Epson TF-20 Reference Manual

Hx-20 disk basic
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Summary of Contents for Epson TF-20

  • Page 2 FOREWORD This manual covers the specifications and use of the hardware and software of the TF-20 Flexible Disk Unit designed exclusively for use with the HX-20 portable computer. To get the fullest use from your TF-20. please read this manual carefully before attempting to operate the unit.
  • Page 3: Table Of Contents

    TABLE OF CONTENTS FOREWARD......................i 1. INTRODUCTION..................1-1 1.1 Sequential Files and Random Access Files ..........1-2 1.2 Flexible Disks....................1-2 2. GETTING STARTED..................2-1 2.1 Unpacking....................2-1 2.2 Names of Parts................... 2-2 2.3 Hardware Configuration ................2-2 2.4 Operation....................2-4 3.
  • Page 4: Introduction

    In Disk BASIC (the name of the version of BASIC used to operate the RESET........4-25 TF-20), the fixed length of records is 128 bytes. To fix the length of the RUN........4-26 variables used in a random access file, the FIELD statement is necessary.
  • Page 5: Flexible Disks

    Because the disks the drive. The flexible disks used in the TF-20 are double-sided disks which record data magnetically, disks should never be used or stored near magnets or in a strong magnetic field, such as that produced by a measure 5 1/4"...
  • Page 6: Getting Started

    2. GETTING STARTED 2.1 Unpacking When unpacking the TF-20, make sure that all of the following items are included. ® Fig. 2.1 Packing List All packing materials should be saved for reshipment of the TF-20.
  • Page 7: Names Of Parts

    TF-20 5-pin DIN second TF-20. Change the setting of DIP switch 4 to OFF. DIP switch 4 is located on the rear, lefthand side of the PC board (in front of the 5-pin interface connector). The location of DIP switch 4 is shown in the Fig.
  • Page 8: Operation

    Before starting up, DIP switch 4 of the HX-20 must be turned ON If it is not turned ON, you will not be able to boot Disk BASIC even if the TF-20 units are correctly connected to the HX-20.
  • Page 9: Disks

    2) Check the orientation of the disk (write protect notch up, identification label to the right) before setting the disk in the drive. (If the orientation of the disk is not correct, the TF-20 will not operate.) 3) Always remove disks from the drive after checking to make sure that the drive select indicator is extinguished.
  • Page 10: System And Non-System Disks

    Of this total, tracks 0 through 3 (sides 0 and 1) are used as the system area (for the operating system of the TF-20), the first 8 sectors of track 4 (side 0) 3.3 FORMAT, SYSGEN and COPY are used as the directory area and track 39 is reserved.
  • Page 11: Cautions When Replacing Disks

    A can be copied to the disk in drive B (or similarly, from C to D if two TF-20 disk units are being used). The copy utility can also be used to copy single files as selected by the user. See 4.6 Copy Utility, for details.
  • Page 12: Care And Handling Of Flexible Disks

    Do not use an eraser to erase the identification labels This creates 3.5 Care and Handling of Flexible Disks gummy residue that can damage the disks As mentioned earlier, the nature of flexible disks requires that they be handled with a certain amount of care. Please read carefully and observe the below-listed precautions to get the maximum use and service life from your flexible disks 1 Never touch the magnetic recording...
  • Page 13: Cautions On Placement Of Disk Drive

    Avoid use of the disk drive in a very humid atmosphere or where it wi l l be exposed to oily or metalli The TF-20 is composed of precision parts Place it where it will be protected from shock and excessive vibration Place the disk drive as shown in Fig 3 2 Do not place it on its si d e.
  • Page 14: Disk Basic

    (In an emergency, When the TF-20 is connected to the HX-20, starting up BASIC will cause flexible disks can be used for this purpose, although there is a strong...
  • Page 15: Disk Basic Features

    After making all of the above checks, carefully set the system disk in drive (2) Protect SAVE A When you do so, the indicator lamp on the TF-20 will turn on and off and When the P option is specified in a SAVE statement, the program saved...
  • Page 16: Disk Basic Syntax

    (a) A non-system disk has been set in drive A (a) Device name (b) The HX-20 and the TF-20 are not properly connected In Disk BASIC, in addition to the device names that could be used in ROM (c) There is a malfunction in the TF-20 BASIC, you can now use device names "A ", "B ", "C."...
  • Page 17: Commands And Statements

    DSKO 4.4 Commands and Statements To write data directly to a disk The commands and statements used in Disk BASIC are as follows. DSKO$ <drive name>, <track No.>, <sector No.>, <string expression> DSKO$ "A:", 1, 5, A$ This command is a disk output command to write the To close file(s) contents of <strmg expression>...
  • Page 18 FIELD Physical Sector <sector No > SideO 1 First half To define the field of the random file buffer Second half 2 First half FIELD [#] <file No.>, <field length> AS <string Second half variablo [,<field |ength> AS <stnng variable>...] FIELD #1, 20 AS A$, 35 AS B$ 16 First half Before data can be written into (PUT) or read from (GET) the...
  • Page 19 INPUT# KILL To read a single item of data from a sequential file and assign To delete a file from the disk it to a variable KILL <file descriptor> INPUT# <file No.>, <variable list> KILL "B:TEST.BAS" INPUT# 1, A, B$ <file descriptor>...
  • Page 20 LIST LOADM To output a program list to the specified file. To load a machine language program file into the memory- LIST <file descriptors [,[<line number>] LOADM [<file descriptor>][,[offset value][,R]] [-[<line number>]]] LOADM "B:ABC" LIST "B:TEST.ASC", 3 0 - 8 0 The file to be loaded should be a machine language program The function of LIST when followed by a file descriptor is the file created by the monitor function or the SAVEM command.
  • Page 21: Filnum

    When the device specified in <file descriptor> is not the FILNUM specifies the number of files that can be opened TF-20, (i.e., "CAS0:", "CAS1:" or "PAC0:"), the FILES simultaneously during the execution of a BASIC program. statement displays the names of the files in the specified...
  • Page 22: Frmat

    "N" if you wish to cancel "0V" or "FC" error will occur Also, if a <record No > which When using a non-EPSON disk for the first time, formatting exceeds the size of the current file, or is in a block whose...
  • Page 23: Merge

    RSET <string variable> = <string> MERGE "A:PROG3.ASC" LSET A$ = "EPSON" RSET B$ = "TF-20" MERGE command merges the program file specified by <file descriptor> into the program in the memory area To store data in the random file buffer, RSET or LSET must...
  • Page 24: Open

    OPEN NAME To open a file for I/O. To change the name of a disk file. OPEN <mode>, [#] <file No.>, <file descriptor> NAME <current file descriptor> AS <new file descriptor OPEN "R", # 1, "B:TEST.DAT" NAME "TEST" AS "TEST 1" This statement opens the file specified by <file descriptor>...
  • Page 25 PRINT# USING PRINT# To output data to a sequential file To write strings and numerics into a sequential file using a specified format PRINT# <file No.> [,<expression>] PRINT#<file number>, USING<"format string">; PRINT# 1, A$ [<expression>[ ; <expression>. . .]] <file No > is the number specified when the file was opened for sequential output.
  • Page 26: Put

    If it is not, a "Bad record number", "0V" or "FC" error will TF-20 is connected.) If "A:" or "B:" are specified, the first TF-20 is reset and the occur. The file against which the PUT statement is executed must disks set in either drive can be replaced.
  • Page 27: Run

    SAVE Sample Programs (Direct mode) CLOSE (replace the disk) RESET (Program mode) SAVE "B:PRG",A 100 CLOSE 110 PRINT "REPLACE DISK If the A option is specified, BASIC will save the program in AND PRESS ANY KEY" ASCII format Otherwise, the program will be saved in 110 H$=INPUT$(I) compressed binary format ASCII format requires more time and memory but is required when inputting files with the...
  • Page 28: Savem

    WHILE . . . WEND SAVEM To conditionally execute the statements in a loop. To save the memory contents on a specified file. WHILE <expression> SAVEM <file descriptors <top address>, <bottom address>, <execution starting address> [<loop statements>] SAVEM "B:ABC", &H0B00, &H0C00, &H0B00 WEND SAVEM saves a machine language program or memory WHILE l<5...
  • Page 29: Disk Basic Functions

    SYSGEN 4.5 Disk BASIC Functions To create a new system disk. CVI, CVS, CVD SYSGEN SYSGEN To convert string data back to numeric data. Before executing the SYSGEN statement, first place the <2-byte string> source system disk in drive A and the disk which you wish to CVS <4-byte string>...
  • Page 30: Dski

    DSKF To return the end-of-file code. To return the free area remaining on the disk. EOF (<file number>) DSKF (<drive name>) IF EOF (1) THEN CLOSE #1 ELSE GOTO 100 PRINT DSKF ("A:") The file specified by <file number> must have been opened DSKF returns the amount of free area in the disk set in the for the input mode.
  • Page 31: Loc

    To return the current record No. LOC (<file No.>) PRINT LOC (1) If the file specified in <file No.> was opened in the R mode, the record No. of the record used in the last GET or PUT statement is returned If the file was opened in the I mode, the number of logical sectors (128-byte units) read so far is returned.
  • Page 32: Copy Utility

    (b) Copying disks 4.6 COPY Utility © Select "1" from the screen displayed in Screen 1 above @ The following will be displayed asking you to make your selection of To protect your important programs and files against loss due to disk drives misoperation or accident, it is always a good idea to make backup copies of such disks This is a utility program, supplied on the system disk, which...
  • Page 33: Error Processing

    (5) DU This error occurs when an attempt is made to access a drive which does not contain a disk. The TF-20 containing that drive will continue to output this error until a disk is inserted in the drive. NOTE: There may be instances when a READ error occurs during execution of a PUT statement.
  • Page 34 5. HARDWARE The TF-20 is an intelligent flexible disk unit incorporating a CPU, a 64K-byte memory and l/0's. Therefore, it lightens the workload for file management of the CPU in the host computer and reduces the amount of memory space in the host computer to be occupied by the operating system (OS).
  • Page 35: Interface Signals

    "HIGH" level of this signal enables serial output Ground GNDS — 5.3 Interface Level RS-232C serial interface: Logic 1 (-3 to -27V) Logic 0 (+3 to +27V) NOTE: The interface on the rear panel of the TF-20 is not used.
  • Page 36 APPENDIX A ERROR CODES For Disk BASIC, the following error codes have been added. Error code Error message Directory full The disk is full and new files cannot be created. Each file uses a directory for every 32K bytes so this error can also result from file expansion.
  • Page 37 APPENDIX C POWER REQUIREMENTS APPENDIX B DISKDRIVE AND OUTLINE DIMENSIONS ENVIRONMENTAL CONDITIONS Power Requirements Power Frequency : 49.5 to 60.5 Hz Temperature Power Consumption : 40W 5 to 28°C Operating state -30 to 65°C Non-operating state Outline Dimensions and Weight Outline Dimensions : 120(W) mmx350(D)mmx165(H)mm Humidity...
  • Page 38 Storage 4 to 53°C Transport -50to53°C Humidity Operation 20 to 80% RH (Max. wet bulb temperature: 29°C) EPSON OVERSEAS MARKETING LOCATIONS Storage 8 to 80% RH EPSON UK LTD EPSON AMERICA, INC. Dorland House 3415 Kashiwa Street Transport 8 to 90% RH...

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