
I
,I
I
SECTION
ONE
PRODUCT
OVERVIEW
SOSSA
PROCESSOR
CARD
This card
combines
a
buffered
and fully expandable
808SA
microprocessor
withonboard
RAM and
PROM sockets.
The
7801
includes
1K
byte
of
RAM
with
sockets
for
up
to 4K. and sockets
for
up
to
8K bytes
of
ROM
or
EPROM. An STO BUS system using the
7801
card
can be expanded to full 808SA
memory
and I/O':
capability
The
7801
STO BUS interface may be
disabled
for
OMA •
FEATURES
• 80SSA
Processor
• 4096 bytes RAM
capacity
onboard
• 1024 bytes RAM
included
(211
4L
type)
• 8192 bytes ROM
capacity
onboard
(2716
type)
• 3 State Address, Data,
Control
Buses
•
• Power-on·reset
or
pushbutton
reset
input
• Five
interrupts
• Serial
1/0
lines
•
All
lC~s.-socket.ct
•
Single
+5V
operation
.7801:
6_25
MHz
crystal,
320ns time
states
.7801-1:
6_
144MHz
crystal,
325.5ns time
states
•
External
clock
input
option
..
M.RO-
INTRa"
IUMO-
WAITRO'
CNTRl.
(IXT CLKI
J1
INTIRRUPT
AND SIR.AL.
',0
ACCESS
",OCIISOR
IOI5A
DATA
IUS
ADORIIS
loSTATI
IUS
IU,.,'RS
loSTATt
IUS
IU"U
,.
7101
SHADING INOICATIS SOCKETS
ONU
'INDICATES ACTIVI
LOW
l.OGIC
FIGURE
ONE:
7801
BLOCK
DIAGRAM
DATA
IUS
(00007)
AOORISS
IUS
(AOoA1S'
~l..o<!.\IC."
MIMRO-
lORa-
WR'
MCSYNC-
INTAK'
IIUSAIC'
STATUS
O'
STATUS
l'
STSRn_TO
M'MlX'
10UIt·
I
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I
10
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II
PRO-LOG
CORPORATION A
REV
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SHT
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OF
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FOAM
NO. 101905