diff --git a/appendixC.txt b/appendixC.txt index dc72384..1e5859f 100644 --- a/appendixC.txt +++ b/appendixC.txt @@ -1,636 +1,451 @@ -.ec] -.bp -.np -.ce -APPENDIX C - GLOSSARY -.sp1 -.pn5 -.in20 -.pi-20 +# APPENDIX C - GLOSSARY -ACCESS TIME]>The time required to -locate and read or write data on a -direct access storage device, such as -a diskette drive. +ACCESS TIME +The time required to locate and read or write data on a direct access storage +device, such as a diskette drive. -ADDRESS]>The numeric location of a -piece of data in memory. Usually -given as a hexadecimal number from -$0000 to $FFFF (65535 decimal). A -disk address is the location of a -data sector, expressed in terms of its -track and sector numbers. +ADDRESS +The numeric location of a piece of data in memory. Usually given as a +hexadecimal number from $0000 to $FFFF (65535 decimal). A disk address is the +location of a data sector, expressed in terms of its track and sector numbers. -ALGORITHM]>A sequence of steps which -may be performed by a program or -other process, which will produce a -given result. +ALGORITHM +A sequence of steps which may be performed by a program or other process, which +will produce a given result. -ALPHANUMERIC]>An alphabetic character -(A-Z) or a numeric digit (0-9). The -term used to refer to the class of all -characters and digits. +ALPHANUMERIC +An alphabetic character (A-Z) or a numeric digit (0-9). The term used to refer +to the class of all characters and digits. -ANALOG]>As opposed to digital. -Having a value which is continuous, -such as a voltage or electrical -resistance. +ANALOG +As opposed to digital. Having a value which is continuous, such as a voltage or +electrical resistance. -AND]>The logical process of -determining whether two bits are both -ones. 0 AND 1 results in 0 (false), -1 AND 1 results in 1 (true). +AND +The logical process of determining whether two bits are both ones. 0 AND 1 +results in 0 (false), 1 AND 1 results in 1 (true). -ARM]>The portion of a disk drive -which suspends the read/write head -over the disk's surface. The arm can -be moved radially to allow access to -different tracks. +ARM +The portion of a disk drive which suspends the read/write head over the disk's +surface. The arm can be moved radially to allow access to different tracks. -ASCII]>American Standard Code for -Information Interchange. A -hexadecimal to character conversion -code assignment, such that the 256 -possible values of a single byte may -each represent a alphabetic, numeric, -special, or control character. ASCII -is used when interfacing to -peripherals, such as keyboards, -printers, or video text displays. +ASCII +American Standard Code for Information Interchange. A hexadecimal to character +conversion code assignment, such that the 256 possible values of a single byte +may each represent a alphabetic, numeric, special, or control character. ASCII +is used when interfacing to peripherals, such as keyboards, printers, or video +text displays. -ASSEMBLY LANGUAGE]>Also known as -MACHINE LANGUAGE. The native -programming language of the -individual computer. Assembly -language is oriented to the machine, -and is not humanized, as is BASIC, -PASCAL, or FORTRAN. An assembler is -used to convert assembly language -statements to an executable program. +ASSEMBLY LANGUAGE +Also known as MACHINE LANGUAGE. The native programming language of the +individual computer. Assembly language is oriented to the machine, and is not +humanized, as is BASIC, PASCAL, or FORTRAN. An assembler is used to convert +assembly language statements to an executable program. -BACKUP]>The process of making a copy -of a program or data against the -possibility of its accidental loss or -destruction. +BACKUP +The process of making a copy of a program or data against the possibility of its +accidental loss or destruction. -BASE]>The number system in use. -Decimal is base 10, since each digit -represents a power of 10 -(1,10,100,...). Hexadecimal is base -16 (1,16,256,...). Binary is base 2 -(1,2,4,8,...). +BASE +The number system in use. Decimal is base 10, since each digit represents a +power of 10 (1,10,100,...). Hexadecimal is base 16 (1,16,256,...). Binary is +base 2 (1,2,4,8,...). -BINARY]>A number system based upon -powers of 2. Only the digits 0 and 1 -are used. 101 in binary, for -example, is 1 units digit, 0 twos, -and 1 fours, or 5 in decimal. +BINARY +A number system based upon powers of 2. Only the digits 0 and 1 are used. 101 +in binary, for example, is 1 units digit, 0 twos, and 1 fours, or 5 in decimal. -BIT]>A single binary digit (a 1 or a -0). A bit is the smallest unit of -storage or information in a computer. +BIT +A single binary digit (a 1 or a 0). A bit is the smallest unit of storage or +information in a computer. -BIT CELL]>The space on a diskette, -between two clock pulses, which can -hold the value of a single binary 0 -or 1 (bit). +BIT CELL +The space on a diskette, between two clock pulses, which can hold the value of a +single binary 0 or 1 (bit). -BIT SLIP MARKS]>The epilogue of a -disk field. Used to double check -that the disk head is still in read -sync and the sector has not been -damaged. +BIT SLIP MARKS +The epilogue of a disk field. Used to double check that the disk head is still +in read sync and the sector has not been damaged. -BOOT/BOOTSTRAP]>The process of -loading a very large program into -memory by loading successively larger -pieces, each of which loads its -successor. The program loads itself -by "pulling itself up by its -bootstraps". +BOOT/BOOTSTRAP +The process of loading a very large program into memory by loading successively +larger pieces, each of which loads its successor. The program loads itself by +"pulling itself up by its bootstraps". -BRK]>BREAK. An assembly langauge instruction -which can be used to force an -interrupt and immediate suspension of -execution of a program. +BRK +BREAK. An assembly langauge instruction which can be used to force an interrupt +and immediate suspension of execution of a program. -BUFFER]>An area of memory used to -temporarily hold data as it is being -transferred to or from a peripheral, -such as a disk drive. +BUFFER +An area of memory used to temporarily hold data as it is being transferred to or +from a peripheral, such as a disk drive. -BUG]>A programming error. Faulty -operation of a program. +BUG +A programming error. Faulty operation of a program. -BYTE]>The smallest unit of -addressable memory in a computer. A -byte usually consists of 8 bits and -can contain a decimal number ranging -from 0 to 255 or a single +BYTE +The smallest unit of addressable memory in a computer. A byte usually consists +of 8 bits and can contain a decimal number ranging from 0 to 255 or a single alphanumeric character. -CARRIAGE RETURN]>A control character -which instructs the printer to end -one line and begin another. When -printing a carriage return is usually -followed by a line feed. +CARRIAGE RETURN +A control character which instructs the printer to end one line and begin +another. When printing a carriage return is usually followed by a line feed. -CARRY FLAG]>A 6502 processor flag -which indicates that a previous -addition resulted in a carry. Also -used -as an error indicator by many system -programs. +CARRY FLAG +A 6502 processor flag which indicates that a previous addition resulted in a +carry. Also used as an error indicator by many system programs. -CATALOG]>A directory of the files on -a diskette. See DIRECTORY. +CATALOG +A directory of the files on a diskette. See DIRECTORY. -CHAIN]>A linked list of data -elements. Data is chained if its -elements need not be contiguous in -storage and -each element can be found from its -predecessor via an address pointer. +CHAIN +A linked list of data elements. Data is chained if its elements need not be +contiguous in storage and each element can be found from its predecessor via an +address pointer. -CHECKSUM/CRC]>A method for verifying -that data has not been damaged. When -data is written, the sum of all its -constituent bytes is stored with it. -If, when the data is later read, its -sum no longer matches the checksum, -it has been damaged. +CHECKSUM/CRC +A method for verifying that data has not been damaged. When data is written, +the sum of all its constituent bytes is stored with it. If, when the data is +later read, its sum no longer matches the checksum, it has been damaged. -CLOBBERED]>Damaged or destroyed. A -clobbered sector is one which has -been overwritten such that it is -unrecoverable. +CLOBBERED +Damaged or destroyed. A clobbered sector is one which has been overwritten such +that it is unrecoverable. -CODE]>Executable instructions to the -computer, usually in machine -language. +CODE +Executable instructions to the computer, usually in machine language. -COLDSTART]>A restart of a program -which reinitializes all of its -parameters, usually erasing any work -which was in progress at the time of -the restart. A DOS coldstart erases -the BASIC program in memory. +COLDSTART +A restart of a program which reinitializes all of its parameters, usually +erasing any work which was in progress at the time of the restart. A DOS +coldstart erases the BASIC program in memory. -CONTIGUOUS]>Physically next to. Two -bytes are contiguous if they are -adjoining each other in memory or on -the disk. +CONTIGUOUS +Physically next to. Two bytes are contiguous if they are adjoining each other +in memory or on the disk. -CONTROL BLOCK]>A collection of data -which is used by the operating system -to manage resources. Examples of a -control block used by DOS are the -file buffers. +CONTROL BLOCK +A collection of data which is used by the operating system to manage resources. +Examples of a control block used by DOS are the file buffers. -CONTROL CHARACTER]>A special ASCII -code which is used to perform a -unique function on a peripheral, but -does not generate a printable -character. -Carriage return, line feed, form -feed, and bell are all control -characters. +CONTROL CHARACTER +A special ASCII code which is used to perform a unique function on a peripheral, +but does not generate a printable character. Carriage return, line feed, form +feed, and bell are all control characters. -CONTROLLER CARD]>A hardware circuit -board which is plugged into an APPLE -connector which allows communication -with a peripheral device, such as a -disk or printer. A controller card -usually contains a small driver -program in ROM. +CONTROLLER CARD +A hardware circuit board which is plugged into an APPLE connector which allows +communication with a peripheral device, such as a disk or printer. A controller +card usually contains a small driver program in ROM. -CSWL]>A vector in zero-page through -which output data is passed for -display on the CRT or for printing. +CSWL +A vector in zero-page through which output data is passed for display on the CRT +or for printing. -CYCLE]>The smallest unit of time -within the central processor of the -computer. Each machine language -instruction requires two or more -cycles to complete. One cycle (on -the APPLE) is one micro-second or one -millionth of a second. +CYCLE +The smallest unit of time within the central processor of the computer. Each +machine language instruction requires two or more cycles to complete. One cycle +(on the APPLE) is one micro-second or one millionth of a second. -DATA]>Units of information. +DATA +Units of information. -DATA SECTOR BUFFER]>On the APPLE, a -256 byte buffer used by DOS to hold -the image of any given sector on the -diskette. As information is read -from the file, data is extracted from -the data sector buffer until it is -exhausted, at which time it is -refilled with the next sector image. +DATA SECTOR BUFFER +On the APPLE, a 256 byte buffer used by DOS to hold the image of any given +sector on the diskette. As information is read from the file, data is extracted +from the data sector buffer until it is exhausted, at which time it is refilled +with the next sector image. -DATA TYPE]>The type of information -stored in a byte. A byte might -contain a printable ASCII character, binary -numeric data, or a machine language -instruction. +DATA TYPE +The type of information stored in a byte. A byte might contain a printable +ASCII character, binary numeric data, or a machine language instruction. -DCT]>Device Characteristics Table. -Used as an input parameter table to -Read/Write Track/Sector (RWTS) to -describe the hardware characteristics -of the diskette drive. +DCT +Device Characteristics Table. Used as an input parameter table to Read/Write +Track/Sector (RWTS) to describe the hardware characteristics of the diskette +drive. -DECIMAL]>A number system based upon -powers of 10. Digits range from 0 to -9. +DECIMAL +A number system based upon powers of 10. Digits range from 0 to 9. -DEFERRED COMMANDS]>DOS commands which -may (or must) be invoked from within -an executing BASIC program. OPEN, -READ, WRITE, and CLOSE are all -examples of deferred commands. +DEFERRED COMMANDS +DOS commands which may (or must) be invoked from within an executing BASIC +program. OPEN, READ, WRITE, and CLOSE are all examples of deferred commands. -DIGITAL]>As opposed to analog. -Discrete values as opposed to -continuous ones. Only digital values -may be stored in a computer. Analog -measurements from the real world, -such as a voltage or the level of -light outside, must be converted into -a numerical value which, of -necessity, must be "rounded off" to a -discrete value. +DIGITAL +As opposed to analog. Discrete values as opposed to continuous ones. Only +digital values may be stored in a computer. Analog measurements from the real +world, such as a voltage or the level of light outside, must be converted into a +numerical value which, of necessity, must be "rounded off" to a discrete value. -DIRECT ACCESS]>Peripheral storage -allowing rapid access of any piece of -data, regardless of its placement on -the medium. Magnetic tape is -generally not considered direct -access, since the entire tape must be -read to locate the last byte. A -diskette is direct access, since the -arm may be rapidly moved to any -track and sector. +DIRECT ACCESS +Peripheral storage allowing rapid access of any piece of data, regardless of its +placement on the medium. Magnetic tape is generally not considered direct +access, since the entire tape must be read to locate the last byte. A diskette +is direct access, since the arm may be rapidly moved to any track and sector. -DIRECTORY]>A catalog of all files -stored on a diskette. The directory -must contain each file's name and its -location on the disk as well as other -information regarding the type of -data stored there. +DIRECTORY +A catalog of all files stored on a diskette. The directory must contain each +file's name and its location on the disk as well as other information regarding +the type of data stored there. -DISK INITIALIZATION]>The process -which places track formatting -information, including sectors and -gaps, on a blank diskette. -During disk initialization, DOS also -places a VTOC and directory on the -newly formatted disk, as well as -saving the HELLO program. +DISK INITIALIZATION +The process which places track formatting information, including sectors and +gaps, on a blank diskette. During disk initialization, DOS also places a VTOC +and directory on the newly formatted disk, as well as saving the HELLO program. -DISPLACEMENT]>The distance from the -beginning of a block of data to a -particular byte or field. -Displacements are usually given -beginning with 0, for the first byte, -1 for the second, etc. Also known as -an offset. +DISPLACEMENT +The distance from the beginning of a block of data to a particular byte or +field. Displacements are usually given beginning with 0, for the first byte, 1 +for the second, etc. Also known as an offset. -DRIVER]>A program which provides an -input stream to another program or an -output device. A printer driver -accepts input from a user program in -the form of lines to be printed, and -sends them to the printer. +DRIVER +A program which provides an input stream to another program or an output device. +A printer driver accepts input from a user program in the form of lines to be +printed, and sends them to the printer. -DUMP]>An unformatted or partially -formatted listing of the contents of -memory or a diskette in hexadecimal. -Used for diagnostic purposes. +DUMP +An unformatted or partially formatted listing of the contents of memory or a +diskette in hexadecimal. Used for diagnostic purposes. -ENCODE]>To translate data from one -form to another for any of a number -of reasons. In DOS 3.3, -Data is encoded from 8 -bit bytes to 6 bit bytes for storage -on a DISK II. +ENCODE +To translate data from one form to another for any of a number of reasons. In +DOS 3.3, Data is encoded from 8 bit bytes to 6 bit bytes for storage on a DISK +II. -ENTRY POINT (EPA)]>The entry point -address is the location within a -program where execution is to start. -This is not necessarily the same as -the load point (or lowest memory +ENTRY POINT (EPA) +The entry point address is the location within a program where execution is to +start. This is not necessarily the same as the load point (or lowest memory address in the program). -EOF]>End Of File. This mark signals -the end of a data file. $00 for -APPLE DOS text files. +EOF +End Of File. This mark signals the end of a data file. $00 for APPLE DOS text +files. -EPILOGUE]>The last three bytes of a -field on a track. These unique bytes -are used to insure the integrity of -the data which preceeds them. +EPILOGUE +The last three bytes of a field on a track. These unique bytes are used to +insure the integrity of the data which preceeds them. -EXCLUSIVE OR]>A logical operation -which compares two bits to determine -if they are different. 1 EOR 0 -results in 1. 1 EOR 1 results in 0. +EXCLUSIVE OR +A logical operation which compares two bits to determine if they are different. +1 EOR 0 results in 1. 1 EOR 1 results in 0. -FIELD]>A group of contiguous bytes -forming a single piece of data, such -as a person's name, his age, or his -social security number. In disk -formatting, a group of data bytes -surrounded by gaps. +FIELD +A group of contiguous bytes forming a single piece of data, such as a person's +name, his age, or his social security number. In disk formatting, a group of +data bytes surrounded by gaps. -FILE]>A named collection of data on a -diskette or other mass storage -medium. Files can contain data or -programs. +FILE +A named collection of data on a diskette or other mass storage medium. Files +can contain data or programs. -FILE BUFFERS]>In APPLE DOS, a -collection of buffers used to manage -one open file. Included are a data -sector buffer, a Track/Sector List -sector buffer, a file manager -workarea buffer, the name of the -file, and pointers. The DOS command, -MAXFILES 3, causes 3 of these file -buffers to be allocated. +FILE BUFFERS +In APPLE DOS, a collection of buffers used to manage one open file. Included +are a data sector buffer, a Track/Sector List sector buffer, a file manager +workarea buffer, the name of the file, and pointers. The DOS command, MAXFILES +3, causes 3 of these file buffers to be allocated. -FILE DESCRIPTOR]>A single entry in a -diskette directory which describes -one file. Included are the name of -the file, its data type, its length, -and its location on the diskette. +FILE DESCRIPTOR +A single entry in a diskette directory which describes one file. Included are +the name of the file, its data type, its length, and its location on the +diskette. -FILE MANAGER]>That portion of DOS -which manages files. The file -manager handles such general -operations as OPEN, CLOSE, READ, -WRITE, POSITION, RENAME, DELETE, etc. +FILE MANAGER +That portion of DOS which manages files. The file manager handles such general +operations as OPEN, CLOSE, READ, WRITE, POSITION, RENAME, DELETE, etc. -FILE TYPE]>The type of data held by a -file. Valid DOS file types are -Binary, Applesoft, Integer-BASIC, -Text, Relocatable, S, A, and B. +FILE TYPE +The type of data held by a file. Valid DOS file types are Binary, Applesoft, +Integer-BASIC, Text, Relocatable, S, A, and B. -FIRMWARE]>A middle ground between -hardware and software. Usually used -to describe micro-code or programs -which have been stored in read-only -memory. +FIRMWARE +A middle ground between hardware and software. Usually used to describe +micro-code or programs which have been stored in read-only memory. -GAPS]>The spaces between fields of -data on a diskette. Gaps on an APPLE -diskette contain self-sync bytes. +GAPS +The spaces between fields of data on a diskette. Gaps on an APPLE diskette +contain self-sync bytes. -HARD ERROR]>An unrecoverable -Input/Output error. The data stored -in the disk sector can never be -successfully read again. +HARD ERROR +An unrecoverable Input/Output error. The data stored in the disk sector can +never be successfully read again. -HARDWARE]>Physical computer -equipment, as opposed to programs -which run on the equipment. -A disk drive is an example of a -hardware component. +HARDWARE +Physical computer equipment, as opposed to programs which run on the equipment. +A disk drive is an example of a hardware component. -HEAD]>The read/write head on a -diskette drive. A magnetic pickup, -similar in nature to the head on a -stereo tapedeck, which rests on the -spinning surface of the diskette. +HEAD +The read/write head on a diskette drive. A magnetic pickup, similar in nature +to the head on a stereo tapedeck, which rests on the spinning surface of the +diskette. -HEXADECIMAL/HEX]>A numeric system -based on powers of 16. Valid hex -digits range from 0 to 9 and A to F, -where A is 10, B is 11, ... , and F -is 15. B30 is 11 256's, 3 16's, and -0 1's, or 2864 in decimal. -Two hexadecimal digits can be used to -represent the contents of one byte. -Hexadecimal is used with computers -because it easily converts with -binary. +HEXADECIMAL/HEX +A numeric system based on powers of 16. Valid hex digits range from 0 to 9 and +A to F, where A is 10, B is 11, ... , and F is 15. B30 is 11 256's, 3 16's, and +0 1's, or 2864 in decimal. Two hexadecimal digits can be used to represent the +contents of one byte. Hexadecimal is used with computers because it easily +converts with binary. -HIGH MEMORY]>Those memory locations -which have high address values. -$FFFF is the highest memory location. -Also called the "top" of memory. +HIGH MEMORY +Those memory locations which have high address values. $FFFF is the highest +memory location. Also called the "top" of memory. -HIMEM]>APPLE's zero-page address -which identifies the first byte past -the available memory which can be -used to store BASIC programs and -their variables. +HIMEM +APPLE's zero-page address which identifies the first byte past the available +memory which can be used to store BASIC programs and their variables. -IMMEDIATE COMMAND]>A DOS command -which may be entered at any time, -especially when DOS is waiting for a -command from the keyboard. Deferred -commands are the opposite of +IMMEDIATE COMMAND +A DOS command which may be entered at any time, especially when DOS is waiting +for a command from the keyboard. Deferred commands are the opposite of immediate commands. -INDEX]>A displacement into a table or -block of storage. +INDEX +A displacement into a table or block of storage. -INSTRUCTION]>A single step to be -performed in an assembly language or -machine language program. -Instructions perform such operations -as addition, subtraction, store, or -load. +INSTRUCTION +A single step to be performed in an assembly language or machine language +program. Instructions perform such operations as addition, subtraction, store, +or load. -INTEGER]>As opposed to floating -point. A "whole" number with no -fraction associated with it. +INTEGER +As opposed to floating point. A "whole" number with no fraction associated with +it. -INTERCEPT]>A program which logically -places itself in the execution path -of another program, or pair of -programs. A video intercept -is used to re-direct program output -from the screen to a printer, -for example. +INTERCEPT +A program which logically places itself in the execution path of another +program, or pair of programs. A video intercept is used to re-direct program +output from the screen to a printer, for example. -INTERLEAVE]>The practice of selecting -the order of sectors on a diskette -track to minimize access time due to -rotational delay. Also called -"skewing" or interlacing. +INTERLEAVE +The practice of selecting the order of sectors on a diskette track to minimize +access time due to rotational delay. Also called "skewing" or interlacing. -INTERRUPT]>A hardware signal which -causes the computer to halt execution -of a program and enter a special -handler routine. Interrupts are used -to service real-time clock -time-outs, BRK instructions, and -RESET. +INTERRUPT +A hardware signal which causes the computer to halt execution of a program and +enter a special handler routine. Interrupts are used to service real-time clock +time-outs, BRK instructions, and RESET. -IOB]>Input/Output Block. A -collection of parameter data, passed -to Read/Write Track/Sector, -describing the operation to be -performed. +IOB +Input/Output Block. A collection of parameter data, passed to Read/Write +Track/Sector, describing the operation to be performed. -I/O ERROR]>Input/Output Error. -An error which occurs -during transmission of data to or -from a peripheral device, such as a -disk or cassette tape. +I/O ERROR +Input/Output Error. An error which occurs during transmission of data to or +from a peripheral device, such as a disk or cassette tape. -JMP]>A 6502 assembly langauge -instruction which causes the computer -to begin executing instructions at a -different location in memory. -Similar to a GOTO statement in BASIC. +JMP +A 6502 assembly langauge instruction which causes the computer to begin +executing instructions at a different location in memory. Similar to a GOTO +statement in BASIC. -JSR]>A 6502 assembly langauge -instruction which causes the computer -to "call" a subroutine. Similar to a -CALL statement in BASIC. +JSR +A 6502 assembly langauge instruction which causes the computer to "call" a +subroutine. Similar to a CALL statement in BASIC. -K]>A unit of measurement, usually -applied to bytes. 1 K bytes is -equivalent to 1024 bytes. +K +A unit of measurement, usually applied to bytes. 1 K bytes is equivalent to +1024 bytes. -KSWL]>A vector in zero-page through -which input data is passed for -from the keyboard or a remote -terminal. +KSWL +A vector in zero-page through which input data is passed for from the keyboard +or a remote terminal. -LABEL]>A name associated with a -location in a program or in memory. -Labels are used in assembly langauge -much like statement numbers are used -in BASIC. +LABEL +A name associated with a location in a program or in memory. Labels are used in +assembly langauge much like statement numbers are used in BASIC. -LATCH]>A component into which the -Input/Output -hardware can store a byte value, -which will hold that value until the -central processor has time to read -it (or vice versa). +LATCH +A component into which the Input/Output hardware can store a byte value, which +will hold that value until the central processor has time to read it (or vice +versa). -LINK]>An address pointer in an -element of a linked chain of data or -buffers. +LINK +An address pointer in an element of a linked chain of data or buffers. -LIST]>A one dimensional sequential -array of data items. +LIST +A one dimensional sequential array of data items. -LOAD POINT (LP)]>The lowest address -of a loaded assembly language -program -- the first byte loaded. -Not necessarily the same as the entry -point address (EPA). +LOAD POINT (LP) +The lowest address of a loaded assembly language program -- the first byte +loaded. Not necessarily the same as the entry point address (EPA). -LOGICAL]>A form of arithmetic which -operates with binary "truth" or -"false", 1 or 0. AND, OR, NAND, NOR, -and EXCLUSIVE OR are all logical -operations. +LOGICAL +A form of arithmetic which operates with binary "truth" or "false", 1 or 0. +AND, OR, NAND, NOR, and EXCLUSIVE OR are all logical operations. -LOOP]>A programming construction in -which a -group of instructions or statements -are repeatedly executed. +LOOP +A programming construction in which a group of instructions or statements are +repeatedly executed. -LOW MEMORY]>The memory locations with -the lowest addresses. $0000 is the -lowest memory location. Also called -the "bottom" of memory. +LOW MEMORY +The memory locations with the lowest addresses. $0000 is the lowest memory +location. Also called the "bottom" of memory. -LOMEM]>APPLE's zero-page address -which identifies the first byte of -the available memory which can be -used to store BASIC programs and -their variables. +LOMEM +APPLE's zero-page address which identifies the first byte of the available +memory which can be used to store BASIC programs and their variables. -LSB/LO ORDER]>Least Significant Bit -or Least Significant Byte. The 1's -bit in a byte or the second pair of -hexadecimal digits forming an -address. In the address $8030, $30 +LSB/LO ORDER +Least Significant Bit or Least Significant Byte. The 1's bit in a byte or the +second pair of hexadecimal digits forming an address. In the address $8030, $30 is the LO order part of the address. -MASTER DISK]>A DOS diskette which -will boot in an APPLE II of any size -memory and take full advantage of it. +MASTER DISK +A DOS diskette which will boot in an APPLE II of any size memory and take full +advantage of it. -MICROSECOND]>A millionth of a -second. Equivalent to one cycle of -the APPLE II central processor. -Also written as "Usec". +MICROSECOND +A millionth of a second. Equivalent to one cycle of the APPLE II central +processor. Also written as "Usec". -MONITOR]>A machine language program -which always resides in the computer -and which is the first to receive -control when the machine is powered -up. The APPLE monitor resides in ROM -and allows examination and -modification of memory at a byte +MONITOR +A machine language program which always resides in the computer and which is the +first to receive control when the machine is powered up. The APPLE monitor +resides in ROM and allows examination and modification of memory at a byte level. -MSB/HI ORDER]>Most Significant Bit or -Most Significant Byte. The 128's bit -of a byte (the left-most) or the -first pair of hexadecimal digits in -an address. In the byte value $83, -the MSB is on (is a 1). +MSB/HI ORDER +Most Significant Bit or Most Significant Byte. The 128's bit of a byte (the +left-most) or the first pair of hexadecimal digits in an address. In the byte +value $83, the MSB is on (is a 1). -NULL]>Empty, having no length or -value. A null string is one which -contains no characters. The null -control character ($00) produces no -effect on a printer (also called an -idle). +NULL +Empty, having no length or value. A null string is one which contains no +characters. The null control character ($00) produces no effect on a printer +(also called an idle). -NIBBLE/NYBBLE]>A portion of a byte, -usually 4 bits and represented by a -single hexadecimal digit. $FE -contains two nibbles, $F and $E. +NIBBLE/NYBBLE +A portion of a byte, usually 4 bits and represented by a single hexadecimal +digit. $FE contains two nibbles, $F and $E. -OBJECT CODE]>A machine language -program in binary form, ready to -execute. Object code is the output -of an assembler. +OBJECT CODE +A machine language program in binary form, ready to execute. Object code is the +output of an assembler. -OBJECT MODULE]>A complete machine -language program in object code form, -stored as a file on a diskette. +OBJECT MODULE +A complete machine language program in object code form, stored as a file on a +diskette. -OFFSET]>The distance from the -beginning of a block of data to a -particular byte or field. -Offsets are usually given -beginning with 0, for the first byte, -1 for the second, etc. Also known as -a displacement. +OFFSET +The distance from the beginning of a block of data to a particular byte or +field. Offsets are usually given beginning with 0, for the first byte, 1 for +the second, etc. Also known as a displacement. -OPCODE]>Operation Code. The three -letter mnemonic representing a single -assembly langauge instruction. JMP -is the opcode for the jump -instruction. +OPCODE +Operation Code. The three letter mnemonic representing a single assembly +langauge instruction. JMP is the opcode for the jump instruction. -OPERATING SYSTEM]>A machine language -program which manages the memory and -peripherals automatically, -simplifying the job of the -applications programmer. +OPERATING SYSTEM +A machine language program which manages the memory and peripherals +automatically, simplifying the job of the applications programmer. -OR]>The logical operation comparing -two bits to determine if either of -them are 1. 1 OR 1 results in 1 -(true), 1 -OR 0 results in 1, 0 OR 0 results in -0 (false). +OR +The logical operation comparing two bits to determine if either of them are 1. +1 OR 1 results in 1 (true), 1 OR 0 results in 1, 0 OR 0 results in 0 (false). + +OVERHEAD +The space required by the system, either in memory or on the disk, to manage +either. The disk directory and VTOC are part of a diskette's overhead. -OVERHEAD]>The space required by the -system, either in memory or on the -disk, to manage either. The disk -directory and VTOC are part of a -diskette's overhead. -.br .nx appendix c.2