IPSW Downloads

iOS 4.2.1 - 8C148a for iPhone 3GS

This firmware is not signed. This means you cannot restore to it in iTunes.

Release DateInvalid Date
Upload Date21 November 2010
File NameiPhone2,1_4.2.1_8C148a_Restore.ipsw
File Size0.39 GB
SHA256sum09f3617fcf3e419e12c4a3c62f1fe0ab3909d0573a00937584124f869a7df15d
MD5sumd688d2d48c8b054367adef8e7ab4f5ea
SHA1sum2787bb9fbf18594279d05682e6fd16d2b9612a2a
IdentifieriPhone2,1

Installation Instructions

Windows

  1. Install the latest version of iTunes from the Microsoft Store.
  2. Connect your iPhone 3GS to your PC.
  3. Open iTunes and navigate to your iPhone 3GS.
  4. Hold the Shift key and click "Restore".
  5. Select the iPhone2,1_4.2.1_8C148a_Restore.ipsw file you downloaded.
  6. Wait for the restore to complete and for your iPhone 3GS to reboot.

macOS

  1. Connect your iPhone 3GS to your Mac.
  2. Navigate to your iPhone 3GS in Finder.
  3. Hold the Option or Alt key and click "Restore".
  4. Select the iPhone2,1_4.2.1_8C148a_Restore.ipsw file you downloaded.
  5. Wait for the restore to complete and for your iPhone 3GS to reboot.

Linux

  1. Install idevicerestore.
  2. Connect your iPhone 3GS to your PC.
  3. Open a terminal and navigate to the IPSW file you downloaded, e.g., cd ~/Downloads.
  4. To perform a full erase restore, type idevicerestore -e iPhone2,1_4.2.1_8C148a_Restore.ipsw and press Enter.
  5. Wait for the restore to complete and for your iPhone 3GS to reboot.