ZX Computings - OpenLibra

DOS Disc Operating System
— a computer operating
system held on magnetic disc
rather than in ROM. An
initialisation process will copy
the operating system into
memory whenever the
computer is first turned on.
Also an operating system
which controls the disc
themselves and may
supplement, rather than
replace, the computer's
original operating system.
Duplex A mode of data
transmission where each
station can send and receive
simultaneously.
Dynamic (Memory) Random
Access Memory (RAM}
requiring constant refresh
signals but normally using
less electrical power than
static memory,
EAROM Electrically Alterable
Read Only Memory. Typically
taking 10 mSec to erase and
1 msec to write, this nonvolatile
storage might be
better considered as 'Read
Mostly Memory' as the write
capability is likely to be
limited to say 100,000
cycles.
Edit Alteration of text in
program or data files. Often
necessary, some systems
make editing easier than
others.
EPROM Erasable
Programmable Read Only
Memory. Writing typically
takes one minute and erasing,
by ultra-violet light, 10
minutes or longer.
Firmware Instructions or data
permanently stored in ROM.
Floppy (disc) A mass-storage
device comprising a soft
(floppy) plastic disc with
megnetisable surface on
which data is recorded and
may be accessed rapidly by a
moving read/write head. The
disc, either 8" or 5%"
diameter, rotates inside a
protective cardboard sleeve.
FORTRAN Formula
Translation, an early and still
popular high-level
programming language,
mainly used for scientific
purposes.
Golfball A type of typewriter
(or the print head from which
it gets its name) in which the
print characters are embossed
on the surface of a sphere
very similar in size to a
golfball. Rotation of the
sphere brings the appropriate
character into line for each
required impression. The
process is usually slow (1 5
cps) but of good quality.
Hard Copy A
computer printout or
listing on paper.
Hardware The
physical elements of a
computer (contrasted
with software).
High-Level Language
Programming
language usually
claimed to resemble a
natural language, and
with powerful
instructions, each
generating several
machine language
instructions. Examples include
BASIC, COBOL and
FORTRAN.
Intelligent terminal An
input/output device
which includes its
own logic circuits and
memory so that, for
instance, data may be
validated or changed
in format before
transmission to the
main computer.
Interactive A working
arrangement under
which the computer
reacts immediately to
respond to any
mistakes which may
be made by the user
120 ZX COMPUTING SUMMER 1982