HP Logical Interchange Format For Mass Storage Devices The basic unit of storage is the record or sector. The HP82161 tape drive has 2 tracks with 256 records per track, 256 bytes per record. The SB10160 disk drive uses 40 tracks with 9 records per track, 512 bytes per record (per side). Record 2 is always the start of the directory. HEX R R R VOLLBL holds ASCII data. Not used by HP41 or HP75. ADR 0 1 2 R0 08-0B: start of directory - always 00 00 00 02. R0 10-13 Directory length in records. Max 8 files per record, -1. 00 80 A F R1 All zeroes. Future use. 01 00 L I R2 00-09 File name. ASCII data. Default fill: HEX 20 (space). 02 V L L WARNING: The HP75 uses the first HEX 20 character as end of filename 03 O E Two part names and names starting with a space will give 04 L Z N problems. Such names should not be used with HP41 interchange files. 05 L E A R2 0A-0B : File type. 06 B R M 00 00 : Purged (Reserves space). 07 L O E 00 01 : ASCII/TEXT -- no header: HP41 AS, HP75 I (LIF), HP71 TEXT 08 00 E FF FF : Unused or end of directory. 09 00 S E0 70 : HP41 ROM files (ERAMCO) or Extended Memory files (PANAME) 0A 00 . FILE E0 40 : HP41 WALL. E0 50 : HP41 KEYS. 0B 02 . TYPE E0 52 : HP75 text and key assignment files -- 53 HP75 Appointments 0C 10 . S R E0 58 : HP75 Mass Storage Data Base files. WARNING: FLEN=FFFFsize 0D 00 . T E E0 60 : HP41 Status. 0E 00 . R C E0 80 : HP41 Programs. 0F 00 . T # E0 88 : HP75 (P)BASIC files -- 89:LEX 10 D L . F E0 8A : Visicalc Worksheets -- 8B : PMS ROM files 11 I E . L E0 D0 : HP41 DATA, HP71 SDATA -- D1 : HP71 Secure Text 12 R N . E R2 10-13 : Start Address of file - 0E=track, 0F=record. 13 G . N R2 10-13 : # of records allocated to file, Hex. 14 00 . yy R2 14-19 : Time of creation. Not used by HP41. 15 01 . mm R2 1A-1B : Volume flag/Number. Usually Hex 8001. 16 00 . dd R2 1C-1F : Implementation dependent. HP75 Password. HP71 file length. 17 00 . hh 1C,1D : HP41 program length in bytes, or file in registers. HP71 SDATA = HP41 DATA. 18 # 00 . mm 1C-1D : Number of records - HP71 DATA. 19 T 00 . ss 1E-1F : Defined record length - HP71 DATA. 1A R 00 . ? HP41 1E : Gives 01=private, 02=auto, 03=auto&private, 08=secured 1B K 02 . ?? 09=private&secured 0A=auto&secured 0B=auto&private&secured. 1C # 00 . F 1F : HP41= HEX 20 or FF, HP71= HEX 00 1D S 00 . L The next directory entry follows. 1E R 00 . st The last 32 bytes in the directory (system use)- all FF. 1F F 01 . 20 20 # 00 . * *=First character of entry#2 filename. 21 R 00 . . Record 0, HP71 or HP75: Other HP71 file types: Add 1 to byte 0B if secured 22 E 01 . . R0 0C-0D: System 3000 Type Byte 0A 0B : Add 2 to byte 0B if private 23 C 00 . . R0 14-15: Version DATA E0 F0 Only BIN & BASIC may be private 24 D yy . . R0 18-1B: Tracks per surface BIN E2 04 25 A mm . . R0 1C-1F: # of surfaces LEX E2 08 26 T dd . . R0 20-23: # records per track KEY E2 0C 27 E hh . . R0 24-29: Date & time initialized BASIC E2 14 28 + mm . . R0 2A-FF: Extensions & Maintenance FORTH E2 18 29 ss . . (Future use) ROM E2 1C Rev. 7 11/1/85 by Michael Markov <3>(6749)