The Programmer's Guide to TRSDOS Version 6 - Tim Mann's Home ...

More documents

Recommendations

Info

8.11 SYSTEM OVERLAY CONTENTS A system as complex and flexible as LDOS would occupy considerable memory space to be able to provide all of its features. The DOS, however, makes extensive use of overlay segments in order to minimize the amount of memory reserved for system use. The compromize in using an overlay driven system, is that while a user's application is in progress, certain disk file activities requested of the system may require the operating system to load different overlays to satisfy the request. This could cause the system to run slightly slower than a less sophisticated system which has more of its file access routines always resident in memory. The system provides a procedure to permanently place specified overlays into memory to enhance the overall speed of operation (see the SYSTEM command). The following will describe the functions performed by each system overlay. Numbers in angle brackets represent the system SVC entry. 8.11.1 SYS0/SYS This is not an overlay. It contains the resident part of the operating system (SYSRES ). 8.11.2 SYS1/SYS This overlay contains the command interpreter. This processes @CMNDI and @CMNDR . It contains the routines for processing the @FEXT SVC , the routines for processing the @FSPEC SVC , and the routines for processing the @PARAM SVC . It also contains the @EXIT processor . 8.11.3 SYS2/SYS This overlay is used for opening or initializing disk files and logical devices. It contains the functions for @RENAM and @GTDCB . It also contains the @CKDRV routines , and routines for hashing file specifications and passwords . 8.11.4 SYS3/SYS This overlay contains all of the system routines needed to close files and devices . It also contains the routines needed to service the @FNAME SVC . 8.11.5 SYS4/SYS This system overlay contains the system error dictionary and @ERROR SVC processing routines. 8.11.6 SYS5/SYS This overlay contains the system debugger. 8.11.7 SYS6/SYS This overlay contains all of the algorithms and routines necessary to service the LIBrary commands identified as "Library A" by the LIB command. The following list identifies the commands and their ISAM entry number. 21 DIR 63 RESET 53 RENAME 61 DEVICE 65 SET 1E MEMORY 32 COPY 66 FILTER 91 DO 31 APPEND 41 LIST 81 LOAD 64 ROUTE 18 REMOVE 82 RUN 62 LINK 19 LIB 8.11.8 SYS7/SYS This overlay contains all of the algorithms and routines necessary to service the LIBrary commands identified as "Library B" by the LIB command. The following list identifies the commands and their ISAM entry number. 8-27
14 DEBUG 72 PURGE 1B VERIFY 71 DUMP 15 DATE 13 CREATE 16 TIME 11 AUTO 22 FREE 33 BUILD 51 ATTRIB 8.11.9 SYS8/SYS This overlay contains all of the algorithms and routines necessary to service the LIBrary commands identified as "Library C" by the LIB command. The following list identifies the commands and their ISAM entry number. A1 SYSTEM 1C SYSGEN B1 FORMS B2 SETCOM B3 SETKI A2 SPOOL 8.11.10 SYS9/SYS This overlay contains the routines necessary to service the EXTended debugging commands available after a DEBUG (EXT) is performed. 8.11.11 SYS10/SYS This system overlay contains the procedures necessary to service the request to REMOVE a file . 8.11.12 SYS11/SYS This overlay contains all of the procedures necessary to perform the Job Control Language execution phase. These are the initial entry for setup and initialization , the revised @EXIT processor , keyboard request processing , and //INPUT keyboard processing . 8.11.13 SYS12/SYS This overlay contains the routines to service the @RAMDIR and the @DODIR SuperVisor Calls. It also includes the routines to service the @GTMOD function . 8.11.14 SYS13/SYS Effective with release 6.2.0, SYS13 can be used by an application environment for an Extended Command Interpreter (ECI). This ECI gains control from SYS1 on any of the following SVCs: @ABORT, @CMNDI, @CMNDR, and @EXIT. The programmer develops the ECI and copies it to the application system disk SYS13/SYS module via the command: COPY usereci SYS13/SYS.LSIDOS:d (C=N) The programmer then sets the EFLAG$ and invokes SYSGEN to save the EFLAG$ configuration. Upon entry to the ECI, the registers will be set as for any other program execution (see page 6-100), with the exception of register A. Bits 4-6 of the accumulator will contain an image of the respective EFLAG$ bits. The ECI programmer may use different EFLAG$ assignments in a multiple module application environment to invoke the ECI with different entry points. 8-28
Page 1 and 2:
MISOSYS, INC. The Programmer's Guid
Page 3 and 4:
1. Introduction Many thousands of u
Page 5 and 6:
language (i.e. BASIC, C, PASCAL, ..
Page 7 and 8:
NAME START END DESCRIPTION LOWCORE
Page 9 and 10:
ackup utility provides exceptional
Page 11 and 12:
3. Device Input/Output Interfacing
Page 13 and 14:
3.2.2 VECTOR Field - This field in
Page 15 and 16:
FILTER *PR USING *S0 the operating
Page 17 and 18:
===================================
Page 19 and 20:
===================================
Page 21 and 22:
ENTRY JR BEGIN ;Branch around linka
Page 23 and 24:
DATA1 EQU $-DATA$ DB 0 ;Data storag
Page 25 and 26:
Offset Contents +0 Contains the las
Page 27 and 28:
image of the serial port UART statu
Page 29 and 30:
called TRACKs. Each track is then d
Page 31 and 32:
The DCT contains the information re
Page 33 and 34:
accessed a single-sided diskette, t
Page 35 and 36:
containing the disk's directory. Th
Page 37 and 38:
Command Purpose RESTORE Recalibrate
Page 39 and 40:
available from Logical Systems, Inc
Page 41 and 42:
exceeds this capacity, then it must
Page 43 and 44:
is two physical cylinders. Although
Page 45 and 46:
5. The DOS Directory Structure 5.1
Page 47 and 48:
===================================
Page 49 and 50:
5.2.8 PACK NAME - This field conta
Page 51 and 52:
The position of a file's hash code
Page 53 and 54:
5.4 THE DIRECTORY RECORD STRUCTURE
Page 55 and 56:
Bit 3 Specifies the visibility; if
Page 57 and 58:
the first granule in use is the sec
Page 59 and 60:
travels the turnpike. In this manne
Page 61 and 62:
The @FSPEC SVC will transfer the fi
Page 63 and 64:
A high level language permits you t
Page 65 and 66:
does exist, @RENAME should return e
Page 67 and 68:
Next, it would be very useful if th
Page 69 and 70:
LD HL,FCBX+9 ;Point to the LRL fiel
Page 71 and 72:
operating system for such a purpose
Page 73 and 74:
position where the last character i
Page 75 and 76:
ecord. If a file has more than four
Page 77 and 78:
DE Contains a pointer to the File C
Page 79 and 80:
@RENAM SVC-56 Rename a file on disk
Page 81 and 82:
@FNAME SVC-80 Obtain filespec given
Page 83 and 84:
@WRSEC SVC-53 Write a disk sector @
Page 85 and 86:
7.6 SUPERVISOR CALL DETAILS 7.6.1 @
Page 87 and 88:
Note: @EXIT in SYS1 automatically r
Page 89 and 90:
7.6.10 @CLOSE SVC-60 This SVC will
Page 91 and 92:
7.6.18 @DCSTAT SVC-40 This SVC pass
Page 93 and 94:
Directory to Buffer Entry: B 1; Fun
Page 95 and 96: 7.6.31 @FLAGS$ SVC-101 This SVC wil
Page 97 and 98: NFLAG$ This "network" flag is used
Page 99 and 100: 7.6.32 @FNAME SVC-80 This SVC will
Page 101 and 102: 7.6.40 @HEX8 SVC-98 This SVC will c
Page 103 and 104: 7.6.48 @KLTSK SVC-32 This SVC will
Page 105 and 106: 7.6.57 @OPEN SVC-59 This SVC will o
Page 107 and 108: Registers Affected: AF, BC. Entry:
Page 109 and 110: 0-14 FILENAME/EXT:D - left justifie
Page 111 and 112: 7.6.71 @REMOV SVC-57 This SVC will
Page 113 and 114: Entry: DE A pointer to the FCB cont
Page 115 and 116: Exit: A Error return code, if any.
Page 117 and 118: CURSOR CHARACTER Registers Affected
Page 119 and 120: Exit: A Will contain the error code
Page 121 and 122: esident routine into its execution
Page 123 and 124: CKPAWS LD A,@FLAGS$ ;Get Flags poin
Page 125 and 126: ===================================
Page 127 and 128: The TYPE=0A indicates that it is th
Page 129 and 130: Error 08: Device not available A re
Page 131 and 132: Error 28: End of file encountered T
Page 133 and 134: 8.5 HEADER PROTOCOL OF MEMORY MODUL
Page 135 and 136: This is obviously an extremely usel
Page 137 and 138: LD (IX+2),15 JR TASKA By firmly und
Page 139 and 140: 8.7.3 Details of Low Memory Page 2
Page 141 and 142: actual bank switching. As previousl
Page 143 and 144: set. Thus, the Z-flag will be indic
Page 145: 8.10 SYSTEM DISK BOOT TRACK The ope
Page 149 and 150: 8.13 USING @PARAM The @PARAM SuperV
Page 151 and 152: DW LPARM+1 DB 'FEED ' ;Line feed pa
Page 153 and 154: ;*=*=* PPARM LD BC,0 ;Zero because
Page 155 and 156: 8.14 TRAP Filter Illustrated ;TRAP/
Page 157 and 158: 8.15 SLASH0 Filter Illustrated ;SLA
Page 159 and 160: 8.16 DMP-500 BOLDFACE Filter Illust
Page 161 and 162: NOMEM$ DB 'High memory is not avail
Page 163 and 164: @ @ABORT..........7-2, 7-4, 7-8, 7-
show all

The Programmer's Guide to TRSDOS Version 6 - Tim Mann's Home ...

Create successful ePaper yourself

Delete template?

Save as template?