#FLICKER FREE SCREEN FULL#

A description of the Amazing Active Display was included in an advert published in Sync magazine This is also revealed in an interview with Ron Bissell that appeared in He reveals that it was his Macronics partner Ron Bissell that developed the technique. 1 (April 1982, 'Software Overview', page 51), but in an interview with Ken Macdonald in Home Computing Weekly magazine (6th December 1983, page 72) The Amazing Active Display technique was attributed to Ken Macdonald in Sinclair User Both were reported in Interface magazine, Vol. 7, September 1981, page 113) was from the partnership of Ken MacdonaldДЄnd Ron Bissell (later to be known as Macronics) who released their Amazing Active Display, which was a machine code pause routine.ДЄt a similar time, Dr. The first (source: Personal Computer World magazine, Vol. Soon produced machine code programs that were structured to divide their time between running the program functionality and generating the TVДisplay. It is not possible for a standard BASIC program to run and produce a steady TV picture (also known as a flicker-free display), but companies In the USA NTSC PAL television system there are 60 frames per second and so a single frame spans 16.67ms. In the UK PAL television system there are 50 TV frames per secondДЄnd so a single frame spans 20ms.

#FLICKER FREE SCREEN FULL#

The keyboard scanning routine is tuned such that it occupies the remaining time within the TV frame, and henceДЄn iteration of the loop always takes the time period of a full TV frame. Iteration it checks the state of the keyboard and if no keys are being pressed then it outputs the visible lines forming one scan of the TV In this state, a carefully timed routine within the ROM loops continuously to generate the TV display at precisely the right time. The ZX80 was not designed to produce a steady display whilst running a BASIC program, but only when the computer was waiting for user input.

Flicker free screen