Видео 203
Просмотров 1 526 564

30:56

Storage (SD Card Support) - IO from Scratch - Part 8

26:10

Palette PCB - VGA from Scratch - Part 19

30:01

Hardware SPI Continued - IO from Scratch - Part 7

31:13

Hardware SPI - IO from Scratch - Part 6

26:14

Output PCB - VGA from Scratch - Part 18

1:22:14

Bad Apple on the Homebrew CPU!

Viewers have been asking for this. Bad apple is a tune and video with a rich history that has been “ported” to many low powered systems as a technical challenge.
This is one of the most complex demos I’ve implemented on the system with synchronized Audio, Video, SD card and the UART.
You’ll want to watch the follow up video “Porting Bad Apple to the Homebrew CPU!” where I discuss many of the technical challenges and my solutions. ruclips.net/video/2g1h5coj6iA/видео.html

Видео

30:56

Porting Bad Apple to the Homebrew CPU!

Просмотров 10 тыс.Месяц назад

The Bad Apple Demo is one of the most complex demos I’ve implemented on the system with synchronised Audio, Video, SD card and the UART. In this video I discuss many of the technical challenges and my process for solving them. 0:00 Intro 0:22 Overview 0:59 About Bad Apple 2:29 Graphics Rendering 8:28 Time & Streaming 12:06 Lyrics 14:06 Graphics Compression 21:33 Sound 26:38 Outro 27:04 Bad Appl...

Storage (SD Card Support) - IO from Scratch - Part 8

26:10

Storage (SD Card Support) - IO from Scratch - Part 8

Просмотров 7 тыс.2 месяца назад

I’ve been wanting to add some kind of persistent storage to the build. In this video I discuss various options for persistent storage before building the interface to interface a 3.3v SD card to the system. Most of the work to interface to the SD card is in the coding, I have an abridged version of the coding in this video, and a longer edit with more detail on the extras channel video here: ru...

Palette PCB - VGA from Scratch - Part 19

30:01

Palette PCB - VGA from Scratch - Part 19

Просмотров 7 тыс.3 месяца назад

In this video we convert the palette circuit from breadboard to pcb. This contains work from parts 11 and 12 in the vga series. Converting exiting circuits to pcb sometimes feels like it doesn’t progress the build, but it is an essential part of the process. This is a huge step forward in the vga circuit allowing me to run all the core functionality so far without any breadboards hanging off th...

Hardware SPI Continued - IO from Scratch - Part 7

31:13

Hardware SPI Continued - IO from Scratch - Part 7

Просмотров 4,9 тыс.4 месяца назад

This is the second half of the Hardware SPI video that would have been far too long. As such the beginning jumps strait into implementation, I usually try and start in a less sudden way. In this video I add hardware support for the remaining two lines MOSI and the Clock and unlock sustained transfer speeds at the full clock rate of the cpu, 8 megabits per seconds! I made a couple of tweaks to t...

26:14

Hardware SPI - IO from Scratch - Part 6

Просмотров 7 тыс.4 месяца назад

Bit banging SPI produced some functional results but I’d like to improve my overall data transfer rate, and that means adding some hardware support. I identify 4 areas we can add some assistance to and add some circuitry for the first two. This will be followed (I hope very soon) with the second part finishing of the conversion. I had originally planned to this all in one video but it very quic...

1:22:14

Output PCB - VGA from Scratch - Part 18

Просмотров 9 тыс.5 месяцев назад

In this video I turn the final output circuitry into a PCB. This is circuits from multiple vga videos going all the way back to the first in the vga series. You can probably guess from the length of the video, I ran into some problems with this one. I thought about splitting this into two videos but I couldn’t find a place where it felt right. Conceptually though it has two halves. Firstly the ...

GPIO over SPI over GPIO - IO from Scratch - Part 5

25:48

GPIO over SPI over GPIO - IO from Scratch - Part 5

Просмотров 6 тыс.5 месяцев назад

I wanted to interface a different SPI device, this let’s us test connecting multiple devices at once but I also wanted to try out a different spi mode. In the future I want to interface to a complex mode 0 device so I went looking for a basic mode 0 device to experiment on. I found the MCP23S08 which is an 8 line IO expander. Since the GPIO lines are not being used for SPI this gives us some ge...

Final Peripherals Backplane - Making an 8 Bit pipelined CPU - Part 104

45:26

Final Peripherals Backplane - Making an 8 Bit pipelined CPU - Part 104

Просмотров 8 тыс.6 месяцев назад

When I started this project I had a vision of a single backplane with all the peripherals, vga and cpu modules plugged in. I’ve since refined that a little to separate the core cpu and then two add-on boards, one for peripherals and one for the vga. Today I share what feels like a massive step forward towards finishing the project, what I believe to be the final Peripherals backplane. In the fi...

Signal Cleanup - VGA from Scratch - Part 17

13:34

Signal Cleanup - VGA from Scratch - Part 17

Просмотров 8 тыс.6 месяцев назад

This is a small modification to the vga circuitry but something I wanted to talk about before designing the final output circuit pcb. This is an update on a tweak I originally did to clean up the output of the Doomed demo, that tweak is less effective now due to the evolution of the vga circuit but in this video I discuss what it was, why it doesn’t work as well now and implement a similar circ...

SPI (Bit Banging)- IO from Scratch - Part 4

30:04

SPI (Bit Banging)- IO from Scratch - Part 4

Просмотров 9 тыс.7 месяцев назад

In this video I use the GPIO lines to “bit bang” the Serial Peripheral Interface (SPI) protocol. I’m open to a discussion on keeping SPI as pure code, creating a full implementation of the protocol in hardware or trying a hybrid approach aiming to get maximal improvement from minimal components. My test device is a DS1391U, these only come as SMD parts but I soldered one onto a dip adapter abou...

Interim Backplane - VGA from Scratch - Part 16

30:37

Interim Backplane - VGA from Scratch - Part 16

Просмотров 6 тыс.8 месяцев назад

The last VGA video contained an “unplanned demonstration” of how fragile these builds can get with lots of temporary wiring. In preparation for some more complex work I decided to spend some time tidying the wiring up and integrating the existing modules on a new temporary backplane. If you are just following the circuit logic you can safely skip this video but if you want to see the detail of ...

SNES Controller Interface - Part 3 - Final PCB Module

45:00

SNES Controller Interface - Part 3 - Final PCB Module

Просмотров 6 тыс.8 месяцев назад

The circuit is final so the last step is to convert the circuit to a PCB. After the audio controller PCB the remaining space is better defined so I was able to define the area I had to work with. I decided it would be fun to put the 12 button led’s in the shape of the controller rather than just in a row. The first revision of the board has an error, I assigned the wrong led’s to the buttons, I...

Timing Tweak - VGA from Scratch - Part 15

17:36

Timing Tweak - VGA from Scratch - Part 15

Просмотров 7 тыс.9 месяцев назад

This video is about a timing issue in the vga circuit that I’ve been avoiding talking about with the assumption that a good time to discuss it would present itself. That didn’t happen so it’s getting it’s own video now before it becomes either a blocker or something I have to hand wave and I don’t like making circuit changes that I haven’t talked about. I do have to talk about the sprite circui...

Interface PCB - Audio from Scratch - Part 10

28:35

Interface PCB - Audio from Scratch - Part 10

Просмотров 7 тыс.9 месяцев назад

Converting the new Audio controller to a final PCB circuit was long overdue, it was a bit of a struggle working out the shape the pcb was going to be. Always an issue with trying to design and build systems incrementally in the way I have been. I’m very keen on bringing all the core components of the build to a nice conclusion before I start any significant new work. 0:00 Intro 0:30 Discussion ...