This really needs a circuit diagram with address lines and control signals being labelled, rather than just pointing at chips and wires on the prototyping boards. You clearly understand what you've designed very well, but without a clearer picture of the connectivity, it's hard for the viewer to follow what you're describing, especially if they're not familiar with some of the chips. Thanks.
This really makes me feel like I need to get back to my own huge messy computer+video display breadboard project. Using a flash chip to compact the video timing signal generation is a really interesting approach as an alternative to "smart" programmable logic. (And a cool throwback to how fast PROMs were often used for this sort of job before PALs/GALs became common.) I'm interested to see how this is going to progress. The approach I'm taking with my own project is using an ATMEL 8-bit MCU as a CRTC, because I want to be able to support multiple video modes with different addressing strategies (while keeping the actual pixel generation and shared VRAM access "real hardware", vs. the now common approach of using a hulking powerful MCU as a complete graphics coprocessor/video generator), but it is serious overkill for a lot of applications.
Thanks, my friend. I love your videos, too. My first computer was a TRS-80 Model I level II. I've been wanting to build a work-alike on breadboards, but I misplaced my copy of the "TRS-80 Technical Reference Manual" when I moved to Florida.
Hi Ben! I can´t believe you are using a LCD display!!!! It adds delays you have to wait during writes. You know it... I´d suggest you use a parallel FIFO and have an Arduino read the FIFO and write the LCD, or use a dual-port RAM. The FIFO is a sequential memory, you could have special codes in 0x80 .. 0xFF range to command a clear screen, home, goto line 0/1 etc. and use like a the FIFO like a serial port device. The Dual-Port RAM is a... Random Access Memory! you can write anywhere you want, anytime, so you can have 20 bytes for line 0 and 20 bytes for line 1, and write on these addresses. The Arduino would continuously read, compare to local copy and update the LCD when needed. I did something quite similar in the past, using only software and a 500ns interrupt. The interrupt would drive a state machine that continuously writes to the LCD. So the main program did not have to wait the LCD, it would write a memory buffer (zero delay) and then sometime later the buffer would be updated on physical LCD (with a little lag)
Thanks for the suggestion. I"m not Ben, though; I'm Scott. My project is based on Ben Eater's 6502 project. If you haven't seen his videos, you are missing out! www.youtube.com/@BenEater
@@p.scottdevos1235 Ohhh.... SHAME ON ME!!!! Anyway.. I think you are most likely to use a FIFO or Dual Port than me. I just don´t have time to play with these, unfortunately.
Interesting, but I immediately red-flagged the lack of decoupling capacitors - nothing digital is guaranteed to work without them, you run on luck alone... 100nF ceramic for each chip is a good starting point.
Informative one! Wondering if any custom PCBs may help for any upcoming content or project build? Would love to sponsor and reach any collab together! (PCBWay zoey)
@@p.scottdevos1235 Sure thing! Pls keep me updated anytime you need! You can find my contact info under this account, looking forward to hearing from you soon! 🤗
This really needs a circuit diagram with address lines and control signals being labelled, rather than just pointing at chips and wires on the prototyping boards. You clearly understand what you've designed very well, but without a clearer picture of the connectivity, it's hard for the viewer to follow what you're describing, especially if they're not familiar with some of the chips. Thanks.
Thanks for the suggestion. When I have the design settled, I plan to draw one up.
Your channel is underrated. Keep up the good work
Thank you! That is so kind.
I have to get back to my board. I have yet to get the second chip to blink the lights lol appreciate your videos to add on
Thank you. I enjoy making them.
This really makes me feel like I need to get back to my own huge messy computer+video display breadboard project.
Using a flash chip to compact the video timing signal generation is a really interesting approach as an alternative to "smart" programmable logic. (And a cool throwback to how fast PROMs were often used for this sort of job before PALs/GALs became common.) I'm interested to see how this is going to progress. The approach I'm taking with my own project is using an ATMEL 8-bit MCU as a CRTC, because I want to be able to support multiple video modes with different addressing strategies (while keeping the actual pixel generation and shared VRAM access "real hardware", vs. the now common approach of using a hulking powerful MCU as a complete graphics coprocessor/video generator), but it is serious overkill for a lot of applications.
Thanks, my friend. I love your videos, too. My first computer was a TRS-80 Model I level II. I've been wanting to build a work-alike on breadboards, but I misplaced my copy of the "TRS-80 Technical Reference Manual" when I moved to Florida.
I might be imaginnig it, but the further your videos go on the more your voice reminds me of Ben Eater's.
Thanks! I love Ben Eater's voice.
Hi Ben! I can´t believe you are using a LCD display!!!! It adds delays you have to wait during writes. You know it... I´d suggest you use a parallel FIFO and have an Arduino read the FIFO and write the LCD, or use a dual-port RAM.
The FIFO is a sequential memory, you could have special codes in 0x80 .. 0xFF range to command a clear screen, home, goto line 0/1 etc. and use like a the FIFO like a serial port device.
The Dual-Port RAM is a... Random Access Memory! you can write anywhere you want, anytime, so you can have 20 bytes for line 0 and 20 bytes for line 1, and write on these addresses. The Arduino would continuously read, compare to local copy and update the LCD when needed.
I did something quite similar in the past, using only software and a 500ns interrupt. The interrupt would drive a state machine that continuously writes to the LCD. So the main program did not have to wait the LCD, it would write a memory buffer (zero delay) and then sometime later the buffer would be updated on physical LCD (with a little lag)
Thanks for the suggestion. I"m not Ben, though; I'm Scott. My project is based on Ben Eater's 6502 project. If you haven't seen his videos, you are missing out! www.youtube.com/@BenEater
It’s not Ben
@@p.scottdevos1235 Ohhh.... SHAME ON ME!!!! Anyway.. I think you are most likely to use a FIFO or Dual Port than me. I just don´t have time to play with these, unfortunately.
Interesting, but I immediately red-flagged the lack of decoupling capacitors - nothing digital is guaranteed to work without them, you run on luck alone... 100nF ceramic for each chip is a good starting point.
There is a 100nF cap on each power rail.
@@p.scottdevos1235 But not per chip right on the pins?
@@MarkTillotson Correct
Informative one! Wondering if any custom PCBs may help for any upcoming content or project build? Would love to sponsor and reach any collab together! (PCBWay zoey)
Perhaps once I get the project working completed. Thanks for reaching out!
@@p.scottdevos1235 Sure thing! Pls keep me updated anytime you need! You can find my contact info under this account, looking forward to hearing from you soon! 🤗
PCB is good for SMT
And move the mouse cursor off-screen before recording
Yes. I should be more careful about that.
oh I Now Subber 404,,HAHAHAHAAAAAA
Thanks for the sub!
Too much ‘er’ and ‘um’ and correcting yourself. Maybe a script will help.
Thanks for the suggestion.