So I put it on my web site. Here is the Handspring Treo TechRef:
Release 0.91: TechRef_Treo_091.zip "Handspring Treo Product Technical Specification and Development Guide"
Release 0.92: TechRef_Treo_092.zip "Technical Reference Guide: Handspring Treo Communicator Family"
Note: I had a hard time finding a usable copy of the Treo TechRef. The first copy I found was a self-extracting archive that failed the self-extract step by displaying the message "Corrupt!" and quitting. The self-extracting archive, TechRef_Treo.exe, was created by an obscure and defunct compression tool called CSRE, the author of which (Mr. David Cross) seems to have disappeared, so no help was available from that quarter. However, I now know that the problem was a missing 0-byte at the end of the TechRef_Treo.exe file (apparently stripped by a WayBack Machine bug).
19 January, 2005
P.S. - I am grateful to Mr. David Burns for helping me find a usable copy of the Handspring Treo TechRef.
The "release 0.92" Treo TechRef is circa 2002, and it covers the Treo 90/180/180g/270. It doesn't cover the Treo 300, but the 300 is very similar to the 270 (but PCS/CDMA instead of GSM), and the pinouts are identical (see p.50 of the TechRef).
Note that the Treo's serial lines are TTL (5v) levels, not RS-232. If you need RS-232 levels then the easiest solution is to buy a Treo serial hotsync cable on eBay.
I hacked a Treo serial hotsync cable to make this connector:
The red wire is RxD (pin 1).
The orange wire is TxD (pin 2).
The black wire is ground (pins 12 & 13).
The circuitry that you see on the little PCB is the TTL/RS-232 voltage level conversion circuit that hides in the connector housing of a serial hotsync cable. That big silver thing in the middle is the hotsync push-button (which should tell you which side of the connector we're looking at in the photo).
For my application I didn't need the RS-232 level translation, so I just cut the traces and used wires soldered directly to the edge connector. (Soldering those tiny connections is challenging, BTW!)
9 May, 2005