Sinclair Spectrum - 1982

The ZX80 and 81 had both been very heavily criticised. Neither had a colour display, they were slow with very poor keyboards and unreliable program loading and saving. Better things were around (see lots below). The result, in 1982 was a computer so good, it even got a name, the Sinclair Spectrum. How did it do in terms of improvements?

Colour - yes, though not quite as most other manufacturers saw it. There was a graphics mode of 256 pixels wide by 192 pixels high but colours (foreground and background) were only selectable on the text resolution of 32 by 22. That meant that if you wanted the first pixel in the top left-hand corner to be red on yellow then every first 8 pixels in the first character row were also red on yellow. Amazingly, if you look at some of the Spectrum games you would almost be unware of this restriction and some incredible graphics were produced.

Keyboard - the "dead flesh" rubber keyboard was surprisingly good, nowhere near a proper keyboard but at least there was some feedback. Sinclair's keyword entry did, however, reach new heights. The K key now represented K, k, LIST, + LEN or SCREEN$ according to where you were on a line of BASIC and whether you had used the SHIFT key, the Symbol SHIFT key or "extended mode" where you pressed both SHIFT keys. A number of companies produced "proper" keyboards, the most popular ones I remember were from DKTronics (who produced all sorts of Sinclair peripherals) and, my personal favourite, the Saga which had Shift keys all over the place to try to make the Keyword entry system less painful.

Memory - you could choose between 16Kb (hardly anyone did, these are now quite rare) or 48KB. None of it moved and no crashes.

Program load and save - this was still to cassette though it finally worked for most people. The claim was that Sinclair went out and bought every cheap cassette recorder they could find for testing. Interestingly, the cheaper the recorder, the better it worked! Loading and saving was at around 6.25 seconds per 1K. A 48KB program took around 4 and a half minutes to load. The system was so reliable that some companies actually wrote their own load routine which was installed from the tape first then the actual program (normally a game) loaded at twice the speed.

The Spectrum was an amazing success, selling millions worldwide. It also produced an incredible number of companies selling hardware (like the keyboards) and an enormous variety of software. The latter did not just mean games. There were two other varieties of BASIC you could load, BetaBASIC and MegaBASIC (the latter was actually given away free with Your Spectrum magazine. These added better programming capabilites as found in computers such as the BBC Micro and, very importantly, got rid of the Keyword typing system so you could just type letter by letter. BetaBASIC still offered keyword entry for anyone who was addicted to it!

BASIC is by no means the only programming language available. On my own Spectrum I could load Forth, Pascal and C amongst others. It managed to be both a games machine and an incredibly powerful system for those who (like me) lacked the cash for something better.


No mention of the Spectrum would be complete without looking at some of the technology that came alongside it. Out of the box, the Spectrum connected to the tape deck, power supply and TV. There was also a large edge connector (basically, the end of the circuit board). This edge connector was utilised for a number of items, some from Sinclair and many from other companies:

Interface 2 - I have put this one first as it was the simpler. This provided two joystick ports and a socket into which you could insert ROM-based software. ROM-based software meant instant loading and totally reliable but was more expensive to buy and impossible to copy (an awful lot of illegal copying went on with the Spectrum, all you had to do was connected the earphone output of one cassette deck to the microphone input of a second and mess around with the levels). Many other joystick interfaces were available though the "official" one was unusual in offering two sockets for two joysticks.

Interface 1 - By far the cleverer of the two. This provided 3 exciting interfaces:

1. RS232 serial port - this meant you could print to proper printers rather than just the Sinclair ZX Printer.

2. Network port - not quite what you might expect based on networks we have today. This worked at 100KB per second (most home users will be using wireless at 56MB per second (almost 1000 times quicker) and the computers needed to be no more than around 10 feet apart. Each end had to be told to send data or receive data though Sinclair had provided a program to send the same data to every computer listening and another so that a computer could listen to anyone sending and copy what was sent to the printer. I remember great excitement over this port though never saw it in use.

3. Microdrive port. It is probably difficult to describe a Microdrive now. Most people do not even have floppy drives in their computers. Imagine a program of less than 48KB (if you want to try this, you will have a file called ftp.exe in your system32 folder which is 42KB long), now save that file to your hard disk - if you watch very carefully you will just see the light flash! Now, if you have one, save it to a floppy disk and see it take just a few seconds. Much of that time is actually taken up with reading the index of the disk, finding a spare space, tracking the disk head to the right spot (the disk is 80 concentric tracks of information) then the computer has to wait for the right sector to come under the disk head and write the data. Quite a lot of activity for just a few seconds. Now lets step back in time to a Spectrum, you rummage through your tape draw for the one you want then insert it into your cassette recorder. Next you rewind the tape to the start (because you never remembered to do it when you finished last time) then press LOAD"" on the Spectrum then press play on the recorder and wait around 4 minutes. Most times you could then get started with whatever you had planned. You could get floppy disks in those days, these were 5 1/4 inches in diameter and could hold about 100KB. They actually were floppy as the square cover was flexible. The trouble was they cost a lot of money plus a lot more to buy an interface to plug between your Spectrum and the disk. I had one of these later on (prices fell and I earned more) but in the early days they were virtually unaffordable. Sinclair came up with a spectacular alternative in the Microdrive..

(A slightly more rugged alternative was the Rotronics Wafadrive.)