VisorCentral.com (http://discussion.visorcentral.com/vcforum/index.php)
- Visor Edge (http://discussion.visorcentral.com/vcforum/forumdisplay.php?forumid=25)
-- The Edge Connector (http://discussion.visorcentral.com/vcforum/showthread.php?threadid=12903)

First impressions.

I was able to grab a copy of the "Handspring Product Guide: Visor Edge" technical documentation. From it I did a very quick comparison between the Springboard connector and the Edge Connector. Here is what I found.

• Both have 68 connectors. However the two are ordered differently.
• The Springboard has 9 connectors that are marked as "Not Connected" while the Edge has only 1 connector that is marked as "Reserved".

• CTS2 - Clear To Send 2
  CTS2 is connected directly to the second UART on the DragonBall VZ processor. It is not buffered and
  appropriate care should be taken when using this signal. This signal is not present in the Springboard Expansion
  Slot.
• PASSTHROUGH [1:4] - Pass Through
  These pins are passed through the Cradle Interface to the Edge Connector. They are intended for future peripheral use and are presently reserved. These signals are not brought out in the Detachable Springboard Slot.
• RTS2 - Request To Send 2
  RTS2 is driven directly from the second UART on the DragonBall VZ processor. It is not buffered and appropriate care should be taken when using this signal. This signal is not present in Springboard Expansion Slot.
• RXD2 - Receive Data 2
  RXD2 is connected directly to the second UART on the DragonBall VZ processor. It is not buffered and appropriate care should be taken when using this signal. This signal is not present in the Springboard Expansion Slot.
• TXD2 - Transmit Data 2
  TXD2 is driven directly from the second UART on the DragonBall VZ processor. It is not buffered and appropriate care should be taken when using this signal. This signal is not present in Springboard Expansion Slot.

Idea. One of the complaints about the Visor line has been the lack of flow control lines for the serial port on the HotSync connector. The Edge connector includes a second serial port with flow control lines (RXD2, TXD2, CTS2, RTS2) and four pass through lines to the HotSync connector (PASSTHROUGH[1..4]). Therefore one could build a very simple device, which attaches to the Edge connector that connects the serial port lines to the pass through lines. This would then give you a serial port with flow control on from the HotSync connector. However, it would still have the other disadvantage of the Visor serial port, TTL instead of RS-232 voltage levels. On could go further and put a RS-232 line driver powered by Vcc to fix this. However if one is going to do that, one might as well not use the feed back line, but instead provide a standard DB-9 connector.