forked from microsoft/GW-BASIC
/
MSDOSU
108 lines (94 loc) · 3.27 KB
/
MSDOSU
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
; [ This translation created 12-Jan-83 by Version 4.3 ]
SUBTTL MSDOSU - MS-DOS Constants and Data-Structure Definitions
COMMENT *
--------- --- ---- -- ---------
COPYRIGHT (C) 1982 BY MICROSOFT
--------- --- ---- -- ---------
Programmer: Tom Corbett, Microsoft Inc.
*
CALLOS MACRO FUNC
IFNB <FUNC>
MOV AH,LOW OFFSET FUNC
ENDIF
INT 33D ;MSDOS system call
ENDM
ROFFST MACRO NAME,SIZE ;define record macro
NAME=_OFFST
_OFFST=_OFFST+SIZE
ENDM
; MSDOS System Call codes
;
C_PRTO=5D ;Printer output
C_DCIO=6D ;Direct console I/O
C_REST=13D ;INITIALIZE BDOS
C_SDRV=14D ;SET CURRENTLY SELECTED DRIVE
C_OPEN=15D
C_CLOS=16D
C_SEAR=17D ;SEARCH FOR FILE
C_DELE=19D
C_READ=20D
C_MAKE=22D
C_RENA=23D
C_GDRV=25D ;GET CURRENTLY SELECTED DRIVE
C_BUFF=26D ;SET DMA ADDRESS
C_RNDR=33D ;Random read
C_RNDW=34D ;Random write
C_RBR=39D ;Random Block Read
C_PARS=41D ;Parse Filename
FNAML=11D ;number of bytes in Filename with extension
DATPSC=128D ;bytes per sector
FCBSIZ=38D ;File Control Block size
;MS-DOS FILE-DATA-BLOCK Record Definition
;
_OFFST=0 ;initialize count
ROFFST F_NUL1,1 ;not used by basic interpreter
ROFFST F_NUM,1 ;file number 0..255
ROFFST F_NUL2,2 ;not used by basic interpreter
ROFFST F_NEXT,2 ;thread for linked list, [MEMSIZ]=end
ROFFST F_MODE,1 ;file mode:
MD_SQI=1D ;sequential input
MD_SQO=2D ;sequential output
MD_RND=4D ;random
MD_APP=8D ;append
ROFFST F_FCB,FCBSIZ ;File Control Block: used to communicate with OS
ROFFST F_CLOC,2 ;for seq files: num sectors read/written (LOCOFS)
;for rnd files: last record number + 1
ROFFST F_ORCT,1 ;"Original Byte Count" (ORNOFS)
;for seq input: #bytes in sector when read
;for seq output: #bytes in output sector
;for random files: bytes per sector
ROFFST F_BREM,1 ;number of bytes till end-of-buffer (NMLOFS)
ROFFST F_CODE,1 ;file encoding:
FC_ASC=0 ;Ascii SAVE, Data files
FC_BIN=1 ;binary file (BSAVE, binary SAVE)
ROFFST F_BAKC,1 ;holds next sequential input when F.FLBS.FL.BKC is true
ROFFST F_NUL3,1 ;not used by basic interpreter
ROFFST F_DEV,1 ;Device number (FL.DSK)
ROFFST F_WID,1 ;File width
ROFFST F_NUL4,1 ;not used by basic interpreter
ROFFST F_FLGS,1 ;flags
FL_BKC=200O ;when true, F.BAKC contains next sequential input
ROFFST F_POS,1 ;Current column position (FL.OPS)
ROFFST FDBSIZ,0 ;size of device independent part of FDB
;device dependant FDB entries start here
ROFFST DATOFS,DATPSC ;Operating System interface buffer
ROFFST FD_SIZ,2 ;variable record length for random files
ROFFST FD_PHY,2 ;current physical record number
ROFFST FD_LOG,2 ;current logical record number
ROFFST F_NUL5,1 ;Future use
ROFFST FD_OPS,2 ;current output position for sequential I/O
ROFFST FD_DAT,0 ;field buffer of random file
; OFFSETS INTO MSDOS FCB
;
FCB_DV=F_FCB+0D ;DRIVE (0=default, 1=A:, 2=B:, ...)
FCB_FN=F_FCB+1D ;FILE NAME
FCB_FT=F_FCB+9D ;EXTENSION
FCB_EX=F_FCB+12D ;FILE EXTENT (identifies block of 128 logical records)
FCB_RC=F_FCB+14D ;RECORD SIZE
FCB_FS=F_FCB+16D ;FILE SIZE IN BYTES
FCB_DT=F_FCB+20D ;Date of last write to file
FCB_DT=F_FCB+22D ;Time of last write to file
FCB_NR=F_FCB+32D ;NEXT RECORD NUMBER
FCB_RN=F_FCB+33D ;CP/M 2.x Random Record Number
PAGE