Sinclair And Clones Computer Show

Anonymous Coward writes "The Sinclair ZX Spectrum seems to be alive and well with 'Your Sinclair' magazine being relaunched at WH Smiths newsagents, and according to this, there is a Spectrum and clones computer show in Norwich, England, (the other Sinclair formats and clones include the QL, SAM Coupe, Timex/Sinclair, ZX81, Z88 etc). It looks like it could be fun. I must get my Spectrum out and play some games."

Comments

What fun!

[reality-bytes]

I must have a dozen Spectrums of various iterations kicking about here - including 2 of the early blue-key types complete with microdrives and microprinters.

I even have a couple of 'docking bases' which allowed (IIRC) you to network up to 16 Speccys together in series.

It just really suprises me that there is enough interest still going in the spectrum to actually warrant a magazine relaunch.

'Back in the day' I used to own my spectrum primarily for gaming. The magazine to have was 'Crash' (complete with cover-mounted cassette). Now there was a real magazine; it wasn't even glossy ;)

Popularity?

[MBCook]

This brings up a question that I've been wondering. Sinclair machines were very popular over in Europe, right? Could anyone tell me why they took off over there and not over here?

Either way, neat show. Wish I could go.

Re:Popularity?

[pesc]

Sinclair machines were very popular over in Europe, right? Could anyone tell me why they took off over there and not over here?

The first machine I bought was a Sinclair ZX-80. I bought it because it was very inexpensive. It was the first complete system to sell for under 100 pounds, which was revolutionary cheap for the time.

The circuitry was amazing. It had 1 KByte of memory which also serverd as video memory! I remember that someone crammed in a chess program into that. The original BASIC interpreter was 4K. (Why are all program so damned big nowadays?)

To make the system very cheap, it had no dedicated video circuitry! You stored characters in RAM and ended each line with 0x76. (The less text you had on display, the less memory it used.) To display the text on the screen, you set a special bit in hardware and jumped to the RAM character buffer. The CPU would start to fetch instructions from the text buffer, but the hardware would clear all bits fed to the CPU (00=NOP). Instead the RAM output was fed to the BASIC ROM which now served as a character generator. When the end of line was reached, the 0x76 code was fed to the CPU which interprets that code as a HLT (halt) instruction. So no more bits were fed to the display until horizontal sync, which gave the CPU another interrupt. So with a minimum of 74xx logic gates video text could be generated at low cost and extremely low memory requirements. Of course, the screen went blank when executing BASIC code.

It was an amazing machine and I have many fond memories playing with it. The schematics was included so you could do some hardware hacking as well.

Re:ooh does anyone remember this

[forgotten_my_nick]

or the all time favorite..

poke 23659, 0

or

poke 23613, 0

Scary that I can still remember them.

Great learning machine

[jon514]

I got a Spectrum when they first appeared (aged about 13). I found it was a great machine to learn about computing - you had a Sinclair Basic interpreter as the main interface & Z80 assembler underneath. I spent many happy hours coding & hacking games on it. It & its predecessor, the ZX81, were what got me hooked on IT & software development. One of the great things was full manual it came with & fairly straightforward books you could buy detailing the full ROM disassembly!

I wonder whether those at that age now find it as easy to learn as much about the basics of computing? How hard is it to understand the fundamentals of how the machine really works, when most teenagers probably have a PC & Windows OS to play with?