ZX Format #06 29 июля 1997

Программирование

Programmers - the exchange of experience: programming Multicolor effects.

  Manufacturing multicolor

music by DNK
(C) MIK. VIRT GROUP.
_______________________________

 This article is a direct logical
continuation of the previous dedicated to curb the effects. 
Therefore, for the best understanding set out below, I advise 
you 

  read the previous article.

 Part of the first and only.

 Multicolor can be defined as such
presentation graphics, and
which with the help of software tools
achieved in obtaining a familiarity
more than two colors. Note:
Please note that receipt of
more than two colors within the byte
owned by familiarity, nevozmozhmo
by the following type of technology.

 Now it's time to move to a description of the technical side 
of multicolor. As I noted earlier, the principles of the 
curb-effects and multicolor similar. The most problematic

is fixing them in time.
The very existence is based multicolor
on the fact that the construction of each line
the main screen, ULA (group Chipset
Responsible for graphics output) re-
reads the information from the attributes and
If, after the construction of a fragment of the screen,
before the start of construction of the next line
replace the data describing these lines,
then the next line will be constructed in accordance with new 
data about the attributes. So, in order to obtain multicolor, 
you need to make the following steps:


 1. Wait for the signal INT.
 2. Pause before the start of
construction of region of interest (on
actually lower at the time that you
necessary to transfer the necessary information
In the Attributes).
, 3. Wait until you have replaced the attributes will be built.
 4. Throw in their place the new data.
 5. If necessary, pause =
When you build a single line - the time
spent on items 3 and 4.

  6. Cheerfully proceed to step 3.
 7. Do something useful.

 By tradition, will not clog your head
empty writings, and immediately move on to the suit.

 Arrange in a multicolor line of zero ,0-5
familiarity.


  ORG # 8000

       DI

       LD HL, # BE00

       LD DE, # BE01

       LD BC, 256

       LD A, H

       LD (HL), # BF

       LDIR

       LD I, A

       LD A, # C9; Processor

        LD (# BFBF), A; interrupt

       IM 2; command RET
MAIN EI

       HALT

       DI

       LD A, 63;!
LOOP1 DS 52, 0;!

       DEC A

       JR NZ, LOOP1
; Loop waiting for constructing
; Border, the time depends
; The type of computer


  LD HL, DATA

       LD A, 8
LOOP2 LD DE, # 5800

       LDI; 16

       LDI; 16

       LDI; 16

       LDI; 16

       LDI; 16

       LDI; 16
 ; Transfer attributes


  LD DE, 0
 ; No significant team
 ; Needed something to spend
 ; Time


  DS 23, 0;!

   , Waiting up to 224 cycles (for
 , So most Comper
 ; Building line.


  DEC A

       JR NZ, LOOP2


  LD A, # 7F

       IN A, # FE

       RRA

       JP C, MAIN


  IM 1

       RET

DATA DB ......
; Data about the attributes.

 All time delay in this example
made under the Scorpion. If you have another type of computer 
you'll have to choose the numbers in the rows marked with (!). 

 Actually, that's all you can say
this issue and I hope that you will be able to apply this 
knowledge. _______________________________