Debugging the SFC to CD mechacon interface. Timing to work out on the PLD side to get reliable reads/writes each way. The scope shows the individual nibbles of an ACCESS command being transferred to an ATMega microcontroller that's standing in for the real mechacon chip.

Some progress on the Nintendo PlayStation: some programmable logic acts as a bridge between SFC and CD hardware. Set up in a loopback configuration, the BIOS now thinks it's talking to the mechacon MCU. Mock firmware is ready to go once this part is debugged.

Can't imagine anyone following me isn't following Bob already, but here's us chatting about hardware preservation, the Neptune and other such topics.

My @cosam-the-great.bsky.social Neptune board up and running! Shoutouts to the @retrorgb.bsky.social and @dubesinhower.bsky.social Discords for some troubleshooting at the end. By far the hardest project I've taken on. It's a shame tariffs have put a Neptune shell out of the budget :(

To help with fixing the region flicker, i made a flex pcb. github.com/Board-Folk/N...

Minor update to the Neptune PCB, mostly to better support more donor revisions. Focus of the next release will be attempting to simplify and improve composite video. github.com/Board-Folk/N...

Neptune revision 1.4 has just been released, including the "region flicker" fix and some BOM updates/corrections. This one was a real team effort, so thanks to all who contributed! github.com/Board-Folk/N...

Thanks to the tireless efforts of the community, the Neptune "region flicker" issue has been diagnosed and fixed! To commemorate in true #Sega style, here's a service bulletin, complete with traditional inconsistent fonts and dodgy layout.

Neptune builders/users should be aware of this very weird issue. TLDR: a few games that actively access the region/version settings of the console display artifacts in certain mode combinations. If anyone has more ideas regarding the cause we're all ears! github.com/Board-Folk/N...

If you planned on building a #Neptune #SegaNeptune via @cosam-the-great.bsky.social’s board, you should seriously consider this pre-populated version, as it’ll make a really hard project a bit easier. Plus, Jan used great quality caps. Links and more info: www.retrorgb.com/neptune-pcb-...

PC Engine GT/TurboExpress main PCB repro is now public. If you have the skills and knowledge, there is still a lot to be identified on the schematic! Thanks again to @pointerfunction.bsky.social for the donor hardware, testing and troubleshooting. github.com/Board-Folk/P...

Woohoo! Nice work Dennis, now it's verified I'll be publishing the project any time now, including preliminary schematics.

Reasonably convincing except for the lack of volume knob and ISA bracket. No actual audio coming out of it yet, I suspect my AliExpress special AY chips may not be 100% genuine...

It’s alive!! Thanks @cosam-the-great.bsky.social for the awesome project. Definitely the hardest project I’ve ever attempted.

Pretty niche this one, even for me. My non-running A530 started losing pads during troubleshooting, which was going slowly without schematics. Hopefully this will kill two birds with one stone.

YouTuber: "You will never own this." PCB reproducer/reverse engineer/general weirdo: "Hold my beer."

Another top notch video from @machonachomedia.bsky.social showing far better than I could what it takes to build your own Sega Neptune youtu.be/PcP60-0NIEw?...

Fun little challenge for SMW veterans: complete the game as small Mario, no power ups or mid-level checkpoints. It's tricky but not as bad as you might expect.

SMTendo + POW Block + @blueshell3d.com NintenDrawer = the ultimate NES of Theseus! Minimal work required: slot the CPU/PPU, solder on power/reset header and install your Power/AV module of choice and you’re good to go! SMTendo and POW Block Coming soon!

Junk DD-10, busted screen, jammed drive mech, horrible gummy coating peeling off... but goodies lurk inside...

Very early steps towards getting the CD hardware working. This is the BIOS diagnostic for the CXD1800 CD decoder chip. The SFC is reading values I have hard-wired onto the CD side of the data bus for testing purposes.

4Gamer 🔗https://www.4gamer.net/games/999/G999905/20250117059/ 海外の技術者がセガの未発売ハード「Sega Neptune」を再現。実際にGenesis/スーパー32X/マスターシステムのカートリッジも動作 基板を作成し，当時の資料をもとに作った筐体に収めた動画も公開され，話題を呼んでいる

So, now that I'm a big-shot YouTuber with over 100 subscribers... I'm thinking about making more videos when I have the time. If there's something you'd particularly like to see, head over to my poll there and let me know (or reply here if you'd prefer). www.youtube.com/@cosam2/comm...

Board now runs under its own power (OK, wrong jack...). RGB video is sorted (no more external RGB amp hack) and audio is there but not 100% yet. No mean feat as A/V is all different to normal SFC or SNES.

Epic warts-n-all write-up on the build process by Neptune pioneer and board tester extraordinaire, Aergan.

Don't get too excited. At the moment this is just the world's most overcomplicated yet incomplete Super Famicom.

Just a little side project: simple tester for Mega Drive/Genesis controllers. github.com/Board-Folk/M...

My Neptune board by @cosam-the-great.bsky.social, Fully working even SMS. I still need to buy the Neptune case for it by dvizix Originally had issues due to me adding 2 wrong resistor values on the pcba, which was messing up the video signal and allowing the 32x side to work 😂

People have been asking how they can support my various projects. I'm not in this for the money but obviously there are costs involved, so I have set up a ko-fi (see bio). Voluntary donations are much appreciated, but please don't expect special treatment in return :)

I really should stop trying to recreate PCBs whenever someone models a case for an unreleased console... @weskmods.bsky.social's fault this time.

Want Your Very Own Sega Neptune? You'll Need A Spare $2,600.