Hercules System/370, ESA/390, z/Architecture Emulator Hercules – General Information Version 3 Release 06 Contents Contents ........................................................................................................................................................2 Figures...........................................................................................................................................................7 Tables............................................................................................................................................................9 1. Preface .............................................................................................................................................10 1.1 Edition information ........................................................................................................................10 1.2 What this book is about.................................................................................................................10 1.3 Who should read this book ...........................................................................................................10 1.4 What you need to know to understand this book..........................................................................10 1.5 How to use this book.....................................................................................................................10 1.6 Revision Notice .............................................................................................................................10 1.7 Readers Comments ......................................................................................................................11 1.8 Legal Advice..................................................................................................................................11 1.9 Trademarks ...................................................................................................................................11 1.10 Acknowledgements ...................................................................................................................12 2. Related Publications.........................................................................................................................13 2.1 Hercules Emulator – General Information ....................................................................................13 2.2 Hercules Emulator – Installation Guide ........................................................................................13 2.3 Hercules Emulator – User Reference Guide ................................................................................13 2.4 Hercules Emulator – Messages and Codes .................................................................................13 2.5 Hercules Emulator – Reference Summary ...................................................................................13 3. Hercules Emulator Overview ............................................................................................................14 3.1 Introduction ...................................................................................................................................14 3.2 History of Hercules Development .................................................................................................17 3.3 Production use of the Hercules Emulator .....................................................................................18 3.4 Hercules Executables ...................................................................................................................18 3.5 Hercules Source Code..................................................................................................................18 4. Implemented Features......................................................................................................................22 4.1 Implemented architectural standard features ...............................................................................22 4.2 Implemented architectural optional features.................................................................................22 4.3 Implemented optional features of z/Architecture ..........................................................................24 4.4 Not yet implemented optional z/Architecture features ..................................................................25 4.5 Not yet implemented standard features........................................................................................25 4.6 Partially implemented optional features........................................................................................25 4.7 Not yet implemented features.......................................................................................................25 4.8 Compliance ...................................................................................................................................26 4.9 Related Products and Tools..........................................................................................................26 5. Emulated Device Types....................................................................................................................27 5.1 Local non-SNA 3270 Display or Printer ........................................................................................27 5.2 Console Printer-Keyboards...........................................................................................................27 5.3 Card Readers................................................................................................................................28 5.4 Card Punch ...................................................................................................................................28 5.5 Line Printers..................................................................................................................................28 5.6 Tape Drives...................................................................................................................................29 5.7 Channel-to-Channel Adapters ......................................................................................................32 5.8 FBA Direct Access Storage Devices.............................................................................................33 5.9 CKD Direct Access Storage Devices............................................................................................33 5.10 Communication Lines................................................................................................................34 6. CCKD Compressed CKD DASD Devices ........................................................................................36 6.1 CCKD Introduction ........................................................................................................................36 6.2 CCKD Shadow Files .....................................................................................................................36 6.3 Compressed DASD File Structure ................................................................................................37 6.4 How it works..................................................................................................................................40 7. Shared Device Support ....................................................................................................................42 7.1 Usage of Shared Devices .............................................................................................................42 7.2 Caching .........................................................................................................................................43 Hercules Emulator – General Information Page 2 7.3 Compression.................................................................................................................................43 7.4 Technical Approaches ..................................................................................................................44 7.5 Protocol .........................................................................................................................................44 8. SCSI Tape Drives.............................................................................................................................49 8.1 Basics............................................................................................................................................49 8.2 Special Options.............................................................................................................................49 9. Hercules Dynamic Loader ................................................................................................................51 9.1 Dependency Section.....................................................................................................................51 9.2 Registration Section......................................................................................................................52 9.3 Resolver Section...........................................................................................................................52 9.4 Device Section ..............................................................................................................................52 9.5 Final Section .................................................................................................................................52