*** IRON ***
PENTAGON-128. CONNECTING KEMPSTON-NAVIGATION.
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If you download a computer game programs, then perhaps
noticed that almost all the games can be controlled not only
from the keyboard, but with a joystick. Moreover, as the right
to choose offers several types of joysticks - KEMPSTON,
SINCLAIR, CURSOR, etc.
KEMPSTON-interface is a parallel input port
information from the joystick on the data bus kompyutera.Etot
port has an address of 31, but is commonly used cruder decoding
the address when the port is chosen zero-state address bus or
A5 A6, because is not typically used several external devices.
In addition to addresses in the port selection part signals the
microprocessor - IORQ, RD, which corresponds to a reading of I
/ O port. From bytes read media interest under 5 bits D0 ...
D4, which reflect the state of the joystick contact:
D0 - "RIGHT" D1 - "LEFT"
D2 - "DOWN" D3 - "UP"
D4 - "FIRE"
At various conditions of the joystick with his numbers read:
STATE NAVIGATION D0 D1 D2 D3 D4 NUM
BASELINE 0 0 0 0 0 0
RIGHT 1 0 0 0 0 1
LEFT 0 1 0 0 0 2
DOWN 0 0 1 0 0 4
UP 0 0 0 1 0 8
RIGHT, DOWN 1 0 1 0 0 5
LEFT, DOWN 0 1 1 0 0 6
RIGHT, UP 1 0 0 1 0 9
LEFT, UP 0 1 0 1 0 10
FIRE 0 0 0 0 January 1916
RIGHT, FIRE 1 0 0 0 January 1917
LEFT, FIRE 0 1 0 0 January 1918
DOWN, FIRE 0 0 1 0 January 1920
UP, FIRE 0 0 0 1 January 1924
RIGHT, DOWN, FIRE 1 0 1 0 21 January
LEFT, DOWN, FIRE 0 1 1 0 January 1922
RIGHT, UP, FIRE 1 0 0 1 January 1925
LEFT, DOWN, FIRE 0 1 0 1 January 1926
Note that after power up or pressing the RESET all
580BB55A ports are configured in input mode of informatsii.Krome
Addressing the port "A" is chosen such that makes it possible
to use it as a joystick interface, which can be connected
as shown in Figure 1. The joystick will be chosen at zero on
Tire A5, RD, IORQ, which corresponds to addressing
KEMPSTON-INTERFACE.
4 / RIGHT K
580VV55A RA0 / E
3 / LEFT M
RA1 / P
2 / S DOWN
PA2 / T
1 / UP O
Pa3 / N
40 / FIRE
RA4 / A
39 M
RA5 R1-R5 About
38 10 ohms Fig.1 TH
PA6 C
37 t
RA7 +5 V and
K
After the interface was collected, make sure it
performance. It's enough to run a simple program:
10 LET A = IN 1931
20 CLS: PRINT AT 10,10; A
30 PAUSE 15: GO TO 10
In the neutral position of the joystick handle and properly
collected by an interface circuit in the center of the screen
should display "0". When the slopes of the arm will receive
adequate numbers, as recorded in the table above.
