It was about 4 onths ago when I was over at the Liverpool
Nascom Club that I saw for the first time this superb board in
operation, The board nad started off asa private project but
when completed it waz in such demand that it became very
Commercials The main designer was Stuart Holes and most of the
Software was produced by Joe Savlini.
For my money I got 2 12x8 board, an I/O decode PROM,
reasonable design and construction notes and a cassette
Containing seme short programs which test the different features
of the board and also give an insight into how ta program it.
The programs are in Pascal which makes using the procedures to
access the various parts of the board very easy.
Features of the Graphics Animation Board
1. Nas-bus compatible on an @%%12* double-sided board. The board
16 not thraugh-hale plated and appro>. 325 track-pins need to
be put an before construction can start. Hard work but 16 has
kept the cost of the board down.
Fully buffered data and address bus.
S. ALL functions are decoded as I/O by the provided PROM
Including the Nascom I/O ports therefore the board does not
take up any address space.
4. The heart of the video section 15 the THS9929 graphics
processor together with 16k of dynamic RAM.
S. The processor can produce a resolution of 256 by 192 wth 16
colours with the output from the board being in the form of
Rey, B-Y and Y buffered ta 7Sohms. This means that the output
from the chip must be processed further to provide a signal
capable of driving a TV or colour manitor. The luminence
signal (Y) can be directly connected to the input of a black
Komhite monitor to give # shades of grey picture but thi is
a waste when the chip is producing 16 beautiful colours.
6. The processor alsa produces 32 sprite planes containing
thirty-two Bx, 161 or 52”32 pixel sprites.
7. The position of each sprite on the screen is given by
speci fying its XY co-ordinate.
8. If two sprites collide ie. one sprite is moved so some of its
8x8, 16x16 or 32x32 pixels overlap another sprite, a sprite
coliision flag is set allowing immediate collision sensing
without ‘peering” the screen RAM. This makes the programeing
aspect of moving graphics very easy.
9. Magnification and size factors for each sprite are loaded in
the sprite attribute table enabling a change froa 8x8 to
This is an OCR’d version of the scanned page and likely contains recognition errors.