Updating your T-Mobile G1’s Android is a simple, but time-consuming, process. To upgrade, you will normally receive a notification from your T-Mobile G1. In this case, you just need to follow these steps: first, go to the “Settings” menu. Remember to charge your phone during the operation so that your T-Mobile G1 does not turn off during the process. Scroll to “About the device” and click “Update software”. You just have to follow the instructions given by your T-Mobile G1 and wait! This application will update automatically when you are connected to the wi-fi. If it is your applications that are working with difficulty, a system update is not required. This is why we are going to explain how update your T-Mobile G1 apps.
The G1 has 64 MB of room for ROMs, and according to Cyanogen no matter how he tried to squeeze the ROM 64 MB was still 4 MB too small.
So in order to load the new ROM with the eclair goodies, you need to use an SPL (second program loader), to load the ROM.
It's usually also a good idea to leave your phone in a charger during a firmware update so there's less of a chance that you accidentally run out of batteries mid-upgrade and potentially break your phone.
Google periodically pushes out upgrades to the firmware on your Android phone by sending the updated information directly to your cellular or Wi-Fi connection.
danger spl how to at says that the pre-requisites are a rooted G1/Dream phone (check) and a compatible radio, with links to the radio images.
So I downloaded the radios, but nowhere in the rest of the article did it mention what to do with the radio images. Also, some applications are payable, and some are free. Updating the T-Mobile G1 operating system is simple to handle. Do not forget to read the notes and comments of the users in order to judge the effectiveness of the application.Tonight cyanogen is releasing 5.0.7 of the cyanogenmod.This is a modified ROM for android phones, that will finally allow g1 phone users like myself to run most of the latest android apps on our phones.All you need is a Micro SD card to update to the new RC29 firmware.