HDMI video from your Apple II with this cheap and simple project (A2DVI)

Comments · 279

• AD

  @adriansdigitalbasement · 2 years ago · pinned

  Just a small clarification: The '245 buffers are required on this project due to the way the Address and Data lines are multiplexed going into the RP2040. There aren't enough GPIO lines without doing that when combined with the GPIO needs of the HDMI connector.

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• MA

  @MacRetroFly-ef8cc · 2 years ago (edited)

  I&apos;m the developer of the A2DVI firmware - and worked with Ralle on this project. There several reasons why the IIgs is currently not supported. One is that it supports arbitrary colors (configurable palette). The DVI/HDMI uses a protocol. The PICO isn&apos;t fast enough to really compute this on the fly. A2DVI needs to use a trick, basically relying on precomputed protocol fragments - prepared for each pixel combination that it ever needs to display. Works great with Apple II due to fixed and limited colors. IIgs would increase the difficulty by a lot (pre-computed table size would explode). Also, the IIgs supports &quot;scan line interrupts&quot;. IIgs software can change the palette in between scan lines. So, it&apos;s not enough to just render the screen: but each scan line would need to be rendered at the exact correct moment of time, using the current palette settings. That adds a whole new layer of complexity. Maybe the PICO2 is able to do it. Maybe we&apos;ll have to wait for another successor - like PICO3...<br>The remaining issues with Video7 mentioned by Adrian in the video are already fixed with the latest firmware. Also, the suggestion to use the switch for video mode configuration is already supported now.<br>Final comment: (--comment redacted by me: I was originally being &quot;very critical&quot; here of some &quot;clone&quot; designs of the original A2DVI PCB, which we published on github with Gerbers+KiCad. My criticism included Chris and his variant shown here in this video. My criticism wasn&apos;t quite fair and hit the wrong person. I apologise - and therefore removed this part of the comment...).

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• MM

  @MM. · 2 years ago (edited)

  <a href="https://www.youtube.com/watch?v=rrM6bPCk8DM&amp;t=1812">30:12</a> I&apos;m now convinced that 3D bar charts were expressly invented to demo the graphical abilities of 80s computers. I&apos;ve never seen them used in any serious context.

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• BR

  @BryonLape · 1 year ago

  Me: 40+ years of never touching the edge connector with my fingers.<br>Dude in video: fingers all over the edge connector.

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• PS

  @pseudotasuki · 2 years ago

  The chip in the Pico 2 (RP2350) can do DVI output without overclocking or PIO. It has a new capability called high-speed transmit (HSTX) which is specifically dusigned for applications like this.

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• BO

  @bouffman88 · 1 year ago

  Also still love seeing the Plexus in the background.

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• GA

  @GarthBeagle · 2 years ago

  Yes! There&apos;s so many new projects like this that have been developed in recent years to support our retro computers ❤

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• EX

  @ExpressoMechanicTV · 2 years ago (edited)

  Always wanted an Apple II when I was a kid, but had to make do with a ZX81, as Apple II was way too expensive. Still a great machine for its age.

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• JM

  @jmpattillo · 2 months ago

  It’s just delightful that the configuration software is using an Apple 2 to “program” a pi pico.

• AR

  @aresaurelian · 1 year ago

  And now we unlocked the future of computer system which has every electronic module as a tiny computer running software, instead of motherboards and cards having hardware logic. It makes the system fully dynamic and modular. The entire system can change behavior completely, as a chameleon system.

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• IA

  @IanScottJohnston · 2 years ago

  Adrian......you are knocking this out the park. Really well explained leading up to the HDMI card.

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• LE

  @levimaaia · 2 years ago

  The analog effects mode is amazing! Thanks for the side-by-side comparison. I love how it simulates the analog video world with a modern tool in a way that preserves the essence and feel of the vintage experience. This is a spot-on implementation.

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