Recent content by David Cook

On @JDW ’s thread regarding the Macintosh Portable (https://tinkerdifferent.com/threads/powerbook-100-170-owners.4811/), he posted a link to a technical note...

PowerBook 100: 25 mm PowerBook 170: 30 mm

I just did a quick test. The original ADB mouse uses 70 mA (64.8 idle). The low-power ADB mouse uses 4.8 mA (4.65 idle). The low-power small black ball ADB mouse uses 5 mA (1.75 idle). The low-power small gray ball ADB mouse uses 4.8 mA (1.57 idle). The Apple Desktop Mouse II are similar to...

Only normal, I'm afraid. I'm interested in learning if the long connector has something special in it.

Oh, and at least two more variations exist: non-low power small light-weight black ball (on the left side of the image below) unusual ball retainer and skid (image below)

Yes. Apple ADB mice in my pile (not counting Apple Desktop Bus Mouse II or later) (5) large heavy gray ball (2) low-power large heavy gray ball (1) low-power small middle-weight gray ball (3) low-power small light-weight black ball If you add in the Portable with a 1" inch connector, then there...

I suspect they learned a lot about power usage when designing the portable. (The Apple IIc was always plugged in, correct?) I'll guess that the order went: 1. Original mouse 2. Portable mouse 3. Hey we figured out how to make low power mice and will need some for our PowerBooks -- let's just...

One of the TIL articles you linked to on your spreadsheet discussed the low power ADB mouse. It has an icon of a circle with a flat top on the label. A quick check of my pile suggests this mouse is common. However, the version with a 1 inch plug seems to be a little less common. Here is an...

I placed a piece of transparency over the screen and marked the corners. I then pulled it off and measured it with a ruler. I am confident in those values (after correcting for mm -> cm)

Yup. It's late. : )

Here are a couple of technical tidbits for you... The Macintosh 128 & 512 had 20 bytes of PRAM. The Plus, Mac II, SE, SE/30, IIx, and IIcx bumped that up to 256 bytes of PRAM. The Portable shipped after all of those, but only had 128 bytes of PRAM. Worse still, Apple did not allocate the bytes...

I'm not sure which laptop the above measurements apply to. I just hand measured and got: Backlit portable: 21.1 mm x 13.1 mm = 5.157 in x 9.778 in = 9.78 in diag = 77 dpi PowerBook 100: 19.15 mm x 12 mm = 7.54 in x 4.72 in = 8.9 in diag = 84.8 dpi

No. The movement is so tiny and so fast you feel no vibration at all. The sound is pretty irritating (chalk on a chalkboard).

Another good use for the scaler is to remove the crusty buildup on the ends of leaky capacitor pads. This stuff does not come off easily with isopropyl or heat. I end up scatching it off with my soldering iron -- decreasing the life of the iron tip. Here is an example on an SE/30 pad: After...

Yes. I socketed the original board. Based on your question, I swapped the original chip back in, and the delay reappears. So, the Sony chip is definitely damaged. The pins are clean. So, it isn't corrosion causing some resistance which might act like an RC delay.