Appendix D – Glossary of terms
Application – A program set up according to the appropriate machine conventions.
Bank – 16K chunk of memory, always on a 16K boundary in the logical address space.
Binding – this refers to switching a bank to a segment or to switching a file device to an particular stream with the CLI
BLINK – the name given to the Z88’s gate array chip. The chip handles the screen, serial port, keyboard, memory switching, interupts etc.
Card Manager – this refers to the code which deals with inserting and removing ROM cards. The basic rules are that all interchange should be done from the Index and that the machine is switched ON. If an application is using a ROM card then the card’s slot is displayed in the next to the application name in the Index window. RAM cards can only be inserted, never removed. EPROMs can be inserted and removed at most times, but obviously not while the Filer is actively reading or writing slot 3.
CLI – Command Line Interpreter. This is used to simulate the keyboard and to rebind streams.
Director – synonym for ‘Index’ (the name used for it while much of the code was being written, hence ‘dc’ calls not ‘ic’ calls).
DOR – node in tree structure used in applications and the RAM filing system.
Explicit Filenames – a filename which includes the device and root directories. For example “queries.pip” might become “:RAM.1/office.dir/queries.pip”
Extension – up to three letters after the filename, usually used to classify the file. eg. you might add .pip to all your PipeDream files to aid identification.
Filter – conceptual ‘object’ (actually a set of routines) which perform transformations in a byte sequence. Also see Printer Filter.
Handle – A handle is a 16 bit value, usually returned in IX, used in file-like operations (eg. files, filters etc.) to direct input and output. For example, a handle is returned when a file is opened and is subsequently used whenever the file is accessed. A file can have several handles associated with it and attributes like the sequential pointer into a file are associated with each handle and not with the file itself. There are a finite number of handles in the machine, initially around 100, and the current number available is reflected in the high word of the sequential pointer associated with a handle value of -1. (In BASIC PTR#-1.)
Logical address – Address which the Z80 CPU ‘sees’, ie. a standard 16-bit Z80 address. See also Physical address.
MOS – machine operating system. Also referred to as OZ.
Page – 256 byte chunk of memory, on a 256-byte boundary. This is the basic unit of memory on which the allocation routines operate.
Physical address – 24-byte address referring to an actual memory location (only 22 bits are significant, giving an addressing range of 4Mb).
Pre-emption – The suspension of a process, normally prior to the main body of a system call. See also Logical address.
Printer Filter – This is a filter controlled by the Printer Editor. It allows applications to use special printing effects by specifying filter codes and letting the filter generate codes appropriate to the printer actually in use.
Process- A particular instantiation of a program (normally an application).
Segment – 1) One of the four 16K portions of the logical memory map. 2) One of the portions of a filename separated by ‘/’, ie. a file or a directory name.
Slot – 1) One of the three physical holes in the front of the machine, which can accept a RAM, EPROM or ROM card. The internal memory of the machine is thought of as Slot 0. 2) The transmission frame for a character of data in the serial system. ie. the byte to be transmitted plus appropraiate start and stop bits. 3) Concept used in PipeDream. Roughly approximates to a spreadsheet cell.
Stream – This is a communication channel with an associated handle.