ISPF Lab is a browser-based simulator of the IBM z/OS ISPF interface: the Primary Option Menu, option 3.4, member lists and the record-oriented editor with its line commands. A lesson engine watches what you actually do and moves you on when you get it right. Nothing leaves your browser.
ISPF (Interactive System Productivity Facility) is the full-screen interface most people use to work on IBM z/OS mainframes. It runs on top of TSO, the command layer you log on to, and it presents everything as panels: a title, a short message area, an Option ===> or Command ===> line, a body of fields, and a legend of PF keys.
The unusual part is the rhythm. A 3270 terminal is an overtype device: you fill in fields, type one-letter commands next to list entries or over line numbers, and nothing happens until you press Enter. Then the whole panel is processed at once. PF3 ends the current panel and returns to the previous one. Errors appear as a short message in the top-right corner.
Data lives in data sets, not files in folders. A partitioned data set (PDS, DSORG=PO) such as USER01.JCL holds named members: USER01.JCL(HELLO). A sequential data set (PS) is one stream of records. Names are qualifiers separated by periods; the first one, the high-level qualifier, is usually your userid.
ISPF Lab reproduces this interaction model faithfully enough that the muscle memory transfers: the same menus, the same 3.4, the same I, D, R, C/A line commands, the same SAVE and CANCEL, even split-screen mode (PF2 opens a second logical screen, PF9 swaps between them). It is a deterministic simulation with a virtual catalog - not a mainframe connection, and not an IBM product.
ISPF Primary Option Menu INVALID OPTION ◄ short message Option ===> 3.4_______________________________________ ◄ command / option line 0 Settings Terminal and user parameters ◄ protected text 3 Utilities Perform utility functions (you cannot type here) 6 Command Enter TSO or Workstation commands Dsname Level . . . USER01__________ ◄ unprotected field (you type here) F1=Help F3=Exit F7=Up F8=Down ◄ PF key legend
Browsers intercept some function keys, so the lab also shows a clickable PF-key strip under the terminal. Clicking a key performs exactly the same internal action as the keyboard.
Lessons validate what happened in the simulator - events like DATASET_SEARCHED or MEMBER_SAVED and the resulting catalog - so any legitimate ISPF route is accepted. Typing 3 then 4 and typing 3.4 both count.
Inside the lab, type EXPLAIN PDS (or any term) on a command line, or open the Explain drawer, for the full glossary.
The course follows the order and terminology of these free guides. Read them alongside the lessons.
Press 1 on your keyboard, or click the terminal above. Everything - your data sets, your progress - is stored in this browser only. There is no account and no server.