First, the iPhone uses a specially customized Mac OS X operating system. At the beginning of the release, my own system version was 1.0.2. Later, I corrected the errors in the lower version through firmware update and introduced new functions. The firmware of IOS version 4.2 has new functions. The genuine version number of IOs version 4.2 is 8C 148, and it supports iPhone 4/3GS/3G, iPod Touch and iPad. Among them, the upgrade contents of iPhone and iPod Touch include:

1, AirPrint. Print e-mail, photos, web pages and other content directly on the AirPrint compatible printer in the local wireless network.

2, AirPlay. wirelessly stream videos, music and photos to Apple V, and wirelessly stream music to AirPlay-compatible speakers or receivers, including AirPort Express.

3.FaceTime has been improved. Use voice control to make calls, make calls via SMS, and support Bluetooth accessories.

4. Find the text in the webpage through Safari.

5. A new font has been added to "Memo"

6. Add text ringtones of SMS/MMS, and set customized ringtones for each contact.

7. More available access restrictions (parental control): account setting, application deletion, friends in the game center, location setting.

8. It can be imported. Ics file into the calendar.

9. Support mixed input of Roman letters and simplified Chinese.

Second, iOS 4.2 for iPad includes the following functions:

1, which supports multitasking of third-party applications. The user interface allows multitasking, and can quickly switch between applications, adjust screen brightness, control playback, lock screen rotation and manage print tasks. Support audio applications to play in the background. VoIP applications can receive incoming calls in the background or sleep state and keep talking. Applications can monitor locations and take action while running in the background. You can use push and local notifications to push reminders and emails to applications that can complete tasks in the background.

2. Use folders to better organize and access applications.

3, mail improvement. Unified inbox, displaying all accounts' emails in one place. Inbox switching is fast, and you can quickly switch between different email accounts. Organize e-mails by subject so that multiple e-mails can be displayed in the same conversation. Import a. Ics file into the calendar. You can choose the size of the photo attachment by using a compatible third-party application to open the attachment archive or delete the search results. You can edit or delete messages in your Outbox.

4. Game center. Send and receive invitations to make friends. Invite friends to join multiplayer games through the internet. Play multiplayer games with other automatically matched players. Check leaderboards and achievements, and discover new games from friends.