"The Atari A to Z" by Mark S Baines Copyright (c) 1998 Mark S Baines All Rights Reserved YOU MUST READ "READ_ME.NOW" BEFORE YOU LOOK AT ANY OF THIS FILE ***************************************************************************** T T Tera. Tab key The keyboard key performing a horizontal tabulation. TOS substitutes a default value of eight spaces for a Tab, whereas the norm for most programs is four or five. On some computers a [Shift-Tab] will give a left horizontal tabulation, but not on the ST-Falcon range. Tab The ASCII character 9 performing a horizontal tabulation. Table Synonymous with array in programming. Tabulation To move the printing position on a printer or the cursor on a screen to a preset position to the right (horizontal tabulation) or to a lower line position (vertical tabulation). TAF That's All Folks. Commonly used shorthand in e-mail and other messages. Tape A magnetic or paper storage medium, the latter practically extinct. Unless otherwise stated the former is understood. Tape deck The surface of a tape drive that is presented to the user, the part containing the reels of tape. Tape drive A magnetic tape unit. Most use tape cassettes or digital cassettes. Task A logical unit of work as performed on a computer. In a multiprogramming system, the basic unit to which resources are allocated. TCP/IP Transmission Control Protocol over Internet Protocol. The TCP/IP networking protocols are the de facto set of communication protocols for transferring data across networks of computers. TCP is a data transfer protocol and IP is the protocol for the format of that data. Data is split into chunks or packets and passed through the networks until it reaches its destination where it is reassembled into its original form. Each packet has a header containing information about its destination and its position in the overall file. TCP/IP has its origins in the DARPA experiments. DARPANET was using TCP/IP as its main transport protocol by 1974 but what really made it the standard was when the University of Berkeley implemented the DARPA Internet software for it 4.2BSD UNIX kernel. The resulting networking code was placed in the public domain and as a result practically all UNIX machines use TCP/IP. Once two machines are connected together using TCP/IP additional services are available which includes a virtual terminal session known as telnet. This allows any computer, even an ST, to act as a terminal for a distant UNIX machine. There are a number of file transfer utilities allowing files to be copied from one machine to another, the most common being ftp (File Transfer Protocol). There is the electronic mail transfer service, data routing and the remote execution of applications even using X Windows (a UNIX GUI) so that all the processing, file and memory accesses are done on the remote computer yet you see all the results as if it was all happening locally. Because UNIX is a multiuser, multiprogramming operating system, some or all of these services can be run simultaneously. Telecomms TELECOMMunicationS. The organization and facilities that provide a user-to- user communications service between two geographically separated sites, encompassing telephone, telegraph, radio and satellite-based systems although telephone is normally assumed. Telecommunications link A communications link between two sites through the lines and facilities of a telecommunication system. Telecommunications network A data network or the lines and facilities of a common carrier. Telecommuting Working from home or at a remote site from a company's main building and communicating with the main work place by telecommunications. Telemetering Using communication links to carry the outputs of sensors to a computer at another location to be recorded and analysed. Teleprocessing Data processing in which individual parts of the total function are performed at remote sites joined by communications links. Telesoftware Software distributed by Viewdata systems, such as Prestel. Teletex A word processor network designed to produce letter quality communications between subscribers. Teletext A system for broadcasting text material in conjunction with broadcast television during beam flyback time and decoded by special circuits in the receiving set. The text material is based on a 40 column by 25 line screen using eight colours and simple block graphics. Systems include Ceefax and Teletext on 3. Teletype A send and receive typewriter from the Teletype Corporation. Such typewriters act as a terminal in an asynchronous communications link. TELEX A worldwide, dial-up teletypewriter service provided by Western Union. Telnet A program operating under TCP/IP and used on the Internet to connect to a remote computer and perform some action there. Temporary file A scratch file, a data file usually overwritten at the end of the program execution. They may have the file name extender .TMP. Tera Prefix meaning a trillion (million million), 10^12. Terabyte 2^40 bytes, or 1,099,511,600,000 bytes. Terminal A device by which a user can communicate with a computer, such as a VDU or Teletype, usually remote and sometimes, dumb. The term is usually synonymous with 'station'. Also, a connector soldered or crimped to the end of a cable or a post or screw to attach to such a connector. Terminal program Some software enabling an intelligent computer to communicate with a remote host computer via a telecommunications network. Terminate To suspend or stop a program execution prematurely. Also, to connect resistors to the end of any data carrying cable to reduce or eliminate signal echoes. Terminate and stay resident See TSR. Ternary Systems with three possible states, all of which have data significance, such as a positive signal, a negative signal and the absence of a signal. Also, a numeration system with a radix of three. Test To check the function and operability of a program or electrical system. Test data Special input data designed to test the functionality of a program, causing it to follow all possible execution paths in an attempt to expose any errors. Test program A diagnostic program that is run to test hardware circuits for faults. Text Data in graphic character form as printed or displayed or as held in bit- pattern character form in storage. Also, that part of a message with significance in a data communications transfer. Text attributes The properties of text characters displayed or printed, such as those of alignment, emphasis, type of font etc. Text editor A program used to manipulate and structure textual data, usually not possessing the special formatting capabilities of a word processor. Straight ASCII files are normally produced with a carriage return and line feed character at the end of every line rather than just at the end of a paragraph as in a word processor. Such programs are useful for entering programming language source code or messages for transmission over a communications link. Text section One of the three sections of an executable program as produced by an assembler or compiler and linker. It contains the program's executable code. On the ST, TOS does not enforce any difference between data and text sections, the executable code can be placed in the data section without problems. Programs written taking advantage of this may not be portable to other operating systems and computers. See Basepage, BSS section, Data section. TFT LCD Thin Film Transistor Liquid Crystal Display. The technology used to manufacture LCD screens capable of greyscale or colour displays. Thermal matrix printer A printer with a print head containing electrically heated styli which, when pressed against special heat-sensitive paper, form a dot matrix character. They are inexpensive, quiet but produce very poor quality output. Thermionic Operating by thermal effect, such as vacuum tubes. Thin film transistor LCD See TFT LCD. Third-generation computer A computer using semiconductors in integrated circuits for data storage and manipulation, from 1964 up to the present. Some people add a fourth generation for the present day very large scale integrated circuits but as the technology is the same, such a designation is unwarranted. Threshold A level at which something becomes evident or detectable. Throughput The amount or work performed per unit time, such as instructions per second or bytes received down a communications link. In the latter, the true throughput is the total number of bytes per second after any necessary decompression of the file. Throw To move paper through a printer without printing, usually more than one line feed. Also, the amount by which the paper is moved. TIA Thanks In Advance. Commonly used shorthand in e-mail and other messages. TIFF Tag Image File Format. Bit-image file with a .TIF file name extender which is common on the PC and Macintosh. These files contain grey level or colour information which enables them to be manipulated and enhanced very easily. The file format is complex and produces large files, but the standard can cope with almost any resolution, image size and colour detail. Up until recently, the TIFF format was not catered for on the ST. Time base A repeating sequence of accurately spaced pulses of specified interval available in a computer or other device to control the synchronization of events. Time frame A unit of time in which an item of data can be sent and recognized by a receiving system in synchronous and asynchronous transfers. Time interleaving The allocation of a resource for a fixed, short interval of time to each of two or more entities in turn. See Multiprogramming. Time-out When a timer runs out and signals the end of that period in which an event can occur. It normally occurs because of the lack of a response from a peripheral unit or another station in a data link. Time sharing A multiprogramming, multi-user computer system that provides multiple users with their resources in 'time slices' on rotation or other method. Synonymous with time slicing and time interleaving. Time slice A short period of time in which a resource is allocated to a user in a multi- user system or a program in a multiprogramming system. Timer A device that provides regular time signals for controlling or synchronizing a sequence of events. Title bar The shaded or coloured box across the top of a GEM window containing the window title, which is normally a path name or the program's title. Dragging this bar will usually move windows to another screen location and in such cases is also called the mover bar. TLA Three Letter Acronym. An abbreviated title consisting of three letters used by all respectable jargon lovers! TNSTAAFL There's No Such Thing As A Free Lunch. Commonly used shorthand in e-mail and other messages. Token The smallest meaningful representation of a concept in a language consisting of a character group that loses its meaning if divided, such as the word 'Fred' or 'integer'. Tone dialling A telephone system using distinct sound tones rather than a series of 'clicks' to represent each dialled number. Toner The ink and resin powder which is passed onto the paper as the latter passes over the drum of a laser printer or photocopier. See Laser printer. Top-of-form The first line that is printed on a form or page of continuous stationery. Topped The uppermost and currently active window in a multi-window environment. See Active window. TOS The TOS executable file name extender. Such programs do not use any GEM features and use simple text displays often using VT52 screen control codes. TOS The Operating System and definitely not 'Tramiel Operating System'. The operating system of the Atari ST-Falcon range computers with more than a passing resemblance to MS-DOS. TOS consists of hardware dependent and hardware independent parts. The BIOS and XBIOS are hardware dependent, GEMDOS and GDOS being hardware independent. TOS14FIX.PRG An official freeware Atari patch program for TOS 1.4 only which should run from the AUTO folder. It solves the problems with the Rsconf() function RTS/CTS flow control without incurring any slowing down of data flow. It also deals with a bug in the shel_find() function which had the effect of a program sometimes being unable to find another file, such as its resource file. These were fixed for TOS 1.6. TOS version numbers The TOS version number is coded into the ROM at the address pointed to by the _sysbase system variable plus two longs (sixteen bytes). For TOS 1.0 the value in the ROM at this point is $0100 which is commonly interpreted as 01.00 or 1.00. Similarly, TOS 1.2 has the value $0102 and was, for many years, interpreted as v1.2. However, when TOS 2 and 3 came out the numbering system was changed to include the zero before the minor part of the version number, hence TOS 2.05 and TOS 3.06. Atari also decided to change the numbering system of earlier TOS versions retrospectively leading to much confusion which persists today. TOS 1.2, 1.4 and 1.6 therefore became TOS 1.02, 1.04 and 1.06. However, TOS 1.62 remains as such (and not 1.062!) as its ROM value is $0162. However, this version number implies a far greater upgrade from TOS 1.06 than actually took place. Numbers not in this list are third party modifications, such as TOS 1.41. Table T1: The TOS Version Numbers os_version Old New Name _sysbase+2 Number Number $0100 1.0 1.00 ROM TOS or Old TOS $0102 1.2 1.02 BLiTTER TOS or Mega TOS $0104 1.4 1.04 Rainbow TOS $0106 1.6 1.06 STE TOS $0162 1.62 1.62 STE TOS $0201 2.01 Mega STE TOS $0205 2.05 Mega STE TOS $0206 2.06 Mega STE TOS $0301 3.01 TT TOS $0305 3.05 TT TOS $0306 3.06 TT TOS $0400 4.00 Falcon TOS $0401 4.01 Falcon TOS $0402 4.02 Falcon TOS $0404 4.04 Falcon TOS TOS versions (official) DISK TOS - TOS 1.0 The very first STs actually came with TOS on disk. As some of these STs only had 256 K of RAM there wasn't much left for programs after TOS was loaded. Even a 512 K ST only had about 300 K left for accessories, AUTO folder and other programs. It is not supported by Atari any more. OLD or ROM TOS - TOS 1.0 The original ROM TOS, this version shipped in 520ST and 1040ST machines. It is basically the same as DISK TOS but has a newer version of the AES and GEMDOS. Formats: 192 K - two chip ROMs, six chip ROMs Machines: 520ST, 1040ST Atari Patch Utilities: FOLDRXXX.PRG MEGA TOS or BLiTTER TOS - TOS 1.2 or 1.02 This version of TOS first appeared on the Mega ST and fixes some minor problems in TOS 1.0 and has support for the BLiTTER chip and Real-Time Clock chip. Formats: 192 K - two chip ROMs, six chip ROMs Machines: 520ST, 1040ST, Mega ST2 and 4 Atari Patch Utilities: FOLDRXXX.PRG RAINBOW TOS - TOS 1.4 or 1.04 This is the last of the TOS versions that can be installed without major modifications to a pre-STE computer. It is available as an upgrade. It has much more robust and very much faster disk input/output especially seen with hard disks; faster disk copy; file move; file date stamp is preserved with copy/move; file archive attribute bit works; folders can be renamed; MS-DOS compatible disk format; improved file selector; auto-running of GEM programs at boot up; a fix for the 40 folder limit; Malloc() calls and OS Pool improved; file fastload bit for faster loading; more support for larger screens; keyboard reset and much more. Most of it was rewritten or recompiled to be much faster than previous versions of TOS. Formats: 192 K - two chip ROMs, six chip ROMs Machines: 520ST, 1040ST, Mega ST1, 2 and 4, Stacy Atari Patch Utilities: TOS14FIX.PRG, POOLFIX3.PRG, CACHEXXX.PRG, FOLDRXXX.PRG, MAKEFAST.PRG STE TOS, Rev 1 - TOS 1.6 or 1.06 TOS 1.6 is the TOS version that is shipped with the 1040STE and 520STE machines. It is essentially TOS 1.4 with support for the new hardware that the STE acquired. There is mouse support in the "Show File to Screen" function; the shel_find() bug in TOS 1.4 is fixed; palette size is now 4,096; 4-bit colour values; key click and bell sounds can be replaced by TSR routines; hard disk boot up delay; Rsconf() RTS/CTS bug fixed; introduction of a cookie jar; 8-bit stereo DMA sound support; two new controllers (light gun and paddle) support; external Genlock support; hardware support for vertical and horizontal scrolling. Formats: 256 K - two chip ROMs Machines: 520STE, 1040STE Atari Patch Utilities: STE_FIX.PRG, POOLFIX3.PRG, CACHEXXX.PRG, FOLDRXXX.PRG There is a bug in the Desktop code in this version of TOS that prevents the user from booting into medium resolution. The patch program STE_FIX.PRG will solve the problem. This version is only available in 1040STE and 520STE machines. It isn't available from Atari for upgrading. It won't work in older machines. STE TOS, Rev 2 - TOS 1.62 This is a slight revision of TOS 1.6. It fixes the POOLFIX problem in GEMDOS and the medium resolution boot up bug in the Desktop. Formats: 256 K - two chip ROMs Machines: 520STE, 1040STE Atari Patch Utilities: CACHEXXX.PRG, FOLDRXXX.PRG Mega STE TOS - TOS 2.02 TOS 2.02 is the first production version of TOS for the Mega STE using the much improved NewDesk Desktop from the TT with many features from Gribnif's NeoDesk Desktop replacement. TOS 2.0x is essentially similar to TOS 3.0x without the TT specific features, such as Fast RAM support and extra resolutions, and differs from TOS 1.62 in providing support for the extra Mega STE hardware. The RTS/CTS serial port bug was reintroduced and further ones concerning parity and word size in the SCC serial ports. Also the Iorec(0) function doesn't work properly. Formats: 256 K - two chip ROMs Machines: Mega STE1, 2 and 4 Atari Patch Utilities: CACHEXXX.PRG, FOLDRXXX.PRG, SERPTCH1.PRG Mega STE TOS - TOS 2.05 TOS 2.05 is the version of TOS for the Mega STE that was present in most early production machines. The RTS/CTS serial port bug was reintroduced and further ones concerning parity and word size in the SCC serial ports. Also the Iorec(0) function doesn't work properly. Formats: 256 K - two chip ROMs Machines: Mega STE1, 2 and 4 Atari Patch Utilities: CACHEXXX.PRG, FOLDRXXX.PRG, SERPTCH1.PRG Mega STE TOS - TOS 2.06 TOS 2.06 is the final version of TOS for the Mega STE. Changes include: Atari logo displayed at boot-up; automatic memory test at cold boot; hard drive start-up time delay; install programs, folders or files on the Desktop as icons; change resolution with [Alt-number] key commands; all available drives can be installed in one operation; icons can be set to automatically fit within a window; background colour of Desktop and windows is user configurable; user selected icons can be assigned to devices or files; files can now be moved, moved and renamed, or copied and renamed in one operation; windows can be scrolled with files selected; select all files in a window command; the serial port (RTS/CTS flow control and SCC) is fixed; start programs with function keys; file copy any drive by dragging drive icons; bypass AUTO and accessory programs by holding down the [Control] key at boot up; enter special characters using [Alt-numberpad] combinations; file search function; file masks supported; multiple Desktop configurations supported; print contents of top window or directories as ASCII text; directory window "No Sort" option; seven windows allowed; bottom window can be brought to top; keyboard commands available for most Desktop functions; keyboard commands user configurable; [Help] key support included; software support for 1.44 Mb floppies; 6 ms floppy disk step rate; improved media change detection. Formats: 256 K - two chip ROMs Machines: Mega STE1, 2 and 4, ST Book Atari Patch Utilities: CACHEXXX.PRG, FOLDRXXX.PRG TT TOS - TOS 3.01 TOS 3.01 was the first version of TOS for the TT030 introducing the much improved NewDesk Desktop with many features from Gribnif's NeoDesk Desktop replacement. All GEMDOS memory including that from accessories is freed on resolution change; the menu/alert box screen buffer is now half the screen; all window elements can be individually coloured; support for Fast 32-bit RAM; extra resolution support; mapping of the serial ports; support for .GTP (GEM Takes Parameters) programs; new XCONTROL panel accessory. The RTS/CTS serial port bug was reintroduced and further ones concerning parity and word size in the SCC serial ports. Formats: 512 K - four chip ROMs Machines: TT030 Atari Patch Utilities: CACHEXXX.PRG, FOLDRXXX.PRG, SERPTCH1.PRG TT TOS - TOS 3.05 TOS 3.05 is the version of TOS for the TT030 that was present in most early production machines. The RTS/CTS serial port bug was reintroduced and further ones concerning parity and word size in the SCC serial ports. Formats: 512 K - four chip ROMs Machines: TT030 Atari Patch Utilities: CACHEXXX.PRG, FOLDRXXX.PRG, SERPTCH1.PRG TT TOS - TOS 3.06 TOS 3.06 is the final version of TOS for the TT030 which includes support for high density floppy disks; boots up in 640 x 480 resolution with access to 320 x 200 mode by pressing the [Alternate] key; a memory check after a cold boot; VDI BitBLT greatly improved; bypass of AUTO programs and accessories at boot- up; media change detection on floppy disks is better; enter special characters using [Alt-numberpad] combinations; less floppy spin up delay; empty drives detected sooner; floppy disks with only one FAT supported; serial port (RTS/CTS flow control and SCC) is fixed; MC68882 reset at boot-up; greater compatibility for programs using Timer-A; multiple AES events when scrolling are reduced. Formats: 512 K - four chip ROMs Machines: TT030 Atari Patch Utilities: CACHEXXX.PRG, FOLDRXXX.PRG FALCON TOS - TOS 4.01 This was the pre-production version of the TOS for the Falcon and caters for the new hardware and video differences, especially the 16 MHz BLiTTER, DSP, SoundDMA and video functions libraries. A new AES is rewritten to support hierarchical menus, pop-up menus, 3D window and dialog objects, 256 colours 'animated' icons and soft-loaded fonts. It is also multitasking aware and provides facilities for linking with MultiTOS, with 'drag and drop' across applications, extensible file system support and background window manipulation. The VDI has the necessary support for all the Falcon video modes including overlay. The usual GEMDOS, BIOS and XBIOS functions are also contained in the TOS ROM. However, the multitasking kernel and other utilities of MultiTOS are ram-loaded from disk making upgrades easy. TOS 4 contains all the data relative to all the different countries and keyboard layouts with a CPX module to configure the system, the language selection being stored in non-volatile RAM. The countries/languages catered for are USA, UK, Germany, Spain, France, Italy, Swiss French, Swiss German. Hard disk spin delay is configurable via NVRAM. Although pre-production, this version was released in early Falcons and has some very serious bugs in it, an updated SHDRIVER.SYS file is necessary as is FPATCH2.PRG. Formats: 512 K - one chip ROM. Machines: Falcon030 Atari Patch Utilities: CACHEXXX.PRG, FOLDRXXX.PRG, FPATCH1.PRG, FPATCH2.PRG FALCON TOS - TOS 4.02 Early production Falcon TOS. This version still contains the serious bugs, an updated SHDRIVER.SYS file is necessary as is FPATCH2.PRG. AES 3D objects now uses more compatible ob_state flags rather than extended type. Formats: 512 K - one chip ROM. Machines: Falcon030 Atari Patch Utilities: CACHEXXX.PRG, FOLDRXXX.PRG, FPATCH1.PRG, FPATCH2.PRG FALCON TOS - TOS 4.04 Current production Falcon TOS. The bug that prevented sound calls working with external clock sources is cured. Devconnect() bug fixed. Formats: 512 K - one chip ROM. Machines: Falcon030 Atari Patch Utilities: CACHEXXX.PRG, FOLDRXXX.PRG, FPATCH1.PRG, FPATCH2.PRG MultiTOS Multitasking TOS based on MiNT. This is the pre-emptive multitasking TOS based on the freeware MiNT project introduced on the Falcon030. It essentially provides a multiprogramming environment in protected mode on a MC68030 running GEM programs under the NewDesk Desktop or any other shell, such as Mintshel and TOS programs from within windows, such as MINIWIN or MW so that they don't take over the whole screen. Many applications can be open and visible on the Desktop at the same time, and the priority of a program (see Multiprogramming) can be altered, thus increasing its speed of operation although to the detriment of the other processes, of course. MultiTOS will also work on a MC68000 machine (loading up the multitasking AES and NewDesk Desktop from disk) but without memory protection because the 68000 does not provide those facilities. Essentially, MultiTOS is an extension to TOS 4 on the Falcon and is available for other computers. Being disk-based allows for the easy incorporation of maintenance releases and upgrades. Formats: Disk-based RAM-loaded system Machines: Primarily Falcon030 and TT but also ST and STE There has been a version of TOS in the UK under the version number of 1.09 which has caused much confusion over the years. TOS 1.09 appeared in late 1987 as an Atari UK version of TOS 1.2 in answer to the Mega ST and the provision of the BLiTTER. Atari UK named it TOS 1.09 but Atari US would not make this number official. TOS 1.09 was replaced soon after with the official TOS 1.2. TOS Tape Operating System. An operating system for old IBM System/360 computers held on magnetic tape and no relation! TPA Transient Program Area. TPI Tracks Per Inch. A unit of measurement of track density on a disk. Trace Also log, a record of a series of events as they occur. Also, a listing of the instructions of a program in the order of execution. Trace error The CPU can be set to jump to a specific address after every machine instruction is executed. This address is normally used by programmers using debuggers to step through a program. If this address has not been set and a trace does occur then this processor exception is generated resulting in nine bombs. See Exception vectors, Bombs. Trace program A program used to monitor the execution of another, logging each instruction and showing its result before passing on to the next, usually under user control. It is normally used as a debugging aid for a programmer. Track A thin path on a magnetizable surface medium where data can be or has been written. On a TOS formatted disk, there are 80 tracks numbered 0 to 79 each containing nine sectors. See Sectors, Cylinders. Track density The number of tracks per inch (measured along the radius) of a recording surface, typically 135 TPI on a 3.5 inch floppy disk. It is the width of these tracks that mostly accounts for the storage capacity of a disk, for the thinner they are the closer they can be placed together and the higher the density on hard disks. Track number The number by which a track can be identified. Track 0 is at the outer edge of the disk with the highest numbered one nearest the centre. In a hard disk with multiple surfaces, the track number is also the cylinder number. Track trimming The operation of removing excess magnetization patterns at the sides of tracks on disks as they are recorded in order to permit closer track spacing and to prevent the interference of the magnetization patterns from adjacent tracks. Tractor The two sets of rotating teeth on many line printers that engage the holes at the edge of continuous stationery, thus moving it vertically past the print head. Trailing zeros Zeros to the right of the least significant non-zero digit in a numeric string, such as 1.25000. Train A sequence, a group of items following one after another. Transaction In an on-line system, an interchange between a user and the computer. Also, an enquiry. Also, a 'job' in batch processing system or the record that causes the updating of a master file. Transaction file A record of all interchanges at a computer terminal used to update a master file, or for charging and/or statistical purposes. Transceiver A device that can both transmit and receive, such as a modem or telephone. Transcribe Synonymous with copy. To read data in one location and write it to another, often with a change of medium or representation, such as from paper to a disk file. Transfer Synonymous with move. To read data in one location and to write it to another, usually on a different medium and device. The term sometimes denotes a change of location often with the deletion of the original copy. Transfer control To discontinue executing the instructions of one sequence and to commence executing those of another. Transfer rate The data transfer rate. Transfer time The time between the reading of a bit from a source location and the completion of writing it to a destination location. This is one of the most important measurements of the performance of a storage medium, such as a hard disk. Transform To change the form of data in such a way that the original can be reconstructed by a reversal of the operation, such as in a decimal to binary conversion. Transformer An electromagnetic device used to change the voltage of alternating current, say from 240 V to 12 V. Transient Not always present or occurring at unpredictable intervals. Also, in process of change from one mode to another and an unpredictable short duration change in a circuit condition. Transient program area - TPA That area of RAM reserved for user programs loaded from disk. It is the greater part of memory left over after the operating system has allocated all its own resources, such as the first 2,048 bytes for system variables and exception vectors, the screen memory and other registers. Transistor A common semiconductor switch or amplifier. Transistor-transistor logic See TTL. Transition A change from one condition to another. Translate Usually a compiler or assembler operation of changing program source code into object code. Translator A program, such as a compiler or interpreter, used to convert source code into object code. Transliteration A code conversion, a change of the bit-patterns used to represent the characters of a set. Transmission The sending of data over a communications link between geographically separated locations. Transmit To send data from one location to be received elsewhere. Transmitter A device that can generate and send signals representing data or speech. Transparent Any functional unit or computer operation that is not evident to the user. The idea behind a GUI or WIMP system is to make as much of the operating system of a computer as transparent as possible taking the user away from the rigid command line structure of alternative interfaces. Trap An unprogrammed conditional jump, a jump that occurs when an operating system routine detects a particular processing condition, such as a disk error, parity error, memory protection violation. The jump is usually to some interrupt routine with provision made to hold the address from which the jump was made so that control can return to that point. TRAP An instruction of the ST-Falcon range used to cause a MC680x0 processor exception to occur. The processor jumps to the start of a routine, the address of which is stored at the appropriate exception vector location returning control to the original calling routine when finished. Sixteen of the exception vectors are TRAPs for use by user programs and the operating system of which four are the most commonly used. GEMDOS functions are called with a TRAP #1, for instance. Table T2: The TRAP Exception Vectors Exception Address TRAP No Vector 32 $080 TRAP #0 33 $084 TRAP #1 - GEMDOS function call 34 $088 TRAP #2 - AES/VDI function call 35 $08C TRAP #3 36 $090 TRAP #4 37 $094 TRAP #5 38 $098 TRAP #6 39 $09C TRAP #7 40 $0A0 TRAP #8 41 $0A4 TRAP #9 42 $0A8 TRAP #10 43 $0AC TRAP #11 44 $0B0 TRAP #12 45 $0B4 TRAP #13 - BIOS function call 46 $0B8 TRAP #14 - XBIOS function call 47 $0BC TRAP #15 TRAPV instruction A processor exception also known as an overflow error that is caused by a special instruction of the MC680x0 called a TRAPV instruction. If a program tries to add two numbers whose result is too big for the available storage space, then an overflow is said to have happened. If a compiler or programmer places a TRAPV instruction after an ADD instruction, then this exception error occurs whenever an overflow results. See Exception vectors, Bombs. Trash can A WIMP environment icon representing a files delete function. When file icons are dragged to this icon they are deleted from the disk. It can also be used to remove icons placed on the Desktop, such as under the NewDesk Desktop. Under GEM, the files are normally irrecoverable. On the Macintosh, they are retrievable. Tree A hierarchical structure of entities and often a hierarchical net or multilevel data structure, such as a disk filing system, a family tree or pedigree or a data network. See Root, Owner or Member. Tree diagram A graphical representation of a hierarchical structure. Triad A group of three entities. Tribit Three bits treated as one unit, for instance three bits transmitted in one Baud in a data transfer. Trigger To initiate an action or operation. Triplet Three entities, usually contiguous. Tristate Capable of assuming three different states. The data and address lines on the MC68000 are tristate, effectively on, off and disconnected, the latter allowing other devices to take over the buses. Troubleshooting The operations performed to locate and correct faults in equipment or procedures. True One of two possible logic conditions, typically represented as a 1-bit or the value one or greater. TrueType fonts The most commonly used scalable font system. Originally the internal font system for the Apple Macintosh, it was included in later versions of Windows for the PC. The language in which the font outlines are stored is easy to use and the files can hold a lot of compressed data for a wide variety of output devices. They are also cheap, widely available and abundant. Truncate To remove leading or trailing digits from a number without regard to the effect upon the remaining digits. Also, to shorten a string by removing elements from the end which may be intentional or accidental, such as writing data to a location too short to accommodate it. See Round. Truncation error An error in numeric data introduced by truncation. See Rounding error. Trunk A major data transfer path within a communications system either in a data network or within a computer system. Truth Either of the two possible input or output states of a logic operation, 'true' or 'false'. Truth table A table that gives the output of a logic operation for each possible input combination. TSR Terminate and Stay Resident. A program which, once loaded, remains dormant until called upon by the user or continues to run in the background usually under interrupts on a singletasking system. Many AUTO folder programs and accessories are TSRs and constitute a form of multiprogramming, although their use is rather redundant under a true multiprogramming system, such as MultiTOS. TT Thirtytwo, Thirtytwo. A development of the Atari ST computer utilizing a 32 MHz 32-bit MC68030 processor, hence the name. Features include a MC68882 floating point maths coprocessor, the use of 32-bit wide Fast RAM, SCSI, LAN and high-speed serial ports and a slave only VME bus. Of particular note is the extended colour resolutions with a VGA mode of sixteen colours at 640 x 480 pixels, and 320 x 480 x 256 colours, as well as the ST modes. The ST high resolution mode is duochrome, where any two colours can be used rather than just black and white as on the ST. A TT high resolution monochrome mode of 1,280 x 960 is produced by a National DP8516 graphics processor using ECL circuitry. The sound subsystem is the same as that on the STE. There is a separate keyboard similar to the Mega ST and Mega STE and a hard disk within the main casing, which can easily be upgraded to a larger one. The standard TT comes with 2 Mb of dual purpose ST RAM on the motherboard and an expansion card can be added with another 2 Mb or 8 Mb making 10 Mb in all. Also expansion cards containing Fast TT RAM of 4 Mb or 16 Mb can be bought, which are 32 bits wide. All expansion cards contain the relevant MMU as well as the RAM chips. Memory can also be installed in the VME slot but it is not appropriate to put system expansion RAM there as it is meant to be for hardware peripherals only. A large RAM capacity, high resolution modes and the ability to run UNIX make the TT a versatile workstation. The TT was initially designed to run at 16 MHz but after a long germination period this performance was disappointing to all who saw it. Almost immediately, the 16 MHz 68030 was replaced with a 32 MHz processor and the MC68881 was replaced with a 68882. However, the rest of the bus still operates at 16 MHz and because the 68030 has small on-chip caches (256 bytes data and instruction) the overall performance of the TT is not as good as its technical specifications suggest. A speed increase of only about 30% was found rather than 70-80% which was expected. See DMA sound, ST RAM, Fast RAM, TT UNIX system, TT video, VME. Table T3: TT Specification Processor 32 MHz MC68030 separate on-chip 256 byte instruction and data caches 16 MHz MC68882 Floating Point Processor DMA Bus Full 32-bit, data and address RAM 2 Mb ST dual purpose, expandable to 4 or 10 Mb 4 or 16 Mb TT burst mode Fast RAM optional ROM 4 socketed 1 Mbit ROMs providing 512 K of ROM space Hard Disk Drive Internal SCSI 52 Mb, 120 Mb, 240 Mb, 420 Mb (sizes change with availability) Floppy Disk Drive 3.5" double-sided high density 1.44 Mb Input/Output MIDI in and out (5-pin DIN) Monitor port (15-pin VGA) for analog RGB colour monitor or ECL monochrome monitor Parallel printer port 2 asynchronous serial ports from two MFP 68901 (9-pin DB) 2 high-speed SCC serial ports (9-pin DB) one of which can be programmed as a LAN interface with single channel DMA controller SCC LAN with DMA (8-pin mini-DIN) SCSI with DMA (25-pin connector) Atari ACSI with DMA External floppy disk drive port with ACSI DMA ST compatible cartridge port (128 K) Separate keyboard interface 2 stereo sound output RCA-style phono sockets Internal VME bus (single Eurocard A24/D16 and A16/D16 slave only interface) Video Colour palette of 4,096 colours 320 x 200 x 16 colours ST low resolution 640 x 200 x 4 colours ST medium resolution 640 x 400 x 2 colours ST high resolution duochrome 320 x 480 x 256 colours TT low resolution 640 x 480 x 16 colours TT medium resolution 1,280 x 960 x 2 TT high resolution monochrome 80 column text display (40 in low resolution) Colour modes 60 Hz, Monochrome 67 Hz Hardware assisted scrolling External Genlock support Sound Total MIDI compatibility Stereo 8-bit PCM DMA sound (STE compatible) 3 channel PSG sound (ST compatible) Internal mono speaker (which can be disabled) Keyboard Separate QWERTY keyboard, 95 keys, numeric keypad, 10 function keys, cursor keys, mouse port (9-pin DB), joystick port (9-pin DB) support for 3 button mouse Mouse 128 dpi 2 button Real-Time Clock Battery backed with 50 bytes of non-volatile RAM Power Internal PSU Operating System TOS 3 with GEM and NewDesk Desktop in ROM AT & T UNIX System V was optional TTFMCU TT Fast Memory Control Unit. The memory controller chip on the Fast TT RAM expansion board for the TT. It controls the Fast RAM only taking a 16 MHz clock signal and address lines from the motherboard connector. There are separate jumpers to select the start address of this RAM which is normally $01000000 and another switch selects burst or nybble mode. Also called TTMMU. See Fast RAM, MMU, MCU. TTFN Ta Ta For Now. Commonly used shorthand in e-mail and other messages. TTL Transistor-Transistor Logic. A family of common semiconductor memory and logic integrated circuits with high-speed and low power dissipation. TTM194 An Atari 19 inch monochrome monitor for the TT with up to 1,280 x 960 resolution. Sometimes known as the SM194. TTM195 An Atari 19 inch monochrome monitor for the TT with up to 1,280 x 960 resolution. Sometimes known as the SM195. TTMMU TT Memory Management Unit. The MCU chip that manages the TT Fast RAM on its expansion board also called the TTFMCU. See TTFMCU, Fast RAM. TTP Tos Takes Parameters. The Atari executable program file name extender indicating that the program can take parameters from a command line. Calling such a program results in the display of a dialog box with a command line for entering these parameters and commands. These programs are generally intended to be used from within a shell, in particular command line interfaces. TT RAM See Fast RAM. TT UNIX workstation A TT030 with 18 Mb RAM, 340 Mb hard disk drive, three button mouse and TTM195 19 inch monochrome monitor with Atari's UNIX implementation of AT&T System V Release 4.0 for the Motorola 68000 series and Atari's workstation graphical user interface based on the hardware and operating system independent X Window System Release 11.4, Open System Foundation (OSF)/Motif style user interface, XFaceMaker and WisH2 Desktop manager. The Free Software Foundation GNU C and C++ compilers and GNU and AT & T System V debuggers are also provided for developers. Connection to other workstation networks is provided with an optional VME Ethernet card. Some question whether the TT is fast enough to handle UNIX with a processor intensive front-end like X Windows to be comfortable enough. The monochrome monitor is also underpowered as X Windows is better using 256 colours or grey scales. Although a few systems were released, copyright and development problems lead to the early demise of this project which would have radically cut the cost of a UNIX workstation. TT video The TT video subsystem was designed to extend the existing ST modes. Additional modes were designed to allow more colours and larger screen sizes. Table T4: TT Video Modes ST mode Mode Resolution Planes Colours Palette CLUT entries and DACs 00 320 x 200 4 16 512, 3 bits 01 640 x 200 2 4 512, 3 bits 10 640 x 400 1 - Monochrome TT mode Mode Resolution Planes Colours Palette 000 320 x 200 4 16 4,096, 4 bits 001 640 x 200 2 4 4,096, 4 bits 010 640 x 400 1 2 4,096, 4 bits - Duochrome 011 reserved 100 640 x 480 4 16 4,096, 4 bits 101 reserved 110 1,280 x 960 1 - Monochrome 111 320 x 480 8 256 4,096, 4 bits Each mode is set up via the respective ST or TT Shift Mode Register. In the ST mode, sixteen word-wide registers comprise the ST Colour Palette also known as the Colour Look Up Table (CLUT). Each entry contains nine bits of colour data, three bits each for red, green and blue, making a total of 512 possible colours to select from. Mode 00 (320 x 200 x 4) can index all sixteen colours, whilst mode 01 (640 x 200 x 2) can index just the first four palette colours. The monochrome mode is provide with an inverter for inverse video controlled by bit 0 of palette colour 0. In multi-plane modes, colour 0 is also used to assign a border colour. Additional modes are available by programming the TTSHIFTER through the TT Shift Mode Register. There is a maximum of 256 TT Colour Palette Registers each containing twelve bits of colour data, four bits each for RGB, making a total of 4,096 possible colours to choose from. Through the ST Palette Bank (lowest four bits of the TT Shift Mode Register) one of sixteen banks may be selected from the TT Colour Palette for use in ST modes. This allows modes 000, 001, 010 and 100 to seemingly select from up to 256 registers by setting the palette bank. Only mode 111 (320 x 480 x 8) can directly index all 256 registers. Duochrome mode allows the display of any two programmable colours rather than being limited to just black and white. TT Palette Register 254 is normally used for the '0' colour and Register 255 for the '1' colour. This mode can be inverted. Hyper Mono is a special mode where the output of two DACs are combined to give eight bits of control of the level of all three guns. The green output from the selected colour palette entry provides the most significant four bits and the blue output provides the least significant four bits. The video display memory is configured as logical planes (1, 2, 4 or 8) of interleaved 16-bit words of contiguous memory to form one 32,000 bytes (ST modes) or 153,600 bytes (TT modes) screen buffer starting at any eight byte boundary in ST RAM only. TTVIDEO The TT SHIFTER chip. On the TT the SHIFTER was converted to allow for the greater colour palette and enhanced colour video modes. It is an 84-pin PLCC chip and is normally socketed. Besides the red, green and blue colour signals, it also produces the HSYNC, VSYNC and DE signals. See RGB, SHIFTER. TTY TeleTYpe. Also refers to any dumb, alphanumeric text terminal. Tuning The process of optimizing the performance of an operation, usually with respect to speed. TurboNet An international bulletin board system network catering specifically for the Atari range of computers, although some conferences are more general. It evolved from the FNet (ForemNet) in 1992. Twisted format Twisted disks have sectors on successive tracks offset from one another when formatted, introducing a sector interleave. Instead of always starting sector 1 at the index mark, they start sector 1 on track 0, sector 3 on track 1, sector 5 on track 2, and so on. This makes disk read and writes faster because there are only two sectors of latency between reading sector 9 from track 0 and sector 1 of track 1, instead of 9 sectors of latency waiting for the whole disk to spin around. The Desktop disk format has been twisted since TOS 1.2. See Interleave. Twisted pair A two-wire insulated cable constituting a two-wire circuit commonly used in cheaper local area network cabling. Two-way communication A duplex or half-duplex communications system. Tx (TX TxD TXD) Shorthand for transmit or transmitter. TXT The file name extender of an ASCII text file, without any word processor formatting codes inserted. Such files normally have a carriage return and line feed character at the end of every line. See ASC. TYG There You Go. Commonly used shorthand in e-mail and other messages. Type In classification, the attributes by which entities are allocated to a group. Also, to print using a typewriter or to enter data into a computer via a keyboard. In printing, the embossed, metallic, shaped characters used to form characters on a page when inked and pressed against the paper. Type face A named style of letterforms such as Times or Helvetica, consisting of a family of fonts, that is, of different styles and sizes. Type font A set of letterforms of the same size and style in type, photographic or computer bit representative form, such as 12-point Times Italic. Type fount Same as type font. Typewriter A manually operated impact character printer. T 149 entries EOF