[NTLK] Newton & USB Connectivity

[Matthias Melcher]

On 06.03.2011, at 08:04, Bradley Loeding wrote:

> I thought I'd share this:
> FTDI Chip has been discussed on the list before, they specialize in small
> USB bridge IC products, and have virtual COM port drivers for just about any
> major operating system.
> 
> What I didn't see talked about before were their cable assemblies. They've
> got ready to splice RS422 to USB cables with the IC built right inside the
> molded plug. If you can cut and splice wire, you should be able to easily
> add USB support to a Newton.
> 
> http://www.ftdichip.com/Products/Cables/USBRS422.htm
> 
> This item is well stocked and can be ordered from Digi-Key, Mouser, etc. for
> around $35. Makes for a very clean USB connection to the MP2x00, assuming
> you've got an interconnect adapter or equiv. No need to open the case and
> add a board.

Well, yes, I am very well aware of those. But as you can see, the important plug on these is missing: the MessagePad plug. For the first round of models, this would be a mini Din plug that requires an additional pin. These are pretty hard to solder by hand. The cost would be $35 + $2 plus whatever time you need to invest to get a secure connection. The later MessagePad models have the interconnect port. These plugs are extremely rare and JAE will not make them again (I offered to buy their minimum  run of 600, but the declined). These not cost $15 in single quantities if you are lucky enough to find them. I have seen them offered for $40 - yes, that is the plug only!

An internal board on the other hand can use a standard USB or USB Mini plug with cables available for cents everywhere. The internal adapter is available for $4 and allows even for charging via USB. Using a ini USB there is even enough room for a headphone plug on the underside of the PCB, and while we are at it, we could leave room on the PCB for a bluetooth chip. The internal board can alos solve the issue with "slowdown" on MSWindows machines by reducing the transmission speed wherever the DMA hiccup appears.

The USB-001 board is probably a much better solution than a cable.

 - Matthias