(C) Plyasunov D., Kazan
The 3-m room in 1996 (Section "Etudes") HACKER JOHN asked
about the effects on the curb in INSULT MD. I would like to
share it with the readers of reviews.
And start with the basics: no longer a
secret that every computer
there is a signal STAFF Sync. On his arrival ULA began to
deploy the image on the monitor, and scan speed is 8 pixels by 4
processor cycle (or 2 pixels per clock). Such work is repeated
50 times per second. Simultaneously with the advent of CSI
comes to the signal INT (more accurately say that the cause of
INT signal and the signal is
CSI. But more on this later). And I would like to
little fix VOLGAsoft'a:
image on the screen starts
based not on the signal INT, and
the signal CSI! Why am I singled out, I'll tell you in detail,
because I think it is very important. In all the computers
signal INT based on the signal CSI, and
generation circuit can be
different: where the signal is constructed
the leading edge of CSI, where
rear, where the row count is
in the beginning, and where at the end (do not tell "creators
")...
Ca. Ed.: All quite understandable: for
simplify the scheme for the Pentagon signal INT
formed with the arrival of (the leading edge)
IAC, which was very convenient for programming. No need to
calculate the delay. A standard machine INT is formed on the
trailing edge of CSI. The latter solution is more difficult for
an encoder, but there is compatibility with foreign programs,
using multicolor. There are still
Several methods of forming INT'a, but
consider them in this article makes no sense.
Well, and, respectively, while
between the arrival of IAC and the formation of INT can be
different! And therefore, MULTICOLOR, written
on one type of computer will not work on another. Because
and this sprites flicker on slower machines (like PROFI,
ATM), for example, have BOOT'e VAV'a
lost to MC PROFI. Now
are already appear remarks demoshki where
before starting your first offer to combine lines in BORDER'e
with screen (ECHOLOGY +, KSAGIFT).
Ca. Ed.: The following information is partly repeats the
already published by us materials MULTICOLOR'u, but we decided
give it completely because it is given in
more simple (close to a particular
problem) form.
And now, directly on the
screen: how many times it was written
REVIEW on the pages, the screen is
of the lines from 224 cycles each
(About 217 I do not know). See Figure 1.
Total number of such lines should be
312 (a PENTAGON'a 320, but it is not
dangerous). Multiplying, we find that
length of the interruption is equal to 69888 (in
PENTAGON'a - 71680). But not only that unlike computers. K
example, at RST7 PENTAGON, but not
everyone will have the right to go
hidden part INSULT'a, but from this the following fact: in his
PC INT formed on the leading edge of CSI, but on the other
PENTAGON'a types - on the back,
that's not the same BORDER.
Border
Screen
224 cycles
Figure 1.
The theory seems to be everything. Now shaped as letters: it
was noted that sweep speed is 2 pixels by 1 stroke. Hence,
that if we change the color
border very quickly, we can
achieve interesting effects.
Consider the command OUT (C), A:
This is the fastest team to send to the port, and it takes 12
cycles (there are even faster: OUT
(# FE), A - 11 clock cycles, but still
Replacement battery, how many
time will be ...), so the minimum possible "point" on
curb is 2 * 12 = 24 pixels, or 3 familiarity. Here's the
such points and will be our shaped as letters. And now an
example program deducing the letter A on the curb:
**
*
Template letters: *
****
*
* 140.
ORG # 8000
LD HL, # FE00; filling a region of size 257 bytes
LD DE, # FE01; byte # FF.
LD BC, # 100
LD (HL), # FF
LDIR
LD HL, # FFFF; address of the interrupt handler
LD (HL), # C9; here is the only team RET
DI; initialization IM 2
LD A, # FE
LD I, A
IM 2
EI
LOOP HALT; waiting for the arrival of INT
EI
LD BC, # 200, this latency
WAIT DEC BC; one run cycle takes 28
LD A, B; cycles. This gives some
OR C; advantage because increasing the value
NOP; BC to 8, the delay will increase by 224
JP NZ, WAIT; stroke, ie, 1 pixel down.
LD BC, # 00FE; C-port curb, B-color of the border
LD DE, # 0206; letter will be yellow on a red background.
OUT (C), D; upper band letters
OUT (C), E; only 12 * 4 = 48 cycles
OUT (C), E
OUT (C), D
OUT (C), B; on black, and 12 cycles
LD A, 10, a delay until the next line of 7 clocks
WAIT_1 DEC A; (4 +10) * 10 = 140 cycles
JP NZ, WAIT_1; Total: 48 +12 +7 +140 = 207 cycles
RET NZ; Team Dummy, complementary to 224
INC HL; 5 +6 +6 = 17 cycles
INC HL; 17 207 = 224 cycles. The line is finished!
OUT (C), E; further by the second line
OUT (C), D; Further, by analogy, many times
OUT (C), D; what height you letter.
OUT (C), E
OUT (C), B
...........................
, There may be other actions
...........................
LD A, # 7F; survey of the space key
IN A, (# FE)
RRA
JP C, LOOP
DI; recovery mode interrupts.
LD A, # 3F
LD I, A
IM 1
EI
RET
2
The procedure for drawing a point in
78 cycles.
To operate this procedure
need a sign to 1 KB. Idea
I threw my friend vytsepiv
her out of some toys.
140.
Input: B - coordinate Y, C - coordinate X.
PLOT LD H, # FA; to address # FA00 is a table
LD L, B
LD B, (HL); byte has already been formed
INC H
LD A, (HL)
INC H
LD L, C
OR (HL)
LD C, A
INC H
LD A, (BC); combine the display byte
OR (HL); resulting
LD (BC), A; and return it to the screen
RET
2
And now the program that produces a table in memory:
140.
CREAT LD HL, # FA00; start address table
, Should be "round" number
LD C, # 1940
CALL CREAT_1
LD C, # 1948
CALL CREAT_1
LD C, # 1950
CALL CREAT_1
140. LD L, B
INC H
XOR A
LD C, # 1920
LOOP_1 LD B, # 08
LOOP_2 LD (HL), A
INC HL
DJNZ LOOP_2
ADD A, # 20
DEC C
JR NZ, LOOP_1
LOOP_3 LD B, 8
LOOP_4 LD (HL), A
INC HL
DJNZ LOOP_4
LD A, # 80
LOOP_5 LD (HL), A
INC HL
RRCA
DJNZ LOOP_5
RET
CREAT_1 LD B, # 40
LD A, C
LOOP_6 LD (HL), A
INC L
INC A
AND # 07
OR C
DJNZ LOOP_6
RET
2
I would also like a couple of words
say about the command HALT. Execute commands similar ztoy
implement a series of commands to the NOP
the arrival of an interrupt. When it comes to interrupt, the
processor first DOVYPOLNYAET team on which he broke off, and
only then moves to the interrupt. NOP command four-stroke, so
when you run HALT may be four situations:
when INT come after a stroke NOP, two bars,
three bars and full implementation of this command. Therefore,
the length our whole procedure should be
multiple of four cycles. If
This will not be, INT will
arrive with different delays from
0 to 3 cycles, which will affect
shake the letters on the curb.
And one more thing. Always write synchronizers to your
effects on the curb for multicolor and for the effects of two
screens (blind, etc.).
At the request of the author we publish his address:
420073 Kazan, ul.Gvardeyskaya,
d.32, komn.323, Plyasunova Dimitri.
INTERNET E-Mail: pavel@open.ksu.
ras.ru
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