Mac II Standby Mod

[gonzo]

Hello all,

did some of you ever build a work around for the ugly standby battery in the Mac II's? Did industrially manufactured solutions ever exist which are worth for a replication?

In the case there would be enough space to add a 5V power source (e.g. beside or beyond the harddisk mount) which could be powered from the AC input of the main power supply. Maybe there is even enough space inside the current power supply housing? I did not open it - yet.

The AC-DC converter could be a cheap smart phone USB charger, A DC-DC converter from the China men in ebay would bring down the input to 3,6V, material value < 15€ / $. 

BTW: how do the power buttons on the ADB keyboards work?

Greetings

Florian

 

[Juror22]

From the solution that you posted, were you just wanting something more user friendly than the original soldered in batteries, like there were in this thread? 

https://68kmla.org/forums/index.php?/topic/22866-mac-ll-battery-adapter/

Or something entirely without batteries?

 

[Floofies]

The ADB hardware spec distinctly reserves a whole pin on the Mini-DIN for sending that "power on" signal. Pin 2, I believe. That pin is connected directly to the PSU, no software interprets it at that point, so it's a pure hardware power-on button.

 

[gonzo]

Hi,

I wanted something without batteries. My motherboard already has this dual battery circuit with an extra cpacitor.
But it's good to know that the batteries are switched in series.

Is the PWRON pin on ADB switched against ground our +5V for powering the system on?

Greetings

Florian

 

[gonzo]

Hi,

I finally did the mod. I added a Samsung USB wall charger into the case of the power supply and added two additional wires which connect to the batteries on the motherboard. I don't care for the clock batteries, no machine in my collection has them because I'm too afraid to loose one again because of battery acid. The 5V is OK for powering up the Mac.

This way was fully reversible, I did not have to drill or even cut a wire.









Greetings

Florian