TRS-DOS
Encyclopedia
TRS-DOS was the operating system
for the Tandy TRS-80 line of 8-bit Zilog Z80
microcomputers that were sold through Radio Shack
through the late 1970s and early 1980s. Tandy's manuals recommended that it be pronounced triss-doss. TRS-DOS should not be confused with Tandy DOS a version of MS-DOS
licensed from Microsoft
for Tandy's x86 line of personal computer
s (PCs).
TRS-DOS was primarily a way of extending the MBASIC (BASIC
in ROM
) with additional I/O
(input/output) commands that worked with disk files rather than the cassette tapes that were used by most other TRS-80 systems.
TRS-DOS supported up to four floppy (mini-diskette) drives which used 5" (five and one quarter inch) diskettes with a capacity of 89K (kilobyte
s) each (later 160K). The drives were numbered 0 through 3 and the system diskettes (which contained the TRS-DOS code and utilities) had to be in drive 0.
Although MS-DOS owes its heritage most closely to CP/M
and thence to TOPS-10
, many of the file manipulation commands are very similar to those of TRS-DOS. By comparison the CP/M
command for copying files was called pip (both a pun on the Pip printers, a chain of copy centers in that era, and an acronym standing for "Peripheral Interchange Program").
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
for the Tandy TRS-80 line of 8-bit Zilog Z80
Zilog Z80
The Zilog Z80 is an 8-bit microprocessor designed by Zilog and sold from July 1976 onwards. It was widely used both in desktop and embedded computer designs as well as for military purposes...
microcomputers that were sold through Radio Shack
Radio shack
Radio shack is a slang term for a room or structure for housing radio equipment.-History:In the early days of radio, equipment was experimental and home-built. The first radio transmitters used a noisy spark to generate radio waves and were often housed in a garage or shed. When radio was first...
through the late 1970s and early 1980s. Tandy's manuals recommended that it be pronounced triss-doss. TRS-DOS should not be confused with Tandy DOS a version of MS-DOS
MS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
licensed from Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
for Tandy's x86 line of personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
s (PCs).
TRS-DOS was primarily a way of extending the MBASIC (BASIC
BASIC
BASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use - the name is an acronym from Beginner's All-purpose Symbolic Instruction Code....
in ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
) with additional I/O
I/O
I/O may refer to:* Input/output, a system of communication for information processing systems* Input-output model, an economic model of flow prediction between sectors...
(input/output) commands that worked with disk files rather than the cassette tapes that were used by most other TRS-80 systems.
TRS-DOS supported up to four floppy (mini-diskette) drives which used 5" (five and one quarter inch) diskettes with a capacity of 89K (kilobyte
Kilobyte
The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...
s) each (later 160K). The drives were numbered 0 through 3 and the system diskettes (which contained the TRS-DOS code and utilities) had to be in drive 0.
Commands
Some typical TRS-DOS utilities:| Command | DOS DOS DOS, short for "Disk Operating System", is an acronym for several closely related operating systems that dominated the IBM PC compatible market between 1981 and 1995, or until about 2000 if one includes the partially DOS-based Microsoft Windows versions 95, 98, and Millennium Edition.Related... , OS/2 OS/2 OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "Personal System/2 " line of second-generation personal... , Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal... |
Unix Unix Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna... , Unix-like Unix-like A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification.... |
|---|---|---|
| APPEND | type Type (command) In computing, type is a command in various VMS. AmigaDOS, CP/M, DOS, OS/2 and Microsoft Windows command line interpreters such as COMMAND.COM, cmd.exe, 4DOS/4NT and Windows PowerShell. It is used to display the contents of specified files... file1 >> file2 |
cat Cat (Unix) The cat command is a standard Unix program used to concatenate and display files. The name is from catenate, a synonym of concatenate.- Specification :... file >> file2 |
| ATTRIB | attrib Attrib attrib is a command, in DOS, OS/2 and Microsoft Windows. The function of attrib is to set and remove file attributes... |
chmod Chmod The chmod command is a Unix command that lets a user tell the system how much access it should permit to a file. It changes the file system modes of files and directories. The modes include permissions and special modes... |
| AUTO | AUTOEXEC.BAT AUTOEXEC.BAT AUTOEXEC.BAT is a system file found originally on DOS-type operating systems. It is a plain-text batch file that is located in the root directory of the boot device... |
~/.profile or ~/.login or /etc/rc* |
| BACKUP | diskcopy | tar Tar (file format) In computing, tar is both a file format and the name of a program used to handle such files... , cpio Cpio cpio is a general file archiver utility and its associated file format. It is primarily installed on Unix-like computer operating systems. The software utility was originally intended as a tape archiving program as part of the Programmer's Workbench , and has been a component of virtually every... , pax, (many others) |
| CLOCK | prompt $t * | in some shells: PS1 PS1 PS1, PS-1, PS/1 or PS One may refer to:* MoMA PS1 , American contemporary art institution* "$PS1": the environment variable in the Bourne shell and variants which specifies the command prompt.... ="...\t..." * |
| COPY | copy Copy (command) In computing, copy is a command in RT-11, RSX-11, OpenVMS, DOS, OS/2 and Microsoft Windows operating systems. The command copies computer files from one directory to another. The destination defaults to the current working directory. If more than one source file is indicated, the destination must... |
cp Cp (Unix) cp is a UNIX command used to copy a file. Files can be copied either to the same directory or to a completely different directory, possibly on a different file system or hard disk drive. If the file is copied to the same directory, the new file must have a different name to the original; in all... |
| DIR | dir | ls Ls In computing, ls is a command to list files in Unix and Unix-like operating systems. ls is specified by POSIX and the Single UNIX Specification.- History :An ls utility appeared in the original version of AT&T UNIX... |
| FORMAT | format Disk formatting Disk formatting is the process of preparing a hard disk drive or flexible disk medium for data storage. In some cases, the formatting operation may also create one or more new file systems... |
mkfs Mkfs mkfs is the Linux/GNU command for formatting a disk partition with a specific filesystem.- Syntax :The basic syntax is: mkfs -t type device... |
| FREE | chkdsk CHKDSK CHKDSK is a command on computers running DOS, OS/2 and Microsoft Windows operating systems that displays the file system integrity status of hard disks and floppy disk and can fix logical file system errors. It is similar to the fsck command in Unix.The command is implemented as an executable... |
df Df (Unix) df is a standard Unix computer program used to display the amount of available disk space for filesystems on which the invoking user has appropriate read access... |
| GETDISK/GETTAPE | dd Dd (Unix) In computing, dd is a common Unix program whose primary purpose is the low-level copying and conversion of raw data. According to the manual page for Version 7 Unix, it will "convert and copy a file". It is used to copy a specified number of bytes or blocks, performing on-the-fly byte order... |
|
| KILL | del Del (command) In computing, del is a command in various DOS, OS/2 and Microsoft Windows command line interpreters such as COMMAND.COM, cmd.exe, 4DOS/4NT and Windows PowerShell. It is used to delete one or more files or directories from a filesystem. It is analogous to the Unix rm command... |
rm Rm (Unix) rm is a basic UNIX command used to remove objects such as files, directories, device nodes, symbolic links, and so on from the filesystem... |
| LIST | type Type (command) In computing, type is a command in various VMS. AmigaDOS, CP/M, DOS, OS/2 and Microsoft Windows command line interpreters such as COMMAND.COM, cmd.exe, 4DOS/4NT and Windows PowerShell. It is used to display the contents of specified files... |
cat Cat (Unix) The cat command is a standard Unix program used to concatenate and display files. The name is from catenate, a synonym of concatenate.- Specification :... |
| LOAD program | (no equivalent) | (no equivalent) |
| type Type (command) In computing, type is a command in various VMS. AmigaDOS, CP/M, DOS, OS/2 and Microsoft Windows command line interpreters such as COMMAND.COM, cmd.exe, 4DOS/4NT and Windows PowerShell. It is used to display the contents of specified files... file >> prn |
lpr Line Printer Daemon protocol The Line Printer Daemon protocol/Line Printer Remote protocol is a network protocol for submitting print jobs to a remote printer. The original implementation of LPD was in the Berkeley printing system in the BSD UNIX operating system; the LPRng project also supports that protocol... |
|
| PROT | attrib Attrib attrib is a command, in DOS, OS/2 and Microsoft Windows. The function of attrib is to set and remove file attributes... |
chmod Chmod The chmod command is a Unix command that lets a user tell the system how much access it should permit to a file. It changes the file system modes of files and directories. The modes include permissions and special modes... |
| RENAME | ren Ren (command) In computing, ren is a command in various DOS, OS/2 and Microsoft Windows command line interpreters such as COMMAND.COM, cmd.exe, 4DOS/4NT and Windows PowerShell. It is used to rename files and in some implementations also directories. It is analogous to the Unix mv command... or rename Ren (command) In computing, ren is a command in various DOS, OS/2 and Microsoft Windows command line interpreters such as COMMAND.COM, cmd.exe, 4DOS/4NT and Windows PowerShell. It is used to rename files and in some implementations also directories. It is analogous to the Unix mv command... |
mv Mv mv is a Unix command that moves one or more files or directories from one place to another. Since it can "move" files from one filename to another, it is also used to rename files. Using mv requires the user to have write permission for the directories which the file will move between... |
- Notes:
- Since TRS-DOS didn't have the notion of redirection as UNIXUnixUnix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
/LinuxLinuxLinux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
and MS-DOSMS-DOSMS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
do, the APPEND command is somewhat different in concept than the UNIX or MS-DOS notion of appending via output redirection. - The CLOCK command display a real time clock in the upper corner of the display, almost like a DOS TSR (Terminate and Stay ResidentTerminate and Stay ResidentTerminate and Stay Resident is a computer system call in DOS computer operating systems that returns control to the system as if the program has quit, but keeps the program in memory...
); no exactly corresponding feature exists in MS-DOS or UNIX, though many programs provided similar features for DOS and the common UNIX shells could embed the time into their user defined "prompt string" - program invocation under TRS-DOS, DOS and UNIX is done by filename; no explicit LOAD command is required for normal binary executables nor for text command files (batch fileBatch fileIn DOS, OS/2, and Microsoft Windows, batch file is the name given to a type of script file, a text file containing a series of commands to be executed by the command interpreter....
s in DOS and shell scriptShell scriptA shell script is a script written for the shell, or command line interpreter, of an operating system. It is often considered a simple domain-specific programming language...
s in UNIX/Linux). The LOAD command under TRS-DOS would load a binary program into memory, but would not execute it; neither DOS nor UNIX has an equivalent. - Under DOS and UNIX printing a file can be done with redirection; under UNIX it's normally done by spooling the file to the "line printer" (using the lpr command) because UNIX is conventionally a multi-user system.
- ATTRIB, PROT, and the chmod UNIX command are all somewhat different in their semantics. UNIX/Linux is multi-user and each user can control read, write, and execute permissions on his or her own files and directories. MS-DOS is single user and the file attributes for "read-only," "hidden," and "system" are advisory in nature. TRS-DOS was single user but supported some sort of on disk password protection for specific files.
- The AUTO command set an automatic command to be executed on TRS-DOS boot; under MSDOS the special, reserved file named AUTOEXEC.BAT contained a list of such commands. On UNIX a set of one or more rc files under /etc/ are a set of boot time "run commands" and special "dot files" in a user's home directory are run for each time that a given user logs into the system. UNIX supports many other "dotfiles" for many of its commands which are akin to the Macintosh "preferences" folder contents.
- TRS-DOS (version II) was notable for the inclusion of noise words, similar to the 1959 COBOLCOBOLCOBOL is one of the oldest programming languages. Its name is an acronym for COmmon Business-Oriented Language, defining its primary domain in business, finance, and administrative systems for companies and governments....
specification. These made commands more English-like. For example, the following commands functioned identically:- COPY filea fileb
- COPY filea TO fileb
- Since TRS-DOS didn't have the notion of redirection as UNIX
- Many versions supported a simple password security for files and programs, with separate Read/Execute and full access capabilities. ex: filename/ext.password:drive#
Although MS-DOS owes its heritage most closely to CP/M
CP/M
CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...
and thence to TOPS-10
TOPS-10
The TOPS-10 System was a computer operating system from Digital Equipment Corporation for the PDP-10 mainframe computer launched in 1967...
, many of the file manipulation commands are very similar to those of TRS-DOS. By comparison the CP/M
CP/M
CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...
command for copying files was called pip (both a pun on the Pip printers, a chain of copy centers in that era, and an acronym standing for "Peripheral Interchange Program").
Dates
- May 8, 1979 - Radio Shack releases TRSDOS 2.3
- May 1, 1981 - Radio Shack releases Model III TRSDOS 1.3
External links
- Mike's Virtual Computer Museum: TRS-80
- TRS-80 Error Messages
- TRS-80 Revived Site
- Model III Home Page (with list of TRS-DOS alternatives on the TRS-80 Model III)
- Matthew Reed's TRS-80 Emulator Software Runs under MS-DOSMS-DOSMS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
; requires the extraction of a ROMRead-only memoryRead-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
image - xtrs A TRS-80 emulator for UNIX and X11; similar ROM issues apply
- TRSdisk - TRS-DOS utilities for UNIX
- TRS-80 Virtual Floppy Disk Manager
- TRS-DOS Applications