Monday, 11 November 2013

The Centre for Computing History in Cambridge

The Centre for Computing History in Cambridge

The Centre for Computing History is a short walk from Cambridge city centre and is home to a sizeable collection of computers. The museum actively encourages visitors to sit down, try out a few games and even have a go at BASIC programming.

The museum's collection ranges from mechanical calculators and mainframes to home computers and games consoles. Most of the home computers and consoles are switched on and running classic games.

If you're interested in the history of computing (particularly home computing), the centre is the perfect place for a day out.

MITS Altair 8800 computer

Relaxen und watschen der Blinkenlights - the MITS Altair 8800

Commodore PET 2001

PRINT CHR$(205.5+RND(1)); - Commodore PET 2001

ZX Spectrum 48K

PLOT 48,56:DRAW 160,0,65536 - ZX Spectrum 48K

Intel MDS 80 Microprocessor Development System

Intel MDS 80 Microprocessor Development System

HP1000 F Series minicomputer

HP1000 F Series minicomputer

Friday, 18 October 2013

Video Gaming 1979-1989 at the NCCD

Video Gaming 1979-1989 exhibition at The National Centre for Craft and Design

The National Centre for Craft & Design is hosting an event to celebrate the golden age of video games, "Revolution in the Bedroom, War in the Playground: Video Gaming 1979-1989". The exhibition runs from 19th October to 5th January in the main gallery.

The exhibition focuses on bedroom programmers, 8-bit games design and magazine cover art with classic games running on several computers. If you're in the Sleaford area, it's definitely worth a visit.

ZX Spectrum circuit schematic diagram by Simon Patterson

Detail from Simon Patterson's 15 metre chalkboard circuit diagram

artwork by Oliver Frey

Cover artwork by Oliver Frey

Video Gaming 1979-1989 exhibition

Thursday, 1 August 2013

ZX Spectrum Koch (Lévy C) Curve

ZX Spectrum Koch (Lévy C) Curve

A few years ago I submitted a couple of type-in programs (C-Curve and Curtains) to Your Sinclair and they featured in the penultimate issue (August 1993).

Encouraged by a shiny new YS badge I sent off a new batch of programs. Unfortunately it was too late. The September issue would be Your Sinclair's "Big Final Issue".

C-Curve is one of the simplest fractal curves. It starts with a straight line. To find the next iteration, each line is replaced by two lines at 90°:

C Curve fractal

Here's a later 69 byte version of the program which plots the fractal in approximately 1.52 seconds! Assemble with Pasmo (pasmo ccurve.asm ccurve.bin), load the binary to address 65467 in your favourite emulator and run using RANDOMIZE USR 65467 :-)

  org 65467
  ld de,49023 ; d = position on x axis
              ; e = position on y axis
  ld bc,3840  ; b = number of iterations
              ; c = initial direction
  djnz DOWN

  ld a,6      ; check direction
  and c       ; c=0, left
  rrca        ; c=2, up
  rrca        ; c=4, right
  add a,a     ; c=6, down
  dec a
  jr nc,XMOVE

  add a,e     ; adjust y position +/-1

  ld e,a      ; calculate high byte of screen pos
  xor e
  and 88
  xor e
  and 95
  ld h,a
  sub h

  add a,d     ; adjust x position +/-1

  ld d,a      ; calculate low byte of screen pos
  xor e
  and 199
  xor e
  ld l,a

  ld a,7      ; calculate bit position of pixel
  and d
  ld b,a
  inc b
  ld a,1

  xor (hl)    ; plot
  ld (hl),a

  inc c       ; turn 45° clockwise
  call RECURSE
  inc b
  dec c       ; turn 90° anti-clockwise
  dec c
  call RECURSE
  inc b
  inc c       ; turn 45° clockwise

Finally here's a short type-in program to poke the code into a real Spectrum!

Thursday, 4 July 2013

Silicon Dreams & The Vintage Computer Festival

The Centre For Computing History at Silicon Dreams

This weekend the biggest event in the U.K.'s retro computing calendar will be hosted at the Snibston Discovery Museum in Leicestershire. The Vintage Computer Festival follows 2010's highly successful event with most of the main exhibitors returning. Some of the highlights include:

  • Raspberry Jam - a hands-on workshop for the Raspberry Pi single board computer organised by the Centre for Computing History.
  • The Amiga is well represented at the show with demonstrations of MorphOS 3.2 and the latest AmigaOne X1000.
  • 15+ exhibitors will be displaying a wide range of historic / unusual computers including RISC OS running on the Raspberry Pi.
  • Look out for the Spectranet ethernet board in action. Tweet direct from a ZX Spectrum complete with nixie tube tweetometer!

The event runs from 5th - 7th July. Tickets are £15 for the day, or £20 for the weekend. We'll be there when the gates open at 10am. Is anyone else planning to attend?