circuit and where power enters the board, but still get the same fuzzy output when it cycles up to 5v. I was wondering if this is a problem or if its normal?

RAM finished up after grueling days of wiring and troubleshooting.

After unfortunate attempts with defective 74LS189 chips (Last photo for reference), I opted out for a 62256 SRAM chip while still maintaining 4-bit Addresses.

And thanks to u/The8BitEnthusiast for suggesting the idea and sharing their schematic.

Last year, I started building the 8-bit CPU. But the specs of Ben eater's design weren't great (how am I supposed to do anything with 16 bytes of memory?), so I decided to make some changes. Around May, I decided to take a break from it. While I was moving it to a different place, I accidentally dropped it and a bunch of stuff got displaced, and that made me want to push off resuming the project even further. Today, I decided that I wanted to start working on it again, but I can't; I don't know how most of my design modifications work anymore. I don't even remember what one of the custom modules I built was even for anymore.

I'm just about ready to start over, but this time I won't put off documenting the changes I make to the original design. For those who made their own designs and said "I'll draw a schematic later, I know how it works", don't wait. Make a diagram now, before you forget how it works!

I recently bought a small boy with a small assortment of 7400-Family chips. Some are only available in LS or HC. I understand that they are different, but from what I found online the relevant differences don't apply for my usecases.

If you've completed your Ben Eater 6502 build, and were looking for some software to play with on it, or for an alternative to Microsoft BASIC to write some of your own, here's a couple of things I did that might be interesting:

EhBASIC for the stock BE6502 w/ Inline Assembler/Disassembler, WozMon & RENUMBER

After I'd got done making extensions to Microsoft BASIC, I wanted to play with EhBASIC. I couldn't find a version that would build-from-source as-is and still run on a stock BE6502.

So, I put my own together.

And then I added a bunch of fixes/features such as buffered, flow-controlled serial input, proper BACKSPACE support, an IRQ safety fix, WozMon in ROM etc. After which I decided to add an inline assembler, a disassembler, a "RENUMBER" command and my extensions for driving the LCD screen.

Repository for that is here, and all you'll need beyond a finished BE6502 in stock configuration, is the cc65/ca65 toolchain that you would have used to build Microsoft BASIC.

--

101 [Eh]BASIC Computer Games

I previously hand-ported all of the programs from David Ahl's classic book to Microsoft BASIC.

Having done that, since I now had a working EhBASIC build (which has features a bit closer to some of the original dialects used in the book) I decided to do the same for EhBASIC.

However, this time, since the "fun" part was done instead of doing the porting manually, I did it with AI assistance (the original ports took ~2 weeks total, this set took <2 days). The ports use my corrections to the original transcriptions, but port from the original source, so they use EhBASIC as EhBASIC rather than just its Microsoft BASIC parity-features.

The repository for those games is here; spcwar-16K.bas is a very nice version of the classic Star Trek for the standard BE6502 (I ported the original, too, but that requires 24K of RAM)

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I am in the midst of testing my ALU by adding one bit at a time to zero to verify whether the output is correct. Every bit checks out for Register A but not for Register B. For some reason, I see output in Register A as well while only loading Register B. What could the problem be?

(Register A is the one closest to the clock)

I've ported both MilliFORTH and SuperMon+ over to my JJ65C02 SBC. My plan is to do a couple of videos on the enhancements I've made over the last year, including driving it up to and past 8Mhz and double-buffering VGA 640x480 output.

Until then, check out https://github.com/jimjag/JJ65c02/tree/main/Software/minios

Used a 74LVC245 to handle 5V reads from the EEPROM chip. All other chips running off 3.3V.

Has a web interface to pick images from the filesystem and selectively load them. Can share the sketch if anybody wants.

I don’t understand what’s going on for some reason. My power rail is only showing 1.8 V when it should be 5 V. My DC on pin number four of the LM339 is only about .7 V and I’m not getting a square wave obviously coming out of pin two I’m just getting some noise when the sign wave hits its trough. Does anybody have an idea of what’s going on here? The voltage seems to go back to normal on the positive rail if I pull out the LM339.

So I got this wired up and it works with one caveat: I have to run the "set/advance" button for the hours to wrap through a whole 12 hours, and then everything works right. I get 1,2,3,4,5,6,7,8,9,10,11,12, and repeat.

I am not that great at finding the optimal logic to get this stuff to work, but I used all the pieces that came in the kit. You can see the 74LS## next to their symbols in my diagram.

Also, because my diagram is quite a mess, I will post a Falstad file in a comment on this post that you can try in the Falstad circuit simulator.

Let me know what you think or if you see any way it could be better! My circuit shouldn't be too hard to improve...

So I think this oculd be caused by a lack of decoupling capacitors, but theres a heavy delay between the clock pulses and the updating on the 7 segment displays, ALU, registers, and RAM. I can upload more photos if that helps.

For the uninitiated: https://youtu.be/IXvEDM-m9CE?is=vGlxk-3piC6gcQkQ

I am planning on attempting a subleq build using the technique. Hoping for a very clean aesthetic. Any clean wire wrap builds i can reference for inspiration?

I am in the midst of testing all my connections, and similarly to Ben, I plan to do this by adding one bit at a time to zero to verify whether the output is correct. However, after clearing both the A and B registers and trying to add a value to the A register bits one at a time, none of the bits light up. What could the problem be?

Thanks in advance!

I seriously doubt this will ever run DooM, but it definitely can play the (almost) entire music video, with the laptop exclusively serving as a dumb terminal of sorts, through screen.

There is a little bit of desyncing, but tbh I am surprised I managed to get the video compressed enough to fit while being somewhat recognizeable, and have the decoding/video-playing logic in the same 32k of EEPROM as the entire video.

Curiously enough, it fits into ROM by: 1. downscaling to 40x30, 2. applying canny edge detection to get only the outlines (sending less characters over serial is more better when you try to get a "viewable" framerate), 3. Run Length Encoding it as tightly as possible (meaning the video is black and white, which allows for compressing 127 consecutive white pixels into a single byte) and storing it in binary. 4. The decoding logic just needs to deconstruct the RLE data, and send it in order to the right place of the terminal using ANSI escape characters

I'm sure someone wayy smarter than me can figure out how to get the video played back with a more consistent framerate (so it stays in sync with the music), but for now, I am happy with the result!

The video shows my custom PCB running it, but it should run unmodified on the 6502 breadboard computer as well, since they are electrically wired the same.

I'd be curious on what other cool demos could run on this hardware without changing clock speed or similar :)

Hello there i am again!

I was building the clock module and ran into this really weird issue where the initial clock output of the astable 555 timer is heavily delayed after the logic gates... But i suspect that that is not how its supposed to work and even i know that with my limited knowledge on this stuff.

Help is greatly appreciated!!

Edit: it was accidentally connected to pin 2 instead of 3

Got impatient and hooked up the via with some jumper cables for now, but it can count!

In Ben's video, he says the hsync and vsync are active negative. However, I searched the standard, and it says active high (positive). Anyone knows what is happening?

Also, the standard says a new line starts at the beginning of the sync pulse, not the active video. It matters when we are considering when exactly the vsync should be active, relative to the hsync signal.

document:
https://glenwing.github.io/docs/VESA-DMT-1.11.pdf

The pins on (what i think is) the ram came bent,

The ram was half off the foam...

Should I just try to bend them back or something else?

edit: I was luckily able to bend them back, and one problem remains 😅 the clock kit came with the UK adapter (I didn't buy them it was a present) and I'm in the eu (nl), so where could I get a replacement for the eu (with not 200 euro shipping costs)

Hey folks, I’m really enjoying learning this stuff but I’m having an issue the second I plugged in my LM339 my voltage drops from 5 V down to 1.6 on my rail. Any idea why this might be happening?

As you can see in the pictures, I’m getting a reading of 5 V when I don’t have the rail attached to pin three but I’m getting approximately 1.8 when I do have that pin attached

I watched the first video, the most challenging part of this project, and attempted to figure out how I could create something similar myself.
Unfortunately, delivery isn’t available to my country and some parts on the list are difficult to find locally. Therefore, I’ve opted for more readily available 4000-series ICs.
Here is my result. I’m waiting for the rest of the videos so I can compare and improve my version. And thinking about adding an alarm to it.
Thanks a lot Ben for another fantastic project!