MainframeMonitor
Retro CRT System Monitor
Free · Designed for iPad. Not verified for macOS.
Version 3.0 – our biggest leap yet: Parallel Sysplex, Trace Route with world map, two new retro displays and full support for iPhone Duo.
MAINFRAME MONITOR: Your Device as a Mainframe Console
Mainframe Monitor shows your device's real live data in the style of a 1980s IBM operator console: CPU, memory, storage, battery, network, thermal state and motion. All values come from your device. You also get green phosphor text, scanlines, key clicks and real MVS commands.
REAL DATA, CLASSIC LOOK
• Live CPU load per core, memory, DASD, battery, network and thermal state
• Front panel lamp strip that flickers with the load
• Seismograph as a moving paper strip. Knock on the table!
• Compass, audio output, brightness and refresh rate (ProMotion)
• Motion sensors with pitch, roll, yaw and G-vector
• Capacity planning: battery time remaining and storage forecast
• Session statistics (SMF) with averages and peak values
• Clock with UTC, Julian date and 64-bit TOD register
FIVE HISTORIC DISPLAYS
Press PF5 to switch between green and amber phosphor, the IBM 3279 color terminal, the neon-orange IBM 3290 gas plasma display and the Tektronix 4014 storage tube. Each display has its own effects, from degauss to beam redraw, and a matching app icon.
MVS CONSOLE WITH REAL COMMANDS
In the syslog you enter commands like a real operator: D T, D A,L, D M=CPU, D U,DASD, D NET, D IPLINFO, D ENV, D CAPACITY, D M=MIPS (CPU benchmark) and many more. With PF8, a virtual IBM 1403 line printer prints a status report on continuous paper that you can share as an image.
PARALLEL SYSPLEX
Couple iPhone, iPad and Mac on your local network via Bonjour to form a sysplex. The sysplex panel shows CPU, memory and battery of all devices.
TRACE ROUTE WITH WORLD MAP
PF9 traces the path your data takes to any website. You see every hop with IP, location and round-trip time, plus an ASCII world map of the route. The optional latency panel measures ping, jitter, packet loss and clock drift.
IPL, INTRO AND SCREENSAVERS
At startup the system boots with an authentic IPL sequence. The screensavers show real values too: control panel, tape drives, core memory, punch cards, printer or oscilloscope.
GAMES IN THE COBLIB
Hamurabi, Void Patrol, Snake and Bagels: classics in terminal style.
WIDGETS AND LIVE ACTIVITY
• Widgets for the Home Screen and Lock Screen in three sizes
• Control Center button
• Live Activity in 3270 style on the Lock Screen and in the Dynamic Island
FOR EVERY DISPLAY
The layout adapts to iPhone, iPad, Mac and foldable devices like iPhone Duo, stacked or side by side. With a hardware keyboard, F1 to F12 work as PF keys.
FULLY CONFIGURABLE
Show, hide and reorder panels, or choose a preset: Default, Minimal, Performance, Network or Device. Under PF1, an operator guide in German and English explains every feature.
PRIVACY
No tracking, no ads, no analytics. The app works offline. Network features only start after you agree (message IEA910A), and you can withdraw consent at any time under PF7. The EXT lamp shows you when data goes to the internet.
Note: Job names in the log are simulated. D M=MIPS is an estimate, not an official IBM rating.
Ratings & Reviews
- This app has not received enough ratings or reviews to display an overview.
PARALLEL SYSPLEX
• Couple iPhone, iPad and Mac (to be released soon) on your local network (Bonjour)
• Sysplex panel with CPU, memory and battery of all devices
• New commands: D XCF, D XCF,S,SYS1, RO SYS1 and RO *ALL
• XCF messages show when a system joins or is lost
• Orderly sign-off (quiesce) when a device is locked
NETWORK PRIVACY
• IEA910A notice before the first data transmission
• New overview PF7 > N Network Services with Yes/No/Ask
• EXT lamp indicates internet traffic
• Trace Route also works without location lookup
TRACE ROUTE (PF9)
• Every hop with IP, location and round-trip time
• ASCII world map of the route
• Report printout on virtual continuous paper, ready to share
NEW MEASUREMENTS
• Latency panel: ping, jitter, packet loss, NTP clock drift
• Network: subnet mask/CIDR, DNS servers, 5G/LTE
• Storage: block size and sectors
• Memory: virtual memory, page-in/page-out
• Biometric status of Face ID and Touch ID
NEW DISPLAYS
• IBM 3290 gas plasma in neon orange
• Tektronix 4014 storage tube
• Unique switch effect for each display and matching app icons
AND ALSO
• New interactive IPL sequence
• Historic data center intro
• COBLIB as an ISPF member list with data sheets
• "About Mainframe" with intro film
• Panels grouped by topic
• Expanded operator guide
• New screensaver styles
• And much more...
The developer, Ralf Langhoff, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Location
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Ralf Langhoff
- Size
- 22.7 MB
- Category
- Utilities
- Compatibility
Requires iOS 18.6 or later.
- iPhone
Requires iOS 18.6 or later. - iPad
Requires iPadOS 18.6 or later. - Mac
Requires macOS 15.6 or later and a Mac with Apple M1 chip or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Ralf Langhoff
