Going AIPS: A Programmer’s Guide to the NRAO Astronomical Image Processing System Version 15 April 90 VOLUME 1 ABSTRACT This manual is designed for persons wishing to write programs using the NRAO Astronomical Image Processing System (AIPS). It should be useful for a wide range of applications, from making minor changes in existing programs to writing major new applications routines. All basic aspects of AIPS programming are dealt with in some detail. AIPS programmers: Bill Cotton — Image construction and applications routines Phil Diamond — Spectroscopy Chris Flatters — Polarization and VLBI Eric Greisen — TVs and AIPS Kerry Hilldrup — UNIX and Cray COS implementations Gareth Hunt — Data formats Bill Junor — VLBI Glen Langston — Imaging Nancy Maddalena — I^Tjjpt conversion C ontents 1 Introduction 1-1 1.1 Scope ..........................................................................................................................................................1-1 1.2 Hey You, Read T h is................................................................................................................................1-1 1.3 Philosophy ................................................................................................................................................1-2 1.4 An Overview of the AIPS System..........................................................................................................1-2 1.4.1 T asks.............................................................................................................................................1-3 1.4.2 V erbs.............................................................................................................................................1-3 1.4.3 Data Files.......................................................................................................................................1-3 1.4.4 I/O ................................................................................................................................................1-3 1.5 Style.............................................................................................................................................................1-4 1.5.1 Precursor Comments...................................................................................................................1-4 1.5.2 Body Comments..........................................................................................................................1-5 1.5.3 Indentation....................................................................................................................................1-5 1.5.4 CONTINUE Statements.............................................................................................................1-6 1.5.5 Statement Numbers....................................................................................................................1-6 1.5.6 Blanks.............................................................................................................................................1-6 1.5.7 Modular Code .............................................................................................................................1-6 1.5.8 Portability ....................................................................................................................................1-6 1.6 Language...................................................................................................................................................1-7 1.6.1 FORTRAN....................................................................................................................................1-7 1.6.2 Statement O rder..........................................................................................................................1-8 1.6.3 INCLUDES....................................................................................................................................1-8 1.6.4 Dimension Declaration................................................................................................................1-9 1.6.5 SAVE Statements .......................................................................................................................1-9 1.7 Documentation..........................................................................................................................................1-9 1.7.1 User Documentation ................................................................................................................1-9 1.7.2 Programmer Documentation ....................................................................................................1-10 2 Skeleton Tasks 2—1 2.1 Data Modification Tasks — FUDGE and TAFFY.............................................................................2-1 2.1.1 FUDGE..........................................................................................................................................2-2 2.1.2 TAFFY..........................................................................................................................................2-4 2.2 Data Entry Tasks (UVFIL and CANDY) ..........................................................................................2-7 2.2.1 UVFIL ..........................................................................................................................................2-8 2.2.2 CANDY..........................................................................................................................................2-11 2.3 Modifying a Skeleton Task.......................................................................................................................2-13 3 Getting Started — Tasks 3—1 3.1 Overview ...................................................................................................................................................3-1 3.2 The Cost of Machine Independence.......................................................................................................3-2 3.2.1 Character Strings..........................................................................................................................3-2 3.3 Task Name Conventions..........................................................................................................................3-3 i 3.4 Getting the Parameters.........................................................................................................................3-3 3.4.1 In AIPS (Help file)......................................................................................................................3-3 3.4.2 At Task Startup (GTPARM)...................................................................................................3-5 3.4.3 While a Task is Running (GTTELL)......................................................................................3-5 3.5 Restarting A IPS......................................................................................................................................3-6 3.6 INCLUDE files.........................................................................................................................................3-6 3.7 Initializing Commons...............................................................................................................................3-7 3.7.1 Device Characteristics Common ............................................................................................3-7 3.7.2 Catalog Pointer Common.........................................................................................................3-8 3.7.3 History Common.........................................................................................................................3-9 3.7.4 TV Common...............................................................................................................................3-9 3.7.5 UV data pointer common.........................................................................................................3-9 3.7.6 Files common, DFIL.INC.........................................................................................................3-9 3.8 Input and Output File Names...............................................................................................................3-10 3.9 Copying Extension Files.........................................................................................................................3-10 3.9.1 History.........................................................................................................................................3-10 3.9.2 Extension tables (ALLTAB, TABCOP) ................................................................................3-11 3.10 Communication with the user...............................................................................................................3-11 3.10.1 Writing messages.........................................................................................................................3-11 3.10.2 Turning off system messages ...................................................................................................3-12 3.10.3 Writing to the line printer.........................................................................................................3-12 3.10.4 Writing to the Terminal (ZTTYIO) ......................................................................................3-13 3.11 Scratch F iles............................................................................................................................................3-14 3.12 Terminating the Program......................................................................................................................3-15 3.13 Batch Jobs ...............................................................................................................................................3-16 3.14 Installing a New Task ............................................................................................................................3-16 3.15 INCLUDES...............................................................................................................................................3-16 3.15.1 DDCH.INC...................................................................................................................................3-16 3.15.2 DFIL.INC......................................................................................................................................3-17 3.15.3 DMSG.INC...................................................................................................................................3-17 3.15.4 DUVH.INC...................................................................................................................................3-17 3.15.5 PUVD.INC...................................................................................................................................3-18 3.16 Routines......................................................................................................................................................3-18 3.16.1 ALLTAB ......................................................................................................................................3-18 3.16.2 CHCOPY......................................................................................................................................3-19 3.16.3 CHCOMP......................................................................................................................................3-19 3.16.4 CHFILL.........................................................................................................................................3-19 3.16.5 CHLTOU......................................................................................................................................3-20 3.16.6 CHMATC......................................................................................................................................3-20 3.16.7 CHR2H.........................................................................................................................................3-20 3.16.8 CHWMAT...................................................................................................................................3-20 3.16.9 D IE ...............................................................................................................................................3-21 3.16.10 DIETSK.........................................................................................................................................3-21 3.16.11 EXTCOP......................................................................................................................................3-21 3.16.12GTPARM......................................................................................................................................3-22 3.16.13GTTELL.................................................................................................................................. 3-22 3.16.14HIADD.........................................................................................................................................3-23 3.16.15HIADDN......................................................................................................................................3-23 3.16.16HIAD80.........................................................................................................................................3-23 3.16.17HICLOS.........................................................................................................................................3-23 3.16.18HIINIT.........................................................................................................................................3-24 3.16.19HIMERG......................................................................................................................................3-24 3.16.20HIREAD......................................................................................................................................3-25 3.16.21 HISCOP.........................................................................................................................................3-25 li 3.16.22H2CHR..........................................................................................................................................3-25 3.16.23MAKOUT ...................................................................................................................................3-26 3.16.24PRTLIN..........................................................................................................................................3-26 3.16.25 PSFORM.......................................................................................................................................3-27 3.16.26RELPOP.......................................................................................................................................3-27 3.16.27SCREAT.......................................................................................................................................3-27 3.16.28TABCOP.......................................................................................................................................3-28 3.16.29UVPGET.......................................................................................................................................3-28 3.16.30ZDCHIN .......................................................................................................................................3-29 3.16.31 ZTTYIO .......................................................................................................................................3-30 4 The AIPS Program 4-1 4.1 Overview ...................................................................................................................................................4-1 4.2 Structure of the AIPS Program.............................................................................................................4-1 4.2.1 The POPS processor....................................................................................................................4-2 4.2.2 POPS commons..........................................................................................................................4-4 4.2.3 TAG and T Y PE..........................................................................................................................4-7 4.2.4 Error Handling.............................................................................................................................4-8 4.2.5 Memory Files .............................................................................................................................4-9 4.2.6 Special modes................................................................................................................................4-9 4.3 Example of the POPS processor.............................................................................................................4-10 4.3.1 The Compiler................................................................................................................................4-10 4.3.2 The Interpreter.............................................................................................................................4-13 4.4 Installing new VERBS.............................................................................................................................4-14 4.5 Installing new ADVERBS.......................................................................................................................4-16 4.6 POPSGN...................................................................................................................................................4-16 4.6.1 Function..........................................................................................................................................4-16 4.6.2 POPSDAT.HLP..........................................................................................................................4-17 4.7 INCLUDES................................................................................................................................................4-28 4.7.1 DAPL.INC....................................................................................................................................4-28 4.7.2 DBAT.INC...................................................................................................................................4-30 4.7.3 DBWT.INC...................................................................................................................................4-30 4.7.4 DCON.INC...................................................................................................................................4-31 4.7.5 DERR.INC...................................................................................................................................4-31 4.7.6 DIO.INC.......................................................................................................................................4-31 4.7.7 DPOP.INC...................................................................................................................................4-31 4.7.8 DSMS.INC....................................................................................................................................4-31 5 Catalogs 5-1 5.1 Overview ...................................................................................................................................................5-1 5.2 Public and Private catalogs....................................................................................................................5-1 5.3 File N am es................................................................................................................................................5-1 5.4 Data Catalog.............................................................................................................................................5-2 5.4.1 Catalog Directory .......................................................................................................................5-2 5.4.2 Header block................................................................................................................................5-2 5.4.3 Directory Section..........................................................................................................................5-2 5.4.4 Directory Usage ..........................................................................................................................5-3 5.4.5 Structure of The Catalog Header Record................................................................................5-3 5.4.6 Routines to Access the Data Catalog.......................................................................................5-7 5.4.7 Routines to Interpret the Catalog Header.............................................................................5-7 5.4.8 Catalog Status.............................................................................................................................5-8 5.5 Image Catalog ..........................................................................................................................................5-8 5.5.1 Overview.......................................................................................................................................5-8 5.5.2 Data Structures.............................................................................................................................5-8 iii 5.5.3 Usage notes...................................................................................................................................5-9 5.5.4 Subroutines...................................................................................................................................5-9 5.5.5 Image Catalog Commons..........................................................................................................5-9 5.6 Coordinate Systems ................................................................................................................................5-10 5.6.1 Velocity and Frequency.............................................................................................................5-10 5.6.2 Celestial Positions......................................................................................................................5-10 5.6.3 Rotations......................................................................................................................................5-13 5.7 Text of INCLUDE files............................................................................................................................5-13 5.7.1 DCAT.INC...................................................................................................................................5-13 5.7.2 DHDR.INC...................................................................................................................................5-13 5.7.3 DLOC.INC...................................................................................................................................5-14 5.7.4 DTVC.INC...................................................................................................................................5-14 5.8 Routines......................................................................................................................................................5-15 5.8.1 AXEFND......................................................................................................................................5-15 5.8.2 CATDIR......................................................................................................................................5-15 5.8.3 CATKEY......................................................................................................................................5-16 5.8.4 CATIO.........................................................................................................................................5-17 5.8.5 COORDT......................................................................................................................................5-17 5.8.6 FNDX.............................................................................................................................................5-18 5.8.7 FNDY............................................................................................................................................5-18 5.8.8 MAPCLS......................................................................................................................................5-18 5.8.9 MAPOPN......................................................................................................................................5-19 5.8.10 ROTFND......................................................................................................................................5-19 5.8.11 SETLOC......................................................................................................................................5-20 5.8.12 TVFIND ......................................................................................................................................5-20 5.8.13 UVPGET......................................................................................................................................5-20 5.8.14 XYPIX.........................................................................................................................................5-21 5.8.15 XYVAL.........................................................................................................................................5-21 5.8.16 YCINIT.........................................................................................................................................5-22 5.8.17 YCOVER......................................................................................................................................5-22 5.8.18 YCWRIT......................................................................................................................................5-22 5.8.19 YCREAD......................................................................................................................................5-23 6 Disk files 6—1 6.1 Overview ...................................................................................................................................................6-1 6.2 Types of Files............................................................................................................................................6-1 6.3 File Management......................................................................................................................................6-2 6.3.1 Creating Files................................................................................................................................6-2 6.3.2 Example Using ZCREAT..........................................................................................................6-2 6.3.3 Destruction Routines...................................................................................................................6-3 6.3.4 Expansion and Contraction of Files..........................................................................................6-3 6.4 I/O to Disk Files......................................................................................................................................6-3 6.4.1 Upper Level I/O Routines..........................................................................................................6-4 6.4.2 Logical unit numbers ................................................................................................................6-5 6.4.3 Contents of the Device Characteristics Commons .............................................................6-5 6.4.4 Image Files...................................................................................................................................6-6 6.4.5 Image File Manipulation Routines..........................................................................................6-10 6.4.6 UV Data F iles.............................................................................................................................6-11 6.4.7 UV Data Access..........................................................................................................................6-15 6.4.8 Single Dish D ata..........................................................................................................................6-19 6.4.9 Extension files .............................................................................................................................6-21 6.4.10 Text files ......................................................................................................................................6-21 6.5 Bottom Level I/O Routines...................................................................................................................6-23 6.5.1 ZMIO and ZWAIT......................................................................................................................6-23 iv 6.5.2 ZFIO .............................................................................................................................................6-24 6.6 Text of INCLUDE files.............................................................................................................................6-24 6.6.1 DDCH.INC................................................................................................................................ . 6-24 6.6.2 DSEL.INC ....................................................................................................................................6-24 6.6.3 DUVH.INC...................................................................................................................................6-27 6.7 Routines.......................................................................................................................................................6-27 . c a lc o p ..........................................................................................................! ! ! ! ! ! ! ! ! 67.1 6-27 6.7.2 CHNDAT.......................................................................................................................................6-28 6.7.3 COMOFF.......................................................................................................................................6-28 6.7.4 DGGET..........................................................................................................................................6-29 6.7.5 DGINIT..........................................................................................................................................6-29 6.7.6 EXTINI..........................................................................................................................................6-30 6.7.7 EXTIO..........................................................................................................................................6-31 6.7.8 GETVIS....................................................................................................................................... 6-32 6.7.9 GET1VS ................................................................................................................................ 6-32 6.7.10 KEYIN................................................................................................................................... 6-33 6.7.11 MAPSIZ..........................................................................................................................................6-33 6.7.12 MAPCLS............................................................................................................................. 6-33 6.7.13 MAPOPN................................................................................................................ 6-34 6.7.14 MCREAT................................................................................................................... ’ ’ 6-34 6.7.15 MDESTR................................................................................................................ 6-35 6.7.16 MDISK....................................................................................................................... 6-35 6.7.17 MINIT ................................................................................................................................’ ’ * 6-36 6.7.18 MINSK................................................................................................................................ ’ 6-37 6.7.19 M SKIP................................................................................................................... ’ ’ 6-37 6.7.20 PLNGET.............................................................................................................................’ ’ ' 6-38 6.7.21 PLNPUT.......................................................................................................................................6-39 6.7.22 SCREAT................................................................................................................................... 6-39 6.7.23 SDGET..........................................................................................................................................6-40 6.7.24 SELINI..........................................................................................................................................6-41 6.7.25 SETVIS..........................................................................................................................................6-42 6.7.26 SET1VS..........................................................................................................................................6-43 6.7.27 TABINI..........................................................................................................................................6-43 6.7.28 TABIO ..........................................................................................................................................6-45 6.7.29 UVCREA.......................................................................................................................................6-46 6.7.30 UVDISK .......................................................................................................................................6-47 6.7.31 UVGET..........................................................................................................................................$-47 6.7.32 UVINIT..........................................................................................................................................6-50 6.7.33 UVPGET.......................................................................................................................................6-51 6.7.34 ZCLOSE .......................................................................................................................................6-52 6.7.35 ZCMPRS.......................................................................................................................................6-52 6.7.36 ZCREAT.......................................................................................................................................6-53 6.7.37 ZDESTR.......................................................................................................................................6-53 6.7.38 ZEXPND.......................................................................................................................................6-53 6.7.39 ZFIO .............................................................................................................................................6-54 6.7.40 ZM IO.............................................................................................................................................6-54 6.7.41 ZOPEN..........................................................................................................................................6-54 6.7.42 ZPHFIL.........................................................................................................................................6-55 6.7.43 ZTCLOS .......................................................................................................................................6-55 6.7.44 ZTOPEN.......................................................................................................................................6-56 6.7.45 ZTREAD.......................................................................................................................................6-56 6.7.46 ZUVPAK.......................................................................................................................................6-56 6.7.47 ZUVXPN.......................................................................................................................................6-57 6.7.48 ZTXCLS .......................................................................................................................................6-57 v 6.7.49 ZTXIO .........................................................................................................................................6-57 6.7.50 ZTXOPN......................................................................................................................................6-58 6.7.51 ZUVPAK......................................................................................................................................6-58 6.7.52 ZUVXPN......................................................................................................................................6-58 6.7.53 ZWAIT.........................................................................................................................................6-59 7 High Level Utility Routines 7-1 7.1 Overview ...................................................................................................................................................7-1 7.2 File Specification......................................................................................................................................7-1 7.3 Data Calibration and Reformatting Routines...................................................................................7-1 7.4 Operations on Im ages............................................................................................................................7-1 7.5 UV Model Calculations.........................................................................................................................7-2 7.6 Image Formation......................................................................................................................................7-2 7.7 INCLUDES................................................................................................................................................7-2 7.7.1 PUVD.INC...................................................................................................................................7-2 7.7.2 DFIL.INC......................................................................................................................................7-3 7.7.3 DGDS.INC...................................................................................................................................7-3 7.7.4 DMPR.INC...................................................................................................................................7-4 7.7.5 DSEL.INC ...................................................................................................................................7-4 7.7.6 DUVH.INC...................................................................................................................................7-7 7.8 Routines......................................................................................................................................................7-7 7.8.1 APCONV......................................................................................................................................7-7 7.8.2 CALCOP......................................................................................................................................7-8 7.8.3 DSKFFT......................................................................................................................................7-9 7.8.4 GRDCOR......................................................................................................................................7-9 7.8.5 MAKMAP ...................................................................................................................................7-10 7.8.6 UVGET.........................................................................................................................................7-15 7.8.7 UVMDIV......................................................................................................................................7-17 7.8.8 UVMSUB......................................................................................................................................7-18 8 WaWa (“Easy”) I/O 8-1 8.1 Overview ...................................................................................................................................................8-1 8.2 Salient Features of the WaWa I/O package ......................................................................................8-1 8.3 Namestrings................................................................................................................................................8-1 8.4 Subroutines................................................................................................................................................8-2 8.5 Things WaWa Can’t Do Well or At All................................................................................................8-3 8.5.1 Non-map files................................................................................................................................8-3 8.5.2 UV data files................................................................................................................................8-3 8.5.3 Plotting.........................................................................................................................................8-3 8.5.4 History..........................................................................................................................................8-3 8.5.5 More than 5 I/O Streams at a Tim e......................................................................................8-3 8.5.6 I/O to Tapes................................................................................................................................8-3 8.6 Additional goodies and “helpful” hints................................................................................................8-4 8.6.1 Use of LUNs................................................................................................................................8-4 8.6.2 WaWa commons.........................................................................................................................8-4 8.6.3 Error return codes......................................................................................................................8-6 8.7 INCLUDES................................................................................................................................................8-6 8.7.1 DBUF.INC...................................................................................................................................8-6 8.7.2 DCAT.INC...................................................................................................................................8-7 8.7.3 DFIL.INC......................................................................................................................................8-7 8.7.4 DITB.INC ...................................................................................................................................8-7 8.8 Detailed Descriptions of the Subroutines.............................................................................................8-7 8.8.1 A2WAWA......................................................................................................................................8-7 8.8.2 CLENUP......................................................................................................................................8-8 vi 8.8.3 FILCLS..........................................................................................................................................8-8 8.8.4 FILCR.............................................................................................................................................8-8 8.8.5 FILDES..........................................................................................................................................8-9 8.8.6 FILIO.............................................................................................................................................8-9 8.8.7 FILNUM.......................................................................................................................................8-9 8.8.8 FILOPN..........................................................................................................................................8-10 8.8.9 GETHDR.......................................................................................................................................8-10 8.8.10 HDRINF .......................................................................................................................................8-10 8.8.11 H2WAWA.......................................................................................................................................8-11 8.8.12 IOSET.............................................................................................................................................8-11 8.8.13 MAPCR..........................................................................................................................................8-11 8.8.14 MAPIO..........................................................................................................................................8-12 8.8.15 MAPMAX ...................................................................................................................................8-12 8.8.16 MAPWIN.......................................................................................................................................8-12 8.8.17 MAPXY..........................................................................................................................................8-13 8.8.18 OPENCF.......................................................................................................................................8-13 8.8.19 SAVHDR.......................................................................................................................................8-13 8.8.20 TSKBEG.......................................................................................................................................8-14 8.8.21 TSKEND.......................................................................................................................................8-14 8.8.22 UNSCR..........................................................................................................................................8-14 8.8.23 WAWA2A.......................................................................................................................................8-14 A AIPS Directory Structure and Software Management A -l A.l Introduction................................................................................................................................................A-l A.2 Directory Structure...................................................................................................................................A-l A.2.1 Design Guidelines .......................................................................................................................A-l A.2.2 Directory Structure ....................................................................................................................A-2 A.2.3 Mnemonics - AREAS.DAT.......................................................................................................A-8 A.3 File Names For D ata................................................................................................................................A-14 A.4 VMS Details .............................................................................................................................................A-15 A.4.1 Object libraries.............................................................................................................................A-15 A.5 A-Tutorial for Programmers Using VMS.............................................................................................A-16 A.5.1 Initialization and Startup Procedures ....................................................................................A-16 A.5.2 Compiling and Linking................................................................................................................A-16 A.5.3 Miscellaneous routines................................................................................................................A-l8 A.5.4 Compiling and Linking: An Example.......................................................................................A-18 A.5.5 Debugging under VMS................................................................................................................A-20 A.5.6 Check out system..........................................................................................................................A-20 A.6 Unix Details................................................................................................................................................A-21 A.6.1 Mnemonics...................................................................................................................................A-21 A.6.2 Object Libraries..........................................................................................................................A-21 A.7 A Tutorial for Programmers Using Unix.............................................................................................A-27 A.7.1 Initialization And Startup Procedures....................................................................................A-27 A.7.2 Miscellaneous Routines .............................................................................................................A-35 A.7.3 Compiling and linking, an example..........................................................................................A-35 A.7.4 Non-standard INCLUDE files....................................................................................................A-39 A.7.5 Running Tasks from Private Directories................................................................................A-39 A.7.6 Debugging under Unix................................................................................................................A-39 A.7.7 Check out system .......................................................................................................................A-39 vii B Shopping lists B -l B.l Introduction...............................................................................................................................................B-l B.1.1 AP-APPL......................................................................................................................................B-3 B.l.2 AP-FFT.........................................................................................................................................B-5 B.1.3 AP-UTIL......................................................................................................................................B-5 B.l.4 BATCH.........................................................................................................................................B-5 B.l.5 BINARY ......................................................................................................................................B-6 B.1.6 CALIBRATION.........................................................................................................................B-6 B.l.7 CATALOG...................................................................................................................................B-8 B.l.8 CHARACTER............................................................................................................................B-8 B.1.9 COORDINATES.........................................................................................................................B-9 B.l. 10 EXT-APPL...................................................................................................................................B-9 B.l.11 EXT-UTIL...................................................................................................................................B-10 B.l.12 FITS...............................................................................................................................................B-ll B.l.13 GRAPHICS...................................................................................................................................B-12 B.l.14 HEADER......................................................................................................................................B-13 B.l.15 HISTORY......................................................................................................................................B-13 B.l.16 IO-APPL......................................................................................................................................B-14 B.l. 17 IO-BASIC......................................................................................................................................B-14 B.l.18 IO-TV............................................................................................................................................B-15 B.l.19 IO-UTIL ......................................................................................................................................B-15 B.l.20 IO-WAWA ...................................................................................................................................b-16 B.1.21 MAP ............................................................................................................................................b-17 B.1.22 MAP-UTIL...................................................................................................................................B-18 B.l.23 MATH............................................................................................................................................B-18 B.l.24 MESSAGES ...............................................................................................................................B-20 B.1.25 MODELING................................................................................................................................B-20 B.1.26 PARSING......................................................................................................................................B-20 B.l.27 PLOT-APPL...............................................................................................................................B-21 B.l.28 PLOT-UTIL...............................................................................................................................B-21 B.1.29 POPS-APPL................................................................................................................................B-22 B.1.30 POPS-LANG................................................................................................................................B-23 B.l.31 POPS-UTIL ................................................................................................................................B-23 B.l.32 PRINTER ...................................................................................................................................B-23 B.l.33 SDISH............................................................................................................................................B-24 B.l.34 SERVICE......................................................................................................................................B-24 B.l.35 SLICE............................................................................................................................................B-24 B.1.36 SORT............................................................................................................................................B-25 B.l.37 SPECTRAL ................................................................................................................................B-25 B.l.38 SYSTEM......................................................................................................................................B-25 B.1.39 TAPE............................................................................................................................................B-26 B.l.40 TERMINAL ................................................................................................................................B-27 B.l.41 TEXT............................................................................................................................................B-27 B.l.42 TV ...................................................................................................................................................B-27 B.1.43 TV-APPL......................................................................................................................................B-27 B.1.44 TV-BASIC...................................................................................................................................B-28 B.l.45 TV-IO............................................................................................................................................B-28 B.l.46 TV-UTIL......................................................................................................................................B-29 B.l.47 UTILITY......................................................................................................................................B-30 B.1.48 UV...................................................................................................................................................B-31 B.1.49 UV-UTIL......................................................................................................................................B-33 B.l.50 VLA...............................................................................................................................................B-33 B.1.51 Y 0...................................................................................................................................................B-33 B.l.52 Y 1...................................................................................................................................................B-33 viii