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To avoid hijacking your thread on the PowerBook, I've updated my journey to find the Portable mouse here: https://tinkerdifferent.com/threads/black-ball-adb-mouse-serial-numbers-and-portable.5047/

@JDW posted some interesting Apple TIL articles back on thread regarding the PowerBook 100 and 170. One of those articles refers to the 'low power' mouse and EMI shielding in a long ADB connector. I located one of those mice, but the cable was disconnected, so I wasn't confident it was really an...

FYI. On early Macintosh II motherboards, some engineer got overzealous with the ground loop. They connected pin 1 to pin 4/7 GND. I assume early oscillators did not use pin 1. However, most of the oscillators I know use pin 1 for 'enable'. If it is grounded, it won't output. Therefore, if you...

A couple of things I forgot on my original post. 1. Someone added an FPU. That's nice. 2. But, they only added two 1 MB sticks of memory. Why not at least 2 MB sticks?

Just got lucky on eBay. The moment I saw no label I clicked 'Buy It Now'. The seller said "Wow, I just listed that."

I just picked up a pre-release Color Classic. Notice that it is missing the word "Macintosh" beneath the Apple logo, the words "Color Classic" on the bottom plastic insert, and the QuickTime sticker on the lower right. The plastic has not yellowed. Looking closer, there are no signs that the...

Gorilla 5 minute epoxy clear. I can't find a product number, though. https://amzn.to/4ad4YlZ

Yes. That's it.

A while back, I picked up a loose Macintosh II motherboard for the sole reason that it contained the rare (not valuable, but rare) recalled Macintosh II ROMs. These ROMs contain a bug that prevents NuBus cards from accessing more than 1 MB of NuBus space. However, the board itself was trash...

I am seriously considering replacing the serial diagnostic in the ROM with something better suited for the problems we encounter. I would just patch the start of the existing code to jump to the end of ROM (where I assume there is plenty of free space). This would be particularly useful for the...

Wow! Thank you very much. You've made my day.

The other day, I posted about repairing some Macintosh II motherboards. https://tinkerdifferent.com/threads/macintosh-ii-advanced-diagnostic-techniques.5020/ Two of the 'dead' motherboards had bad 31.3344 MHz oscillators. I thought it would be interesting to open up the oscillators and try to...

I was unaware of that. Thanks for taking the time to explain.

Here is a better look at the Portable battery input connector (J17) on the motherboard. Like other power connectors (such as on the Macintosh II, IIcx, or LC series), the ground inputs are actually connected together on the PCB itself. However, unlike other power connectors, the +V inputs are...

Also, is this needed for both the backlit and non-backlit?

Really? I could just throw the tst instruction into the Quiet Portable init if that's all it is. So, does that completely eliminate the slowdown when using 7MB of memory, or just the additional penalty after waking from sleep?

Given the difficulty of finding non-surface-mount parts, I got the impression this was just a hobbyist exercise, rather than commercial or a replacement. Maybe I misunderstood the purpose of this project. I agree that it isn't fair to distribute copies of Steve's proprietary IP. However, I also...

The Macintosh II computer motherboard revision 820-0228-A is the most common. Unfortunately, it is the most corroded due to using many more surface-mount electrolytic capacitors. Nearly all of the repair work is located around these leaky capacitors. The techniques described in this post are...

I regret reusing an old hard drive cable for this photo -- as the color of the wires is confusing when used on a Portable. Give me a minute and I'll upload a better diagram.

I am so glad you said that, because that's what I had to do to get the Portable to not crash when playing sounds. I was embarrassed to post my 'hack' because I felt it wasn't a solution. But, given how many Portables you've worked on, and given that Apple disabled this in the backlit model, it...