Release appearance
iOS 4.0.1 Public
Recorded context
About this appearance
The surviving Apple record establishes iOS 4.0.1 as the predecessor to iOS 4.0.2 and separately describes a planned signal-bar formula correction, but it does not explicitly connect that correction to the 4.0.1 package.
- Date
- Jul 15, 2010
- Availability
- available
- Revision
- No
Release notes
What changed
Original editorial synthesis. Linked references appear with the claims they support and in the source ledger.
Apple announced in early July that its signal-strength display formula could show too many bars. It planned a free software update using a revised calculation and larger lower bars, without changing the underlying radio signal.[1]
Apple’s later iOS 4.0.2 advisory names iOS 4.0.1 as an affected predecessor, confirming that the version existed. Neither reviewed page names iOS 4.0.1 as the delivery vehicle for the earlier plan, and Apple’s 2010 security index does not list a 4.0.1 security release, so the linkage remains explicitly partial.[2][3]
Source ledger
References
Sources are linked to the claims they support. Publication and access dates are shown when available.
- Letter from Apple Regarding iPhone 4
Apple Newsroom · 2010-07-02T00:00:00Z · Signal-bar finding and planned software update
- About the security content of the iOS 4.0.2 Update for iPhone and iPod touch
Apple Support · 2026-07-30 · Available for range through iOS 4.0.1
- About the security content of the iOS 4.0.2 Update for iPhone and iPod touch
Apple Support · 2026-07-30 · iOS 4.0.1 identified as prior installed version
- Letter from Apple Regarding iPhone 4
Apple Newsroom · 2010-07-02T00:00:00Z · Planned signal-display software correction
Release changes
Changed in this release
Features, fixes, removals, and regressions first observed in this release record.
bugFix · fixed
Signal-bar display correction with incomplete version linkage
The intended change was to make displayed bars better reflect existing signal strength and enlarge the lower three bars. Attaching it to this route is marked partially documented because Apple’s statement predates the package and omits its version number.
- [1] About the security content of the iOS 4.0.2 Update for iPhone and iPod touch · iOS 4.0.1 identified as prior installed version
- [2] Letter from Apple Regarding iPhone 4 · Planned signal-display software correction