The Sinclair ZX Spectrum was one of the most popular European computers of the 80's. Two models were launched: one with 16 kb RAM and one with 48 kb RAM.
One of its most "interesting" characteristics is its keyboard! Some keys have more than five (!) functions! It is impossible to type BASIC keywords letter by letter, instead you have to use function keys. A lot of peripherals and programs were developed for this computer. It seems that several models of this computers were launched (at least 3), but I've no technical details about them. It was replaced in 1984 by the Spectrum + and in 1985 by the Spectrum 128.
Alan Wilson reports to us :
The 16K version of the computer had only the 16K ram chips loaded, while the 48K version had both banks full.
To keep the prices down Sinclair used faulty 64K chips (internally 2 X 32K). All the chips in the 32K bank of RAM had to have the same half of the 64K chips working. A link was fitted on the pcb in order to choose the first half or the second half.
It was possible with a few logic chips for the experimenter to have access to the faulty 32K bank.
The Spectrum had a wonderful feel to it, almost organic imho. I spent for too much of my youth tapping away at this little gem.
I had the original rubber key 48K, the + and the +2, but my heart will always be with that little rubber keyed masterpiece.
Monday 21st June 2010
Mark (UK)
The 3.5 Mhz CPU speed was quite fair for 3D games, which run more smootly on the Spectrum than on a C64 for example with 1Mhz (or 1.6Mhz?) CPU (there was one where you had to deploy towers on a space station and another one where you had to run through a egyptian tomb, I forgot the names$ does anybody remember VU3D from Psion btw.? :)))). No VIC or SID chips unfortunatelly :( However it''s a 8bit CPU, the Z80 has instruments for 16bit operations and plenty of registers (A,B,C,D,E,H,L which are the 8 bit ones and BC, DE, HL which are the 16bit ones!), which were really great to work with that time! I still had the guy in one of the boxes somewhere in the basement :) :(
Friday 21st May 2010
Noir (Hungary)
There should be important additional info in description at site about graphics of Zpectrum:
Each 8x8 pixel block have: 3 bit foreground color, 3 bit background color, 1 bit brightness, and 1 bit flashing.
http://wapedia. mobi/en/Attribute_clash
Wednesday 8th April 2009
User
NAME
ZX SPECTRUM
MANUFACTURER
Sinclair
TYPE
Home Computer
ORIGIN
United Kingdom
YEAR
April 1982
END OF PRODUCTION
1984
BUILT IN LANGUAGE
Sinclair Basic
KEYBOARD
QWERTY rubber keyboard (40 keys) with up to 6 functions by keys !
CPU
Zilog Z80 A
SPEED
3.5 MHz
RAM
16k or 48k (42k left for programming)
ROM
16k (Basic & OS)
TEXT MODES
32 x 24
GRAPHIC MODES
256 x 192
COLORS
8 with two tones each (normal and bright)
SOUND
1 voice / 10 octaves (Beeper)
SIZE / WEIGHT
23 x 14,4 x 3 cm / 550g
I/O PORTS
Expansion port, tape-recorder (1200 bauds), RF video out
ShareThis
(France, 1983) - 48k: 365 
