Tandy PC-6 - LSI Pin Functions

LSI (Pin Functions)
IC1 I HD61747B20
IC2
,
HD61747B25
Pin No. Signal Name
In/Out Function
1'\,,4
D1,2,4,8
In/Out Data in/out (D1, D2, D3, D4)
5 INT
In Interrupt signal from RAM
6'\,,18 KM'\"K1
In/Out
Key signal for keyboard
19
SW
In/Out Switch signal. GND at switch
"OFF" and VDD1 at switch
"ON".
20'\,,24
V5'\"V1
Out Display voltage. Divided vol-
tage from VDD1.
25,26 PG2,PG1 Out, In
CPU internal clock
27'\,,72 R15'\"R7
Out Display signal
73 GND In GND
74 CE2
In/Out
Chip designating signal.
Select RAM
or other devices
75 CE1
In/Out Select RAM or other devices
76
VDD1
In Power source
77
VDD2
Out VDD1 output from the LSI.
VDD1
at switch "ON" and
GND switch
"OFF".
78, 79 1/)1,1/)2
In/Out Clock pulse
80
OP
In/Out Operation signal
~ ~:e: 8 0 w ~ ~ b: ~ 0: ~ ii ~ ~ ~
o 0 U U<:J a1
> > b1
c1
d1
e1
a2
b2
c2
d2
e2
a3
b3
c3
d3
e3
a4
b4
c4
N ..... LO O ..... NM<::t
~~a:~~ o:o:o:a:a:~~<g:g~~
01
02
04
08
INT
KM
K12
K11
K10
Kg
K8
K7
K6
K5
K4
K3
K2
K1
SW
V5
V4
V3
V2
V1
IC4
,
MB64H193
37
36
100
02
106
03
ADO
04
107
E
AD1
S1
VSS
VSS
AD2
S2
AD10
B2
AD3
B1
DE
CSO
AD4
CS1
AD11
CS2
LD
coco
N
0
(J)
r--
0
co
en
""
M
12
0
0
00
0 0
s
(fJ (fJ
(fJ (fJ
« « ««
«
«
>
a:
U
U
U U
25
13
24
Pin No. Signal Name In/Out
Function
1,2
100,106 In/Out
Data in/out
3
ADO
Out
Address signal
4
107
In/Out
Data in/out
5
ADl
Out
Address signal
6
V55
In
Power source
7,8,9 AD2, 10,3
Out
Address signal
10
OE
Out
Output
enable
11'V18
AD4'VAD12
In/Out
Address signal
19
VDD
In GND
20
RW
Out Read/write signal
22'V24
CS6'VCS3 Out
Ch ip enable signal
25'V27
C52'VC50
-
NC
28,29
Bl, B2 Out
Buzzer signal
30 52
In
GND
31 V55
In
V55
32
51
In
GND
33
E
-
NC
34'V37
D4'VDl
In/Out
Data in/out
38
OP
In Operation signal
39,40
C2,Cl
In
Clock pulse
41 VDD2
In
Power
sou rce
42
CE
In Chip enable
43
VDD
In GND
44'V48 103'V105
In/Out Data in/out
-8-