Following are some of the questions I get most often, and their answers. I’ve tried to group them into logical sections, but they may be in no particular order.

Please note: I have only had experience with Handspring’s Visor Deluxe. I have never used, handled, touched, or seen in person, any other Visor, and cannot answer questions about them.

What is the Pinout of the Visor Connector?

With the Visor screen up and the buttons at the bottom, pin 1 is on the right-hand side. The pinout is as follows:
1. RX Data (Serial)
2. Keyboard Detect
3. Hotsync Interupt
4. Ground
5. USB + Data
6. USB – Data
7. VDOCK (Cradle Power)
8. TX Data (Serial)

Please note this is applicable for Visor Deluxe only! If it works for any other Handspring product that is strictly coincidental.

Can you send me Circuit Diagrams / Schematics for the Visor?

A) I have never had access to the circuit diagrams / schematics for the Visor. It would have made my life a LOT easier, let me tell you. B) What documents I did get (lots of stuff used to be available from Handspring’s website) is all copyrighted and I can’t distribute it. Sorry. C) Even if I could share what info I did get, it’s all archived somewhere on a CD and I don’t have time to go looking for it. So sorry, the answer is no.

Is the battery modification safe?

Safe is a relative term. The modification *seems* to be ok. If it is done correctly by someone who is competant and experienced with soldering, and who understands the process, then there should not be any trouble. On the other hand, if done by someone who has never soldered before, doesn’t know which end of a diode is which, and is trying to duplicate what is seen in the pictures and hope for the best, then no, it is not safe. 
The modifications will most deffinately void your warranty. 
I do not guarranty, warranty, or otherwise claim you will not kill your Visor. Re-read the warning and disclaimer. 
On the other hand, from an electronic theory point of view, if done right, there is no reason why it should not work fine.

Does the battery modification have protection for over-charging? How is the charging controlled?

The charging is done by trickle-charging. The batteries are fed a relatively low current. There is no circuitry to monitory them, or to tell when they are full. Fancy battery chargers with such control, tend to use high current to fast-charge batteries, then drop to a trickle-charging mode when the batteries are full. My mod is trickle-charge only. I’ve left the Visor in the cradle for over 24 hours, with no ill effects. If you are worried about some malfunction drawing too much current, this is taken care of by the USB hub. Powered hubs provide a maximum of 500 mA to each port. If the cradle draws more than 500mA the hub shuts that port down. Computer USB ports *probably* work the same. I have always used a hub though, so I cannot say for sure.
If you aren’t comfortable with this, then don’t do the mod. Read the warning and disclaimer again.

Will the mods work with my Visor Platinum / Prism / Etc?

I have never worked with anything other than a Visor Deluxe. I happen to know that the only difference between the Deluxe and the Solo is that the Deluxe has more memory. Therefore I know that it will work with the Deluxe and the Solo. I cannot help you with any other Handspring product.

Can I use NiCd or NiMH batteries, instead of Rechargable Alkelines?

You can do anything you like. I don’t know how NiCd or NiMH batteries will perform, so back-up often. My research suggested that rechargable alkelines were the best bet for what I wanted to achieve. Your mileage however, may vary.

How long will a set of rechargable batteries last?

I wish I had a good answer for this one. In my case, the batteries lasted pretty much through the life of the Visor, until I shelved it. I would estimate that 2 or 3 months at minimum, if you top up the charge regularily.

Will the mods work with my 3rd party cable / cradle for other Handspring models?

As noted above: I Don’t Know.

I heard of a mod to increase RAM / change RAM into Flash, can you help?

No. I have looked into the possibilities of increasing RAM, but it is beyond my capabilities to figure out how to do it. The Visor cannot be modified to use Flash instead of RAM. It has different electrical characteristics so it isn’t ‘drop-in replacable’, and the Palm OS treats Flash as ROM anyways so it won’t let you save anything. 

Have you ever heard of a Springboard module that does xxxxx?

Probably not, I’m afraid. I have not been active with Handspring’s products for about a year. I know there were a lot of nifty modules planned, I don’t know what was made. Visit Handspring’s web site, they have a page that gives info on new springboards.

Do you know about software to do xxxx?

Nope. Again, I have been away from the Visor, and the Palm OS, for about a year. I never learned how to write software for them. Try www.palmgear.com or Tucows.

I’d like to modify my springboard module xxx so that it does xxxx. What do you think?

I like to encourage experimentation. A little knowledge can be dangerous, but I learn-by-doing and like to see other people learn the same way. I cannot help you with your individual project, other than with moral support: Good luck, go for it, and have fun! When I did my first Visor modification, I knew that I might end up with a $300 paperweight. Be aware that when you pop the top and go in with the soldering iron, you might fry / kill / destroy something. That is the risk. If the desired outcome is worth the risk, or the learning experience worth the risk, then do it! Read the warning and disclaimer again.

Why did you stop using the Visor?

I found out that Apple’s Newton was better. Sure, it was discontinued in 1998. It was way ahead of it’s time then, and it still has better hardware, a better OS, and a better User Interface than any PDA on the market. 
Think, cancelling the Space Shuttle, and focusing on the Wright Flyer. Yes, that is a bit of an exageration, but when the Palm Pilot had a teeny screen and a 16MHz processor and you had to write in a tiny little box at the bottom of the screen, the Newton had a big screen, a 162 MHz processor, and you wrote where you wanted your text to appear. And it learned to adapt to your handwriting, rather than you having to learn a new way to write. 
Oh wait, they still sell 16MHz Palm OS devices, with teeny screens, and you still have to learn a new way to write, and keep it down in a little box at the bottom.