Anybody happen to have a Mac Quadra 700/900/950 and willing to run a simple Apple Sound Chip tester app I made and tell me the results? I'm curious about the behavior of the EASC. I'm trying to improve emulator behavior, but I don't have any of those models to test. github.com/dougg3/ASCTe...

GitHub - dougg3/ASCTester: Tester program for the classic Mac ASC chip

Tester program for the classic Mac ASC chip. Contribute to dougg3/ASCTester development by creating an account on GitHub.

github.com

I used Apple's ROM diagnostics to find a broken RAM trace on my Performa 450 after the chimes of death. Pretty nifty! www.downtowndougbrown.com/2025/12/find...

The Fastest (68k) Macintosh Might Not Be an Amiga Anymore

The Fastest (68k) Macintosh Might Not Be an Amiga Anymore

Hackaday Article

hackaday.com

The bad news: I don't get to share video footage of my IIsi PSU frying. The good news: it's fixed! Even though I wasn't feeling optimistic after the first Q101 and D104 replacement failed, I tried again and it worked. The difference: this time, I didn't try to power it up with the dim bulb tester.

My IIsi power supply is proving to be tricky. I put in a new MOSFET and Zener, and this at least restored it to a state where it doesn’t blow the fuse when I plug it in. Good +5VSB too. Tried to turn it on, and it failed again and something’s shorted again. :-(

This is not a time machine. Blowing the fuse in my IIsi PSU gave me an excuse to finish putting my IIci/IIsi PSU tester into a nice enclosure. Pretty proud of this! First time I’ve made a case like this that wasn’t 3D printed. Although I did need to design and 3D print some internal brackets.

Got out the toaster oven and built up some IIsi PSU daughterboards today. First two test out perfect. The third…I turn it on and kablooey! Visible spark and F101 blows on my power supply. Dang, this is what I was worried about. Hard to test these without risking my PSU. Hope it’s not shot.

If you're getting tired of hearing about my IIsi riser board replica, never fear! It's coming to a close! My design is now live on GitHub. Built with all new components from Digi-Key except the two obsolete ICs. Still deciding how to build/sell them to recoup some costs. github.com/dougg3/iisi-...

GitHub - dougg3/iisi-riser-board: Replica of Macintosh IIsi power supply riser board model AP41S

Replica of Macintosh IIsi power supply riser board model AP41S - dougg3/iisi-riser-board

github.com

Okay, my IIsi riser board replica is looking good. Everything will be uploaded to GitHub shortly, and I'll figure out a way to offer them for sale for convenience. As for the failure: it was a bad solder joint on pin 10 of the chip. @48kram.bsky.social had the closest guess and is the winner!

Built up my first IIsi power daughterboard replica. It looks nice, but it doesn’t work! The power supply immediately shuts off like it’s going into protection. Dang. I did end up with random tiny solder balls here and there from the paste. Could just be a soldering mistake.

Remember my research into the “lost” Performa 550 recovery partition? This hard drive arrived today, and it also has the partition! Even better, all the original Performa software is still on it too. This should hopefully solve the mystery of how the partition was originally created.

I probably won’t get around to building a replica up and trying it in my IIsi until this weekend, but look what arrived today!

Getting closer to trying out my replica design…just waiting on PCBs to arrive.

I'm making some pretty good progress on a Mac IIsi power supply riser board recreation design. With how much effort I've put into understanding the schematics, why not? Plus, having it all in KiCad will make it easier to understand for people going forward.

So I did this yesterday in an effort to fix my IIsi. It works fine, but there's something wrong with the soft power circuit because when I tell it to shut down, I hear the relay click but then it turns right back on. Removing every component and cleaning everything didn't fix it! I'm at a loss now.

Pierre found the Paula Abdul Easter Egg that caused the Power Mac 8100/110 to be delayed back in the day! Apple accidentally left PowerPC Enabler 1.1, the version with the egg, on a Spanish Disk Tools disk. I figured out that the newer 6100/7100/8100 ROM was the key to activating it.

Pierre Dandumont@dandu.be · last yr.

Avec @downtowndougbrown.com on a réussi à trouver comment l'Easter Egg de Maula Abdul fonctionne ! www.journaldulapin.com/2025/07/08/p... www.youtube.com/watch?v=caU3...

Do old hard drives self-lubricate? This 80 MB Quantum drive from a Mac Performa worked, but it made a very loud spinning sound. I just let it run for a while, upside down some of the time. Now it's nice and quiet. The rubber bumper will go bad eventually, but I'm pleasantly surprised.

Finally recapped my store demo unit Performa 410 and got it working...but not without some drama. It gave me the chimes of death. Hooked up a serial cable and got the diagnostics data from it, which said it was an Egret error ($0030). Cleaned the heck out of that part of the board, and it works now!

Un autre Easter Egg découvert dans un Power Mac, avec Paula Abdul www.journaldulapin.com/2025/07/01/e...

I partially reballed this eMMC chip...by hand. No stencil. Just sticky flux, 0.3 mm solder balls, tweezers, a microscope, and a hot air station. Each solder ball was about the size of a grain of sand. Somehow I did it, and it was enough to read out the contents using my T56 programmer!

Ars Technica covered the G3 easter egg story, which is too cool! Pretty funny: a huge chunk of the comments on the article ended up being an off topic discussion about whether punctuation belongs inside or outside of a quote: "secret ROM image." vs. "secret ROM image".

with hints from (Downtown) Doug Brown, we just discovered the trigger for the beige powermac G3's secret ROM image: go to the Memory control panel, set up a RAM disk, reboot to mount it, go Special → Erase Disk and name the volume `secret ROM image` — you'll get a file `The Team` at its root […]

^alex in Libera #mac68k and I discovered a new (we think) Beige Power Mac G3 easter egg! Format the RAM disk with the name "secret ROM image" and it will create a JPEG file called "The Team" inside. @dandu.be had already found the JPEG image in the ROM in 2014, but now we know how to reveal it!

When the green light is red, it's charging. When the green light is green, it's finished.

Had a fun little visitor tonight. “Oh hello, I was wondering if you could show me how to get the Tanooki Suit in World 4-5 of Super Mario Bros. 3”

Oh wow, I forgot I still had this. Unopened Color StyleWriter Pro black ink cartridge. Wonder if it’s all dried up?

Il m'a fallu 6 ans, mais j'ai trouvé la ROM japonaise du Macintosh Plus. Elle n'était pas disponible sur le Net et elle contient une police avec les kanjis directement en ROM, ce qui accélère le démarrage du Macintosh Plus avec un OS japonais. www.journaldulapin.com/2025/05/17/r...

I just shared the story of how back in 2013, I fixed the bug in Basilisk II that caused it to fail with a black screen on Windows Vista and 7. Spoiler alert: it wasn’t Windows’ fault. www.downtowndougbrown.com/2025/05/how-...

I finally found some time to share this drive image of System 7.1P3 from the Performa 410 I bought earlier this year. 7.1P3 was previously undumped. It's not perfect, but I don't think we'll find a perfect restore until someone locates and dumps the Market Software Series Volume 1 CD.

MacintoshGarden Feed@macgarden.bitbang.social.ap.brid.gy · last yr.

Performa 410 original hard drive image (7.1P3) https://macintoshgarden.org/apps/performa-410-original-hard-drive-image-71p3 This is the original System 7.1P3 software bundle recovered from a Performa 410. The computer had been lightly used. All user-created […] [Original post on bitbang.social]