ZX81

Common Name: ZX81
Memory: 1k
Manufacturer: Sinclair
Type: Home Computer
Origin: United Kingdom
Year: April 1981 - 1982

The Sinclair ZX81 home computer, released by Sinclair Research in 1981, was the follow-up to the company's ZX80.

The case was black, with a membrane keyboard; the machine's distinctive appearance was the work of industrial designer Rick Dickinson.

Video output, as in the ZX80, was to a television set, and saving and loading programs was via an ordinary cassette recorder to compact audio cassettes

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Sinclair ZX Spectrum 48k

Common Name: Sinclair Spectrum
Memory: 16k & 48k
Manufacturer: Sinclair
Type: Home Computer
Origin: United Kingdom
Year: 1982 - 1984

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48k Sinclair Spectrum Facts: Rubber keyboard (40 keys) CPU Zilog Z80 A SPEED 3.5 MHz RAM 16k or 48k ROM 16k (Basic & OS) TEXT MODES 32 x 24 GRAPHIC MODES 256 x 192

KEYBOARD QWERTY-
Rubber keyboard (40 keys) with up to 6 functions each!
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
POWER SUPPLY External PSU, 9v DC, 1.4A (centre polarity = -ve)
PERIPHERALS ZX printer, ZX microdrives, Interface
PRICE 16k: 282 (France, 1983) - 48k: 365 (France, 1983)
16k: £99 (UK 1984) - 48k: £125 (UK 1984)

 

The Sinclair ZX Spectrum was a small home computer released in the United Kingdom in 1982 by Sinclair Research. Based on a Zilog Z80 CPU running at 3.50 MHz, the Spectrum came with either 16KB or 48KB of RAM (an expansion pack was also available to upgrade the former). The hardware designer was Richard Altwasser of Sinclair Research and the software was written by Steve Vickers (on contract from Nine Tiles Ltd, the authors of Sinclair BASIC). Sinclair's industrial designer Rick Dickinson was responsible for the machine's appearance.

Released by Sinclair in 1982 and available with either 16KB (£125, later £99) or 48KB (£175, later £129) of RAM and 16KB ROM. Remembered for its rubber keyboard and diminutive size.

The rubber keyboard (on top of a membrane, similar to calculator keys) was marked with Sinclair BASIC programming language keywords, so that pressing, say, "G" when in programming mode would insert the BASIC command GOTO. Programs and data were stored using a normal cassette recorder.

How to remove and wash your 48k Speccy rubber!

Note: The following instructions are followed out at your own risk..

1) Once the five screws and the rear is removed, you'll find that the keyboard membrane is attached to the pcb via two ribbons.

2) Skip to Step 3) if you do NOT need to remove the membrane.
Remove the ribbons if you need to also detach and remove the membrane that sits beneath the rubber keyboard - carefully hold both sides and pull gently until detatched - for both ribbons.

3) The keyboard can be removed from the top casing - unfortunately the only method is to first remove the top metal template where some of the extended speccy commands are printed.
This is normally glued underneath and will have to be re-glued if the stickyness does not hold when re-seated.

4) The rubber keyboard should now lift off the case easily.

5) I soaked my keyboard and template and gently washed it in warm soapy water. I wouldn't recommend anything else as harsher checmicals may remove the print.

6) Once washed, remove and dry thoroughly before attempting to re-install.

7) I spend 15 mintues washing in between the nooks and carnnies and was surprised how much of a difference both parts came up! Well worth the effort in my opinion.

8) Re-seat the keyboard and the template on top. Press firmly and test the stickyness - additional adhesive may be required to firmly attach the template (remember your speccy is over 26 years old!)

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Spectrum+ / +2

Common Name: Spectrum+ /+2
Memory: 128k
Manufacturer: Sinclair
Type: Home Computer
Origin: United Kingdom
Year: 1986

The 48K Spectrum gets a much needed solid keyboard and reset button, retailing for £180.

Shortly after Amstrad's buyout of Sinclair Research in 1986 came the ZX Spectrum +2 with an all-new keyboard, a built-in cassette recorder (like the Amstrad CPC 464) and dual joystick ports. Production cost cutting saw the retail price drop to £139-£149. Aside from the tape drive, revised keyboard and casing the +2 was essentially the same as the 128 model.

The initial version of the +2 departed from the traditional black plastics of other Spectrum models to favour grey. Subsequent models were in fact based on the +3 model with the unnecessary disk circuitry removed, easily distinguishable with the casing having returned to black (unofficially dubbed the +2A). A final revision purely for cost cutting saw the chip count reduced and manufacturing relocated for the final revision (unofficially dubbed the +2B).

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Spectrum 128 +2 +3

Common Name: Spectrum 128
Memory: 128k
Manufacturer: Amstrad
Type: Home Computer
Origin: United Kingdom
Year: 1987

The last Spectrum to be produced by Sinclair (although developed by Investronica of Spain) and based on the Spectrum+. New features included three-channel audio via the AY-3-8912 chip, MIDI compatibility, 128 KB of paging RAM, an RS232 serial port and an RGB monitor output.

ZX Spectrum +3 (1987)

Amstrad produced disk version based on the +2 but featuring a built-in 3-inch floppy disk drive (like the Amstrad CPC 6128). Most models featured distorted sound thanks to a design fault later rectified in the "4.1 ROM" model. Retailed for £249 then later £199 and the only model capable of running CP/M.

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