Millennium Time Capsule

home *** CD-ROM | disk | FTP | other *** search

/ Millennium Time Capsule / AC2000.BIN / disks / ac10disk / atozbook / f.txt < prev next >

Wrap

Text File | 1998-06-10 | 58KB | 1,228 lines

"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 ***************************************************************************** F Face The term used to refer to graphic characters to identify type or style, as in italic face. Facsimile See FAX. Fail safe To fail in such a way so that no data loss or dangerous condition results. Failure A complete loss of a function or facility. Falcon030 The Atari Falcon030 is the latest of the Atari range of TOS compatible computers using a 16 MHz MC68030 processor (switchable to 8 MHz), an optional MC68881/2 FPU, a 16 MHz BLiTTER and a 32 MHz Digital Signal Processor (DSP). There is a 512 K ROM and up to 16 Mb of RAM (2 Mb of the 16 Mb is masked out as a ST memory map image and I/O space to retain downwards compatibility and direct peripheral and DSP memory mapping) with an optional internal 2.5 inch hard disk drive and a 1.44 Mb HD floppy disk drive. Two internal expansion slots are provided, one for the memory card and the other is the processor direct slot for third party expansion boards, such as for IBM PC 386 emulation and JPEG and MPEG video boards. The RAM expansion board is custom designed and has 32 sockets that can accept either eight 256 K x 4 DIP DRAMs at 80 ns, or eight 1 Mb x 4 DIP DRAMs at 80 ns, or 32 1 Mb x 4 DIP DRAMs at 80 ns, giving 1, 4, or 16 (14) Megabytes of RAM, all on one board. TOS 4 and MultiTOS are used with the NewDesk Desktop and the Falcon is TOS compatible. Many other ports are similar to those of the Mega STE and TT. What particularly makes this computer interesting is the very sophisticated digital processing and audio subsystem. Eight track, stereo 16-bit digital input and output via stereo jacks are available with sampling rates up to 50 kHz (better than CD quality sound), making direct sampling to disk possible with software! The inclusion of the DSP gives very fast processing of any digital data independent of the CPU, so that as well as digital sound manipulation, images and graphic material can also be processed with speed. The video output is VGA standard with a resolution of 640 x 480 and 256 colours. The true-colour modes are 16-bit 640 x 480 x 65,536 colours (interlaced on TV or ST style monitors) and 15-bit overlay 640 x 480 x 32,768 mode which allows for easy video titling and special effects. True-colour 320 x 480 is available on VGA monitors. ST compatible modes are also available. All video modes are capable of being Genlocked to provide multimedia capabilities on monitors and television and the true-colour modes directly support overlays. Programmable overscan is also available so that the 320 x 200 x 256 colour display can give a 384 x 240 screen and the highest resolution is 768 x 480 with overscan in true-colour mode. The first Falcon030s came in a dark grey 1040STE style case but later versions reverted to the Atari grey colour. The style of case has always been generally disliked by developers and customers. At one point a 'consumer' version featuring a new casing was expected as was a two-piece, separate keyboard version. Both are now unlikely to appear from Atari. The Falcon040 has also been spoken about and apparently in development at Atari at one time, and was to cater for the business and serious home user. It would have used a fast 68040 CPU, had more RAM and existed in a more traditional three-box case like that of the TT. There has been much argument about the sizes of the data and address buses on the Falcon. All Atari documents say that the bus is 32 bits wide. However, examination of the motherboard suggests that the address bus is only 24 bits wide for the RAM expansion slot only has that number of lines. The data bus is generally 16 bits wide into and out of the CPU but the connection between the COMBEL and VIDEL chips and the RAM is 32 bits wide. The 68030 CPU therefore has to do dynamic bus resizing to get a 32-bit word as two 16-bit words. The video data is taken from the 32-bit wide side of COMBEL enabling a higher bandwidth suitable for the high resolution/colour modes. Argument also continues on Atari's definition of true-colour, whether true- colour can be anything less than 24-bit colour. In December 1994, it was announced that C-LAB Digital Media (a German company that released Notator, Creator and Unitor) had signed a worldwide licence agreement to manufacture, market and distribute workstation products based on the Falcon into the professional audio and musical instrument markets. The first machine they aim to produce (at the time of writing) is a standard Falcon with professional quality audio circuitry (what are currently referred to as the Cubase mods) and adequate memory and SCSI hard drive capacity. It is known as the C-LAB Falcon Mk II. They also hope to have a cheap entry level machine and a 68040 prototype is supposedly in an advanced stage as well as an enhanced Desktop and a 19 inch rackmount version. This development confirms the view of many that Atari's future lies with games machines, such as the Jaguar, and that they have no plans to produce any more computers for the foreseeable future. See Falcon video. Also see DMA sound, Sampling, DSP, MultiTOS, Expansion bus, Falcon video, Falcon audio. Table F1: Falcon Specification Processor 16 MHz MC68030 separate on-chip 256 byte instruction and data caches Optional 16 MHz MC68881/2 FPU 32 MHz MC56001 Digital Signal Processor 16 MHz 16-bit BLiTTER DMA Performance 3.84 MIPS Bus Two independent 32-bit data and 24-bit address buses RAM 1, 4 or 14 Mb operating in page mode, 32-bit wide but not nybble/burst mode as in TT RAM ROM 1 socketed 4 Mbit ROM providing 512 K of ROM space Hard Disk Drive Internal optional 2.5" drives on IDE bus, 65 Mb, 85 Mb, 120 Mb, 200 Mb Floppy Disk Drive 3.5" double-sided high density 1.44 Mb Input/Output MIDI in and out (5-pin DIN) Analog RGB monitor port (19-pin DB VGA) for VGA monitors, ST monochrome or colour monitors (via adaptor plug) with Genlock support RF modulator for TV or video (RCA) Bidirectional parallel printer port (25-pin DB) High-speed SCC serial port (9-pin DB) SCC LAN (8-pin mini-DIN) SCSI II with DMA (50-pin connector) ST compatible cartridge port (128 K) 2 digital/analog controller ports (15-pin DB) ST joystick (9-pin DB) ST mouse (9-pin DB) Digital audio/DSP connector (26-pin DB) Stereo microphone input (mini-jack) Stereo headphones output (mini-jack) Internal RAM board slot (30 + 50-pin) Processor direct slot (30 + 50-pin) Internal IDE hard disk connection (44-pin) Video See Falcon video. Some examples: 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 TV/video colour palette of 262,144 colours 640 x 400 x 65,536 colours (16-bit) 640 x 400 x 32,768 colours (15-bit overlay mode) VGA palette of 262,144 colours 640 x 480 x 256 colours 320 x 480 x true-colour Programmable overscan All modes can be Genlocked. True-colour modes support overlays Hardware assisted fine scrolling Sound Stereo 16-bit digital DMA audio output Stereo 16-bit digital DMA audio input 8 channel 16-bit PCM digital record/playback Stereo 8-bit PCM sound (compatible with TT, STE and Mega STE) 3 channel PSG sound (compatible with ST) Total MIDI compatibility Internal mono speaker (which can be disabled) Keyboard Integral QWERTY keyboard, 95 keys, numeric keypad, cursor keys, 10 function keys, (support for 300 dpi mouse) Mouse 128 dpi 2 button Real-Time Clock Rechargeable battery backed RTC with 50 bytes of non- volatile RAM Power Internal PSU Operating System TOS 4 with GEM and NewDesk Desktop in ROM Falcon audio The Falcon has a sophisticated digital processing and audio system centred around a 32 MHz Motorola 56001 Digital Signal Processor or DSP. Separate eight channel (four stereo), 16-bit digital sound record and playback channels which can operate in parallel with each other are provided, making it possible to record eight channel 16-bit stereo data and play back a different four channels of 16-bit stereo data simultaneously using the SoundDMA. All this is independent of any other processor or task. A separate, third party, external DSP device providing the extra ADCs and DACs with the timing crystals for CD 44.1 kHz and DAT 48 kHz sampling rates will be required for full eight track recording and editing. A 16-bit stereo Codec provides a stereo DAC and ADC. The DAC output is directed to the internal loudspeaker (which can be turned off), to the monitor port (for monitors with a built-in speaker) and the stereo headphones jack on the back panel. The DAC attenuation can be controlled for left and right channels independently through operating system calls. The 16-bit stereo ADC is connected to the microphone jack on the back panel and its gain can be controlled by operating system calls. The PSG chip signals can also be fed to the ADC input. All this is linked together with a data path matrix, the DSP send and receive, DMA record and playback, CODEC and input and output external connectors can all be connected in any way so that any receiving device can have its data path connected to any one source device. All data transfers are serial data paths which include a bit clock, data and synchronization signal. There are three possible clock signals, internal 25.175 MHz and 32 MHz and an external clock. The CODEC can only use the internal 25.175 MHz or external clock. The bit clock is taken from the master clock divided by a programmable value of four to 24, in increments of four. The sample rate is the bit rate divided by 128 giving room for eight 16-bit samples per sample period. A sample rate of 49.17 kHz (50 kHz) can be obtained from the 25.175 MHz clock signal and 62.5 kHz from the 32 MHz master clock. However, the CODEC cannot support this sampling rate as it cannot use the 32 MHz clock signal. The 25.175 MHz clock is used to support STE compatible 50 kHz, 25 kHz and 12.5 kHz sound sample rates. The 32 MHz clock can be used to provide an 8 MHz bit rate (1 Mb per second) which is the maximum transfer rate of the DSP external interface. The external clock comes from the DSP connector and third party developers provide the necessary interface box (for instance, AES/EBU SPDIF interfaces which allow direct connection to DAT players and CD mastering recorders) with the crystal necessary to obtain a sampling rate of 44.1 kHz (CD quality) from a 22.5792 MHz signal and 48.0 kHz (DAT quality) from a 24.576 MHz signal. The DMA record and playback channels have a maximum data transfer rate of 1 Mb per second. The DMA input channel provides a fast path to system memory with a 32-byte FIFO on the data path which is synchronized with a memory addressing module which can fill memory in linear, continuous or looping mode. The DMA output channel provides a fast data channel from system memory to subsystem devices also with a 32-byte FIFO which ensures that it can keep up with the real-time response required by certain devices, such as the CODEC DACs. The DSP system has many features which make it ideal for audio processing but the data being processed can also be video, graphics, and any other general purpose data. Some possible applications include tone generation, noise cancellation, pattern recognition, image enhancement, animation, spectral analysis, speech processing, recognition and synthesis, voice mail, acoustic equalizer, digital pre-amplifier and music synthesis. A high-speed software modem is possible with direct connection of the DSP port to the telephone socket. Falcon video There are just too many resolutions to give each resolution a name. In the table below, TV/RGB means any video screen (such as a TV) and analog RGB monitor (such as the Atari SC1224 or even a SM124/5). VGA means any standard VGA monitor. Monitor adapters are necessary that plug into the monitor port to inform the Falcon what kind of monitor is attached. Adapters for 15-pin VGA, Atari SC and SM series monitors, SCART/Peritel cables and for composite video/mixed audio are available. Interlace mode shows the odd numbered lines on one vertical scan, and then the even numbered lines on the following refresh, allowing for persistence of the phosphors to hold the first scan on the screen, thus interlacing or mixing the two to get twice as many lines. However, it takes two screen refreshes to draw one screen, therefore making that frame frequency half of a non-interlaced screen. Unless this frequency is very high in the first place, this causes flickering and uncomfortable viewing. VGA modes are not interlaced. There is a line-doubling mode where 240 lines are used in memory and shown on the screen but each one is displayed twice, doubling up the raster lines to 480 to fill the screen. As each consecutive pair of lines is the same, there is no extra information displayed on the screen as with interlace mode. 640 x 240 is the true resolution in this mode even though 480 raster lines appear on the screen. This mode is a way of halving the memory use of the screen in situations where memory is a constraint. Table F2: Falcon Video Modes From a palette of 262,144 colours: 40 column modes 4 colour normal TV/RGB: 320 x 200 4 colours 2 planes 16 colour normal TV/RGB: 320 x 200 16 colours 4 planes 256 colour normal TV/RGB: 320 x 200 256 colours 8 planes True-colour normal TV/RGB: 320 x 200 true-colour 4 colour interlace TV/RGB: 320 x 400 4 colours 2 planes 16 colour interlace TV/RGB: 320 x 400 16 colours 4 planes 256 colour interlace TV/RGB: 320 x 400 256 colours 8 planes True-colour interlace TV/RGB: 320 x 400 true-colour 4 colour normal VGA: 320 x 480 4 colours 2 planes 16 colour normal VGA: 320 x 480 16 colours 4 planes 256 colour normal VGA: 320 x 480 256 colours 8 planes True-colour normal VGA: 320 x 480 true-colour 4 colour line-doubling VGA: 320 x 240 4 colours 2 planes 16 colour line-doubling VGA: 320 x 240 16 colours 4 planes 256 colour line-doubling VGA: 320 x 240 256 colours 8 planes True-colour line-doubling VGA: 320 x 240 true-colour 80 column modes 2 colour normal TV/RGB: 640 x 200 2 colours 1 plane 4 colour normal TV/RGB: 640 x 200 4 colours 2 planes 16 colour normal TV/RGB: 640 x 200 16 colours 4 planes 256 colour normal TV/RGB: 640 x 200 256 colours 8 planes True-colour normal TV/RGB: 640 x 200 true-colour 4 colour interlace TV/RGB: 640 x 400 4 colours 2 planes 16 colour interlace TV/RGB: 640 x 400 16 colours 4 planes 256 colour interlace TV/RGB: 640 x 400 256 colours 8 planes True-colour interlace TV/RGB: 640 x 400 true-colour 2 colour normal VGA: 640 x 480 2 colours 1 plane 4 colour normal VGA: 640 x 480 4 colours 2 planes 16 colour normal VGA: 640 x 480 16 colours 4 planes 256 colour normal VGA: 640 x 480 256 colours 8 planes 4 colour line-doubling VGA: 640 x 240 4 colours 2 planes 16 colour line-doubling VGA: 640 x 240 16 colours 4 planes 256 colour line-doubling VGA: 640 x 240 256 colours 8 planes ST low, ST medium and ST high resolutions are available on both VGA monitors and analog RGB monitors where on a colour monitor ST high resolution is achieved by using the interlace mode. The ST monochrome monitor (SM124 or SM125) will work with the Falcon030 as well. However, it only supports the ST high resolution mode. All of these modes can be accessed through the GEM VDI. In the case of true- colour mode, there is no colour palette to allow for changing the colour of pixels that have already been drawn. The VDI provides 256 virtual pens for drawing with, which act like the physical pens in other modes except that once the pixel is drawn it cannot be changed using vs_color(). The 1-, 2-, 4- and 8-bit per pixel modes are arranged as they are in a ST, STE or TT. This consists of 16 bits of each plane in adjacent words until all planes are accounted for. The 16-bit per pixel, true-colour mode is organized as packed pixels. Each 16-bit word contains all of the information for a pixel. Since this mode is a true-colour mode, there is no palette to convert the data into RGB information for the video system. The data is encoded in each pixel as RRRRRGGGGGXBBBBB. The least significant 'G' bit ('X' bit) is also used as the overlay bit and should not be used in graphic data. Typically, this bit will be used to select between Falcon and externally generated video on a pixel by pixel basis and is essentially a one bit chroma- key for overlays and video titling. Use of the overlay bit will, of course, drop the number of colours in true-colour mode from 65,536 to 32,768. Most sources argue that true-colour is, in fact, 24-bit colour with over 16 million colours on screen at a time (even though the human eye cannot differentiate the difference between most of them). 65,536 colours is certainly a high colour mode, but not true-colour as experienced on the Apple Mac and other computers. However, it is adequate enough but for the most discerning video and graphics specialist. Overscan is available on all modes on a TV or analog RGB monitor by multiplying the X and Y resolution by 1.2. For example, modes with 320 pixels of horizontal resolution (X resolution) will become 384 pixels across and modes with 640 pixels will become 768 across. Overscanning is done in the X and Y resolution together not independently. On a VGA monitor, overscan is 'faked'. The video hardware doesn't have the capability to do overscan on a VGA monitor. Atari made it so that if an overscan mode is set on a VGA monitor, the normal size screen is seen but the screen is a window on to the bigger overscanned image. This was done for compatibility. A game that has an overscanned start-up picture can use the same picture on both the VGA monitor and the TV or RGB monitor. Overscan cannot be set from the Desktop. The AES and Desktop will work with it but because the parts of the screen cannot be seen Atari thought that that option shouldn't be available from the Desktop. However, overscan can be set using a new XBIOS call Vsetmode(). Software can make new resolution calls whilst running, placing the machine into a new video mode where the AES will be unavailable but the VDI is fully supported. This is primarily for games or paint and animation packages that will run their interface in the current user video mode, but be able to render or output in another, say 768 x 400, true-colour mode. A preview window could be in 16-colour mode with the application doing a wind_update() call and go to the desired final output mode, then back to the user mode releasing wind_update(). Two pins on the monitor port, 18 and 19, are Monitor Select 1 and 0 and are internally pulled high and are read by the operating system to determine the type of monitor connected. TOS then uses this information to set up video timing values suitable for that particular monitor. The values assigned are (where 1 is +5 V and 0 is Ground): M1 M0 Monitor type 0 0 ST Monochrome 0 1 ST Colour 1 0 VGA 1 1 TV Fallback To change to a different mode of operation as a result of a failure of the main mode. False One of two logic conditions represented by a 0-bit and opposite to 'true'. Fan fold A term applied to continuous stationery where the individual sheets are folded successively in opposite directions forming a stack. FAQ Frequently Asked Questions. Commonly used shorthand in e-mail and other messages. Fast Fourier transform - FFT A processing technique for improving the detection and interpretation of signals in the presence of noise. Although a normal computer is capable of performing such a complex task, to achieve acceptable performance in real-time requires the presence of a digital signal processor designed for the job, such as the Falcon030's DSP. Fastload bit Normally, when a program is loaded into the memory of a ST-Falcon all the RAM has to be cleared first to accommodate it, even if it doesn't use it. Rainbow TOS (1.4) introduced the ability to set a program for 'fastload' where a bit in the program file header is set and tells TOS that the program can be loaded without having all of the memory cleared for it. The only memory that is cleared is that required by the program's uninitialized data section (BSS). This feature is most useful on machines with a lot of memory where clearing 4 Mb or more of RAM can take several seconds. That, by itself, is not much but this process can take some considerable time when booting up many programs from the AUTO folder and accessories each one clearing RAM. Also, if programs are being run from other programs (such as in a programming environment, for instance) saving a second on each program makes the computer feel much more responsive. MAKEFAST.PRG by Atari is a program which will set or unset the fastload bit on any program. Fast RAM RAM having an access speed of 80 ns or less, or specifically the 32-bit RAM in the TT also known as TT RAM, Alternative RAM or single purpose RAM. The video chip can only display screen data from ST RAM and so Alternative RAM does not have the video timing constraints of the ST or dual purpose RAM taking up any of the cycles, so it can be made to appear faster to the processor. This RAM uses nybble mode to facilitate burst mode filling of the 68030 caches which means that the CPU fills its cache at one cycle per subsequent access. Fast RAM is available on the TT only through an expansion board with its own MCU. A board contains four SIMM slots allowing 4 Mb or 16 Mb of RAM with 1 Mbit or 4 Mbit chips. A switch on the TT can be selected to place this RAM in burst mode and another set of jumpers can select its start address which is normally $01000000. Any program can run in Fast RAM providing that they do not set the screen base address in Fast RAM or play DMA sound from there, do not try to make a device driver do DMA from or to there (unless the driver knows about the differences between ST RAM and Alternative RAM) and the program must not do DMA itself from or to Fast RAM. Since programs written before the introduction of Alternative RAM are not aware of the rules, the user must inform GEMDOS as to whether a program is eligible to use Alternative RAM or not. A distinction can also be made as to whether the program uses Alternative RAM for its Malloc() calls (memory allocation function), so that a program that allocates a screen buffer can still load into Alternative RAM but its Malloc() calls are satisfied from ST RAM. As of TOS 1.4, one of the reserved long words in the header of executable files acquired a meaning. The least significant bit is the Fastload bit. The next two bits relate to Alternative RAM use. Bit 1, when clear, means that the program must be loaded into ST RAM and bit 2, when clear, means that any Malloc() calls by that program must be satisfied from ST RAM. When these bits are set, then Alternative RAM is used. If there isn't enough Fast RAM to satisfy a request then ST RAM is used. If there isn't enough of that, the request fails. 'Enough' is relative. Some programs have a priority on speed rather than on memory and so 'enough' would be, say, 256 K more than its declared requirements (text + data + BSS). Others need as much memory as possible. A new field in the program's header, called TPAsize, reflects the memory requirements of the program. If the program load bit is clear (load into ST RAM) then this field is ignored. If the program can be loaded into Alternative RAM and there is more of this than ST RAM, the program is loaded into Alternative RAM and this field is ignored. This field is used when Alternative RAM is required and there is more ST RAM available, where its value determines how much Alternative RAM is 'enough'. If there is enough alternative memory, it loads there, if not, then in ST RAM. The value in the TPAsize field increases in 128 K steps and is added to the declared size of the program. The field is four bits wide and is the high four bits of the program flags long word. The amount is the field's value times 128 K, plus 128 K so a value of zero is 128 K. The maximum value is fifteen, meaning 2 Mb. Programs written after the introduction of this program header long word and Alternative RAM can use Mxalloc() instead of Malloc() for getting memory blocks from either ST RAM or alterative RAM. See ST RAM, Malloc, Program header. FAT File Allocation Table. A data structure on a disk representing a map of all the disk's clusters (two sectors) so that the operating system knows where to look for a certain file. Under GEMDOS, each entry is a 12-bit number which points to the next cluster of a file, indicates whether it is the last cluster or whether the cluster is free or unusable. GEMDOS keeps two copies of the FAT on each disk, providing a convenient means of checking the validity of the main one. Father The term applied to the first update version of a file. See Generation. Fault An abnormal hardware or software condition that reduces performance but not necessarily causing a failure. FAX FACSimile (FAXimile). The transmission of data as images over a telephone line and printed out as such at the receiving station. The FAX machine essentially consists of a scanner, a modem and a printer. The original standard, Group 1, was a very slow analogue system which could take up to six minutes to scan a page and send a poor quality image. The Group 2 standard was faster but still using analogue signals. A computer could not manipulate these analogue signals and so the Group 3 standard was established which most FAX machines and FAX modems conform to today. The document is scanned at a resolution of eight pixels per millimetre horizontally and 3.85 pixels/mm vertically giving 203 x 98 dpi. All Group 3 machines must also be able to receive 'Fine' mode transmissions at double the vertical resolution, i.e. 203 x 196 dpi. A minimum data speed of 2,400 bits per second must be supported even though the most common speed is 9,600 bps. If a reliable link is not established the data rate can fall down to as low as 300 bps. The data is compressed to reduce the length of transmission time. FCC Federal Communications Commission. A US organization which allocates frequencies for radio communications. It also tests all electrical and electronic equipment for radio frequency emissions issuing a certificate of compliance to federal rules if they pass. Without this FCC approval, electrical equipment is difficult to sell in the US. The Atari TT's introduction into the US market was greatly delayed by failing FCC tests. FDC Floppy Disk Controller. FDD Flexible Disk Drive or Floppy Disk Drive. Feed To move paper through a printer. Feedback Returning the output of a device to its input to modify or control its operation. Fetch To locate an operand or instruction in main storage and load it into a CPU register for processing. Fetch cycle That part of execution in which a fetch occurs. FF Form Feed. ASCII character 12 used to cause a new form (page) to be displayed on a VDU screen or more usually, to vertically tabulate a printer to the beginning of the first line of the next sheet of paper or eject the sheet from the printer. FFT Fast Fourier Transform. FidoNet The largest bulletin board system network in the world, mainly based on IBM PC compatibles and consisting of around 18,000 nodes. There is a very wide choice of conferences with large amounts of message traffic in most of them and for the most part, access is free. Field In databases, that part of the record that consists of a single piece of information used for processing, i.e. the 'name' field in an address database file. In GEM dialog boxes, it is a single user input line requesting a particular item of data, such as a file name. Also, that part of a display surface to which data can be written and also where a product is sold and used ('a report from the field'). FIFO First In First Out. An algorithm used in determining the order of access of data elements where the next item to be processed is the one that has been waiting the longest. It is the basis of a queue. File In databases, a collection of individual related records, such as an address file. It is now synonymous with any individually accessible unit of related storage, such as a program or data file on a disk. File access The process of reading data from or writing data to a file, making transfers between RAM and backing storage. File attribute An item that identifies a file, such as its name, size or type of access. Also see Attributes. File conversion The process of converting the format of a file to suit another computer or program, e.g. converting a Degas PC3 image file to a GEM IMG image file. File copy To duplicate individual files (as opposed to a disk copy) from one storage medium to another. See Copy. File creation The process of opening a new file, writing data to it and closing it. File description A directory entry identifying a particular file, consisting of its name and size and the date and time of its creation or last update. File directory A list of files on a storage device as maintained by the operating system. On some systems, such as GEMDOS and MS-DOS, directories may contain other directories called subdirectories. Under GEMDOS, a directory is usually called a 'folder'. File menu Usually the second menu in a GEM program where access to the disk input and output operations on the program's data is provided. Items should normally include "New", "Open", the "Load" and "Save" oriented operations, "Import" and "Export", the "Printer" operations and "Quit". File name A character string that uniquely identifies a file within a directory. Under TOS it consists of up to eight alphanumeric characters (not punctuation marks) separated by a full stop from the optional three character extender. File protect The prevention of writing to a file by opening the disk write protect hole or setting the file attributes to read-only. This is used as a safeguard to accidental loss or corruption of data. File selector A GEM routine or a user installed TSR program that enables the user to select files, paths and drives from presented lists when asked to input a file name prior to a file load or save operation. A replacement for the poor built-in TOS file selector is almost a necessity. Martin Patzel's Fselect, Little Green Football's Little Green Selector, Selectric (all shareware) and Universal Item Selector (commercial) are all recommended. Filespec File specifier. The search criterion used in a file selector when displaying files for the user to choose from, e.g. *.DOC only shows files with the .DOC extender. Fill To write a pattern of bits to a memory location, such as to colour an area of screen display in a graphics program. Filter A command or program that takes input from a program, transforms it in some way and then outputs it to the screen or a file. The filter may alter the data in any way, such as to sort it into alphabetical order, to spell check it, to delete every alternate word etc. Filters are often used with pipes and redirection. See Pipes, Redirection. Find A program routine to search for a particular data item. Finger A UNIX command and consequently used across the Internet, which examines the user log on a system for a particular name. It will also tell you if that user is currently logged on. Firmware A term used for programs stored on ROMs, 'firm' being intermediate between 'software' (programs) and 'hardware' (ROM chips). First generation computer A computer utilizing thermionic vacuum tubes or valves, circa 1940s. Fixed disk A magnetic disk that cannot be removed from its housing, such as a Winchester hard disk. Fixed-length record A database record that is of the same length as all other records in that database regardless of the data it contains. Although often a waste of storage space, it enables search operations to be quicker and makes database management simpler. Flag An indicator showing the existence of a certain condition when set and the absence of that condition when clear. Flame In a telecommunications network, an abusive message showing strong disagreement or feelings towards another's message. Flash To blink, a state of cursors. Flatbed plotter A plotter in which the pen moves in two dimensions over the paper. Flat file A non-relational database file representation of a manual card index file. Flat screen display A display screen that is relatively thin in relation to its width and height, and normally refers to non-CRT displays, such as LCD and gas plasma displays. Flexible disk See Floppy. Floating point The representation of numbers that consist of the fractional part or mantissa (the digits) and the exponent (the position of the radix point). The exponent is the power to which the base (normally ten) is raised e.g. 123.4 = 1.234 E2 or 1.234 02 which is equivalent to 1.234 x 10^2. Floating point coprocessor An integrated circuit device designed to perform floating point mathematical calculations at optimum speed and thus relieving the CPU from those tasks. See FPU. FLOPS FLoating point OPerations per Second. A measurement of the speed of operation of a FPU. Floppy disk This refers to the flexible magnetic disk rather than the case that protects it which for a 3.5 inch floppy disk is hard. A floppy disk rotates at 300 rpm and the drive has two read/write heads, one for each surface. The track density is usually 135 tracks per radial inch and the track to track access time is 3 ms on a double density drive. The data transfer rate on the ST is 250 Kbits per second. Early STs had single-sided disk drives which were replaced with double-sided ones in 1985-86 using double density format giving 720 K storage space. High density 1.44 Mb floppy disks were introduced in 1991-92 with the TT, Mega STE and Falcon030. See Disk. Floppy disk controller - FDC The WD1772 chip controlling the floppy disk drive on the ST range or the AJAX chip on the TT and Falcon. It takes the disk access requests from TOS and converts them into the electrical pulses necessary to make the disk drive's heads seek tracks and read and write data. Floppy disk interface The ST-TT range have a port to accept an external floppy disk drive, such as an Atari SF314 or a third party device. See the Connectors Appendix C. Flow The movement of items between two points in a stream or sequence. Flowchart A diagram used to aid program construction showing the movement of control through an algorithm. FM Frequency Modulation. FMail A private message in a bulletin board system network to a specific recipient with a separate file attached for downloading. FMV Full-Motion Video. A term used to describe the ability of a CD-ROM system to store moving pictures rather than just stills. FNet ForemNet. An international bulletin board system network catering specifically for the Atari range of computers and largely replaced by the TurboNet system in 1992 in Europe. It is now mostly confined to the US. Folder The Atari TOS name for a subdirectory containing related files within the main disk directory. It has its own icon which looks like a cardboard manila folder on the Desktop. FOLDRXXX.PRG An official freeware Atari patch program which increases the size of the Operating System pool of memory buffers. It is designed to overcome the infamous 40 folder bug which is especially prevalent in TOS 1.0 and 1.2. Although some effort has been made to lessen the symptoms of this problem, it does still exist in all TOS versions. See Forty folder bug. Folio The original name for the Portfolio, an Atari-badged (almost) IBM PC compatible hand-held computer. Font A particular instance of a typeface in a particular style and size, such as a 12 point Times italic font. In computing this definition tends to be relaxed and can mean any character set of the same general design for display on screen or printer including all its derivatives of style and size, in other words it is confused with 'typeface'. FONTGDOS FONT Graphic Device Operating System. An updated version of GDOS with some extra features such as bézier curve support, font caching and faster printer drivers. It is essentially the same as FSMGDOS but without the font scaling routines, therefore only being capable of handling bitmapped fonts. It requires the EXTEND.SYS file used by FSMGDOS but takes the FSMCACHE value as the value for a miscellaneous cache for itself for internal buffers and data structures (using all of it towards the cache as opposed to just a percentage). The second FSMCACHE value is ignored. The printer drivers are faster than the older GDOS ones. The FONTGDOS.PRG file must be placed in the AUTO folder as with the GDOS set up and the ASSIGN.SYS and EXTEND.SYS files placed in the root directory. Three accessories which also come in CPX module form are also supplied which help construct the ASSIGN.SYS and EXTEND.SYS files. FONTGDOS.ACC allows the ASSIGN.SYS file to be altered, selecting the bitmapped fonts, drivers and print quality. FSM.ACC allows the cache sizes in EXTEND.SYS to be changed, and FSMPRINT.ACC is used to change the parameters of the printer, such as paper size, quality and colours. FONTGDOS was issued almost as an apology for the continued delays with FSMGDOS in early 1992. To the programmer and user, it is essentially to be used the same as GDOS 1.1 except for the bézier curve features and the advantages of the caches. Tests have shown it to be better behaved and faster than GDOS 1.1 and compatible with GDOS software. See FSMGDOS, GDOS, SpeedoGDOS, ASSIGN.SYS, EXTEND.SYS, Outline fonts. Foreground A program in a multiprogramming environment that takes priority over other programs. ForemNet See FNet. Form To a programmer, a graphic object containing one or more other objects, such as text, boxes, buttons, images and icons, for instance a GEM dialog box. Some forms are very sophisticated, such as the whole Desktop in NeoDesk. Formal parameter A value entered in a program to establish the type, size or structure of an item of data that will be inserted during compilation or at run time. Format The initialization of a disk ready for use, physically removing all previous data. The process consists of checking each track for defects and writing identifying and control data to each track and sector for access purposes. The correct term for such a procedure is 'initialize', where formatting was only one part of it. In micros, at least, the term formatting has taken over to mean all the operations of disk initialization. A ST double density disk formatted to the normal Desktop standard has 80 concentric tracks with track 0 on the outside and track 79 nearest the centre. Each track is divided into nine sectors, numbered 1 to 9. On a single-sided disk the tracks and sectors are arranged as follows: Track 0, Sector 1 Boot Sector Track 0, Sector 2-6 FAT 1 Track 0, Sector 7-Track 1, Sector 2 FAT 2 Track 1, Sector 3-9 Directory Track 2-Track 79 File data A double-sided disk has 80 tracks with nine sectors per track on each side of the disk and is arranged as follows: Side A, Track 0, Sector 1 Boot Sector Side A, Track 0, Sector 2-6 FAT 1 Side A, Track 0, Sector 7-9 and Side B, Track 0, Sector 1-2 FAT 2 Side B, Track 0, Sector 3-9 Directory Side A and B, Track 1-Track 79 File data Each sector holds a maximum of 512 bytes of data and sectors are arranged in clusters which are the smallest storage units, which is two sectors. Only one file may be allocated a cluster, so that if a file does not fill the whole 1,024 bytes of a cluster, the excess remains empty and unusable. For instance, ten Degas fill pattern files, normally 64 bytes each, would occupy 10,240 bytes on a disk rather than 640 bytes! Larger files are obviously stored more efficiently but the last cluster of any file will always be partly empty and unused. Nonstandard disk formats are common on the ST, where an increase in the number of tracks or sectors per track is achieved. Using ten sectors per track is generally safe and portable between computers, going beyond that (fourteen has been tried) is generally not recommended because the quality of disk drives and disks varies so much. The same applies to sectors. Up to 86 sectors per track has been tried but generally a mechanical stop in the drive unit itself normally prevents the read/write heads from going too far towards the centre of the disk. Using software to move the head too far inwards will result in rather unpleasant noises coming from the disk drive and can force the heads out of alignment. Again, one or two extra sectors may be acceptable, any more is definitely not recommended. A high density floppy disk has twice the number of sectors per track as a double density disk. In order to achieve this, the FDC clock signal needs to be twice the normal rate, at 16 MHz. At the time of format the disk can be given a volume name which has the same form as a file name and stored on the disk. This can help to identify a disk's contents. Also, the term is used to describe the physical organization of data within a file or on screen, such as arranging the text layout to conform to left and right margin settings and justification. See Boot Sector, Cluster, Directory sectors, FAT, Interleave, Sectors, Tracks. Formatter An operating system routine or utility program that enables the formatting of disks usually with options to extend the disk's 'normal' capacity and/or access speed. Form Feed See FF. FORTH A high-level language designed for real-time control applications. FORTRAN FORmula TRANslation. The first high-level language designed for mathematical and scientific applications by IBM and released in 1957. Forty folder bug TOS allows for 80 blocks of RAM buffer in its system 'OS Pool'. Whenever a folder is 'active' TOS creates and uses two of these blocks to store its directory structure contents. An active folder is one which is the root directory of the device it's on, or which has open files, or which is the current directory of one or more processes for that drive, or which has an 'active' subdirectory. Each process has a current directory on every logical drive. In addition, one block is used per open file and one quarter block is used per memory chunk (allocated or free) in the system TPA. When files are closed, processes terminated, or memory chunks are freed these blocks are given back to the OS pool. However, for TOS 1.0 and 1.2 'active' meant 'seen'. Getting a list of the files in a directory causes all the folders there to take up blocks of the OS pool regardless of whether they are opened or not. In addition, blocks never get freed in the pool. Also, once blocks have been used for managing TPA memory chunks, they were unavailable for managing folders, and vice versa. Eventually - and quickly with a hard disk - the OS pool runs out and unpredictable and serious problems can occur which normally ends with out of memory errors and a system crash. TOS 1.4 lifts these restrictions and so fixes this particular 40 folder bug. There are still limits, the 80 block OS pool can still run out but this is unlikely except under extreme circumstances of having an inordinate number and depth of folders and open files. The Atari FOLDRXXX program was released to add memory to the OS pool. Naming it FOLDR100.PRG and placing it in the AUTO folder gives the OS pool another 200 blocks, room for 100 additional active folders. This can still be used with TOS 1.4 and later if a user does have deeply structured directories and gets the "Out of Internal Memory" error. Closely associated with this 40 folder problem are the bugs in the GEMDOS Malloc() function which is used to allocate memory blocks to a program. The version of Malloc() in TOS 1.0 and 1.2 had a limit of 20 allocated blocks per process and attempting to allocate more would crash the system. Again, FOLDRXXX would help alleviate this problem as Malloc() uses the OS pool. However, another bug was introduced in TOS 1.4. Many programmers have been relying on the fact that Malloc() in TOS 1.0 and 1.2 used to allocate two blocks of memory contiguously in memory. As so many programs relied on this, the new Malloc() function had to accommodate this behaviour. The bug was introduced into the routine that coalesces contiguous memory blocks into one free memory block. A patch program called POOLFIX.PRG is used to frequently coalesce free memory blocks so that the bugged routine never executes. Unfortunately, POOLFIX and POOLFIX2 are bugged and should not be used. POOLFIX3 is the official Atari patch program which should be run from the AUTO folder. POOLFIX4 was introduced by Claus Brod in Germany to fix a problem POOLFIX3 had with some hard disks. On systems that install a cookie jar, the _OOL Cookie shows that the POOLFIX TOS patch program is installed. Forward channel A message channel, a communications channel used to carry data in an asymmetric duplex system. Fount See Font. FPATCH2.PRG An official freeware Atari patch program that fixes two problems in the Falcon BIOS in TOS 4.00-4.04. Sound is not initialized properly and the Bconmap() function doesn't work. This patch supersedes FPATCH1.PRG which worked by hooking into the BIOS trap and intercepting all the Bconxxx() function calls. Version 2 fixes the Bconmap() problem directly by setting the Bconmap() table size to its correct value and hence requires no resident code. It also has the benefit of allowing the Falcon LAN port to be accessed via the BIOS. It should be run from the AUTO folder. FPU Floating Point processor Unit. An integrated circuit device designed to perform floating point mathematical calculations at optimum speed and relieving the CPU from those tasks. This chip is often a coprocessor to the main CPU but in the latest CPU's, such as the MC68040 and the Intel 80486, the coprocessor is integrated into the main chip architecture. However, the processor, as with any FPU, will only speed up the mathematical operations of programs that are specifically written to use it, of which there are very few on the ST-Falcon even though most C compilers have floating point routine libraries. The Mega ST and Mega STE can both support MC68881 FPUs and the TT and Falcon030 support a MC68882 FPU in coprocessor mode. See SFP004, MC68881, MC88882. Fragmentation The state of a disk when files do not occupy contiguous sectors on its surface. When files are deleted from a disk their sectors become available to other files which may need more than these sectors for storage. The other sectors are found elsewhere on the disk making them non-contiguous across the disk surface. With increasing deletion and copying this fragmentation of the newer files gets worse. Consequently, it takes longer for the disk's read/write heads to read the data from all these scattered tracks and it takes longer to find empty sectors to write data to, thus making all disk operations slower. Some programs can defragment a disk but because of the way they work, a disk backup is always recommended beforehand. A full disk backup, zeroing the disks and copying the files back again will defragment a disk. Frame A term used to describe the 'box' within which text or graphic images are placed in WIMP environment DTP and graphic processing programs. Such frames are usually moveable and re-sizable by use of handles and if so, are often called rubber boxes. Frame rate The refresh rate. Framing Using beginning and ending delimiters around data items to distinguish one item from another, especially in a stream of such items. Framing bits Start and stop bits. Free space The available memory on disk or RAM for use. Free standing A functional unit contained within its own case and not enclosed within the main system. Also, an intelligent terminal in a network. Freeware Programs that are freely available and generally distributed by PD libraries and bulletin board networks but to which the programmer keeps all rights. The usage fee may be free or voluntary, the user being under no obligation to pay as with shareware. Freeware programs are not public domain, the copyright is still retained by the programmer and they cannot be sold for profit. See Public domain, Shareware. Frequency The number of times per second that a sequence of conditions is repeated, such as waves of sound or current. The unit of measurement is a Hertz (Hz). Frequency modulation In communications and a system using a carrier wave, the method of modulation in which the frequency of the carrier wave is changed in an analogue manner to transmit speech or data. Also, a method of data recording onto magnetizable surfaces in which the direction of current in the coil of the read/write head (and hence the direction of orientation of the magnetizable articles) is changed at intervals established by a clock sequence. The direction is changed at the midpoint of an interval to write a 1-bit and left unchanged for a 0- bit. Frequency-shift keying A method of data transmission in which a carrier wave is modulated at only a limited number of frequencies, each of which represents a bit or an established group of bits, such as a dibit. It is normally used for low-speed transmissions, such as 300 bps. Friction feed A printer that does not use sprockets to move the paper but relies on the friction of the platen against the paper to move it. Front end The user input/output interface program between the user and the operating system, such as the GEM Desktop and the MS-DOS command line. FSFMV Full-Screen, Full-Motion Video. A term used to describe the attributes of some CD-ROM systems which can display a moving picture the same size as the display device being used. FSMGDOS Font Scaling Module Graphic Device Operating System. A replacement for GDOS allowing use of scalable outline fonts as well as GDOS bitmapped ones. FSMGDOS generates character bitmaps of any point size for devices of any resolution with independent height and width settings for compressed and expanded font styles. Output can be mirrored on the X and Y axis as well as rotated and skewed. Font caching for bitmapped fonts is an important feature enabling only the fonts currently in use to be loaded into memory. As long as the memory size of the BITCACHE, which can be specified by the user, is larger than the biggest font, FSMGDOS will be able to use as many bitmap fonts as the user wishes in a limited memory space. Another cache for the scalable outline fonts is also provided. This cache, FSMCACHE, holds the actual character data when a character is requested and FSMGDOS builds the bitmap from the font data. This first generation of any character will be slow so the bitmap is retained in memory for later use so that each character doesn't have to be generated every time. These caches can be saved to disk. A third cache (second FSMCACHE parameter) is used for internal buffers and data structures and its size depends on how many fonts are used and their point sizes. Support for bézier curves and pair or track kerning control is present. FSMGDOS should be compatible with all programs using GDOS. An install program should make installation of FSMGDOS easy and three accessories are provided (also in CPX module format) to alter this configuration. FSM Font Manager allows the configuration of the fonts, which ones to use and their sizes. It also allows manipulation of the FSM caches and creation of width tables. The FSM Printer Configuration accessory is used to change the printer driver configuration including the page size, quality and number of colours. The last accessory, GDOS Printer Selector, is used to manage the old bitmaps fonts and effectively manipulates the ASSIGN.SYS file. Although developer's versions abound with regular updates, consistent problems have caused great delays with promises of its appearance for several years. FSMGDOS was to be available at the end of 1992 but was replaced by SpeedoGDOS using the scaling technology of the Bitstream Speedo Font Scaler. See GDOS, FONTGDOS, SpeedoGDOS, ASSIGN.SYS, EXTEND.SYS, Outline font. FTP File Transfer Protocol. A protocol for transferring files under TCP/IP across the Internet. Also, the name of the program itself, usually UNIX-based. Fuji The Atari icon formed by Atari characters 14 and 15, being a representation of Mount Fuji in Japan and the company's trademark. Full box The icon in the top right-hand corner of a GEM window which, when clicked on, will open the window to the maximum size of the screen and when clicked on again, back to the previous size. It is sometimes referred to as the Zoom box. Fulling The act of clicking on the Full box and making the GEM window take on the size of the whole screen. Function That which is done or performed. Also, a sequence of instructions provided to accomplish a particular operation and providing a single result or output for any input arguments and is invoked by making a call to its name supplying the arguments. Sometimes called a routine. Also, an expression. Function key A special key on a keyboard [F1]-[F10] assigned a program independent operation. Although there is a de facto standard for their use on the PC compatibles, i.e. [F1] provides Help, there is no such standard on the ST- Falcon range. NewDesk allows them to be used to launch programs. Functional unit An item of hardware which performs some function within a computer system, such as a modem, printer, disk drive or the computer itself. FUNNEL An Atari ASIC chip for the TT. ST RAM on the TT is 64 bits wide and as the 68030 has only a 32-bit width, the FUNNEL interleaves the 64 bits down to 32 bits for the 68030 and the sixteen bits required for the sound and elsewhere. See ST RAM. Fuse A current-limiting device that protects a circuit from excessive current flow by melting, thus breaking a circuit and stopping that current. FWIW For What It's Worth. Commonly used shorthand in e-mail and other messages. FYI For Your Information. Commonly used shorthand in e-mail and other messages. F 115 entries EOF