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As I have been looking at the Macintosh Portable in more depth. I've run across a couple of pieces of technical information that may be valuable to other developers. PRAM The original Macintosh computers (128, 512) had 20 bytes of PRAM (parameter RAM). This battery-preserved memory stored a...

That's good news. At least it isn't a hardware issue.

I do use the Desktop Mgr extension (to not have the desktop rebuilt when switching between 6 and 7). I don't think that is a cause. But, who knows.

I reduced my system down to a floppy disk and verified that it sleeps when booted from a FloppyEMU. The .dsk is attached. It is not actually a .hex. I added that to allow it upload to the forum page. Download and just rename it without the .hex at the end.

I am rewatching your video to see if there is something obviously different about yours.

ZuluSCSI Compact RP2040 Lead acid. Battery 50-60% full based on battery desk accessory. No modem installed. October 2023 Androda Portable RAM card 5 MB (no jumper lead or special option). So, 5 MB total (1MB motherboard + 4 MB card). Finder running only (not Multifinder) Backlight...

I can confirm the same. Backlit Portable, PowerBook 7.1 control panel, AppleTalk off, power adapter unplugged, maximum conservation. Sleep in about a minute. Weird. On the same machine as above, but booting into 6.0.8. With Portable v1.2 or 1.3, the machine will go to sleep after 1 minute. So...

In System 7.0.1 the patch is located in the System file at 'lpch' #8 @$1206. In System 7.1, the patch is located in the System file at 'lpch' #8 @$11b4. I believe a long-term solution is to write a new init that removes the ROM and/or patch VBL task and replaces it with a custom one from us...

The Macintosh Portable has a certain cachet. It possesses an exquisite keyboard, a crisp screen, and a complete set of ports and slots. Unfortunately, the size, weight, and price were derided at the time of launch. Presently, the challenges of a Portable are: 1. Most cases are cracked due to...

There are a number of modern battery holder choices available to the vintage hobbyist. Someone even recreated the Apple holder: https://www.ebay.com/itm/177348885387?itmmeta=01KF2SFJTSA86H7PVA347YHAFK&hash=item294ad13b8b I tend to solder the standard battery holders directly to the...

Here are more details: https://tinkerdifferent.com/threads/macintosh-ii-iix-battery-holder-daughterboard-analysis.4978/

The Macintosh II and Macintosh IIx originally had soldered-on batteries for retaining parameter RAM memory and the clock. Later versions of the Macintosh II motherboard and all versions of the IIx motherboard had holes and spacing to accept batteries holders directly. (You can use these holes...

Your comment was thought provoking. So, I just did an investigation and measured it. The problem with that capacitor is that it is wired across both batteries, but only one battery powers the PRAM/clock chip. If you replace each battery individually (leaving the other battery in place), then...

I picked up what I thought was the low-power + EMI filter Portable (or PowerBook) mouse. Indeed, it has the extra long connector. The inductance of the cable wires are 1.8 uH on the standard cable and 2.8 uH on the longer connector. However, upon opening the mouse, I discovered that the...

That's a reasonable conclusion and would not be unusual. However, I've noticed that the IIfx can be very fiddly with memory slots in its old age. I've taken out and then immediately reinserted the memory sticks a couple of times in order to get them working again. It seems like the slots or...

Digging around in the ROM and source code, Apple originally planned to include removable disk cards on the Macintosh Portable. This would have predated PCMCIA cards. In the source file, EDiskDriver.a, Gary Davidian ("GGD") appears to have begun work on EDisks around June of 1988. He first...

That will save so much time and annoyance for a problematic compact Mac. Thank you for sharing.

A couple of curiosities I picked up -- APS SCSI Power Plug II. I assume these allow you to 'hot swap' or 'hot power' SCSI devices. Insides pictured below: X1 is a 5 MHz crystal. U11 is a MAX632 step-up voltage regulator L1 is an inductor needed by the MAX632. U8, U13 are 74HC00A NAND logic...

Those are ceramic capacitors, which are non-polar. That's why there aren't any +/- markings. However, the capacitors there are supposed to be 47 uF. There is no way those tiny capacitors have that much capacity. So, you should replace them. Here are all the locations and expected values...

Wonderful! Congratulations.