Tech by Androda Products

[JDW]

This product does what it says: Mac Portable digital video out port -> 640x480 VGA. Doesn't convert the other way, sorry.

Quick question... The VGA adapter product page says this:

* Please only connect or disconnect this adapter when the Portable is turned off

I assume the above means the following?

* Please only connect or disconnect this adapter when the Portable is Shutdown or disconnected from power, not when merely Sleeping

 

[Androda]

That depends entirely on whether the external 5v video power line is disabled when the Portable is in sleep mode. I would have to check.

It's a switched supply, so if power is cut to the external video pin in sleep mode then it would be safe to remove.

Note that the external video port has a direct connection to battery voltage which is on all the time! I didn't use that supply for this product, instead relying on the switched 5v supply mentioned above.

 

[ClassicHasClass]

Noice!

 

[JDW]

2: The [Portable Battery Eliminator] PCB does contain a provision for a 9v battery holder to be soldered on, but I haven't tried it... This is the BT1 solder points to the right of the supercapacitors, where you would solder the + and - (labeled on the PCB) leads from a 9v battery holder... if there's interest in a PRAM-retaining option I'll check that it works properly.
You are correct that the 9v battery in a Portable is basically the PRAM battery. This is due to where the PRAM values are actually stored (not in a super-low-power RTC chip like most Macs), which requires the main 5.2v rail to be powered on all the time. Can't imagine PRAM battery life is all that great to begin with.

QUESTION #1: As per the above, did you ever check that the 9V battery works properly?

QUESTION #2: So when there is no lead acid main battery in the machine at all, that 9V battery would be keeping the 5.2V rail "powered all the time"? (The same would be true if the AC Adapter cord was yanked out of the Battery Eliminator and the supercaps later drained.)

QUESTION #3: What would happen if you solder a 9V battery connector to those BT1 solder pads, connected a 9V battery, then powered the machine off, put the jumper onto the Battery Eliminator to make sure the super-caps were drained properly and then stored the machine? When you use that little jumper, that only drains the super-caps and doesn't affect the 9V battery from keeping the 5.2V voltage rail at 5.2V?

 

[Androda]

QUESTION #1: As per the above, did you ever check that the 9V battery works properly?

I did not, because of the answer to question #3.

QUESTION #2: So when there is no lead acid main battery in the machine at all, that 9V battery would be keeping the 5.2V rail "powered all the time"?

Correct, the main 5.2v rail is required for PRAM value retention.

QUESTION #3

I do not recommend storing the Portable for any long-term period of time with a 9v battery installed. And thus have decided simply not to support the installation of 9v PRAM batteries. They often leak and cause system damage, similar to electrolytic capacitors leaking over time and corroding things away.

On the rest of your question, there's only one power input to the Portable internally. The battery harness carries power from both the primary lead acid battery and the PRAM backup battery to the system (9v battery has some series diodes to prevent back-charging). So using the discharge jumper would by necessity also drain the PRAM battery.

It is my belief that Apple never intended the Portable to sit unused for more than a month or two, which is my guess on how long a 9v backup battery would last.

 

[Androda]

A new version of the BlueSCSI V2 Centronics 50 Pin is now available:

BlueSCSI V2 Centronics 50 Pin (Shorter) – Tech by Androda

androda.work

Like it says in the URL, this is literally a shorter version of the previous design.
Similar to the smaller DB25, it's over 1cm shorter than the prior version and has termination always-enabled.