Studer A729 Bedienungsanleitung Seite 108

STUDER 4729
The LEDs give a fast indication about the
BUS CONTROLLER state. They supply
the
following information:
I
I
I
Select
Poll
Break
NAKfrom
VMa
NAKfrom
VCT
ERROR from VMa
ERROR
from
VCT
SCC
error
I
I
I
I
a
The EPROM is selected by
the address 415 inverted
line,
thus the EPROM range
is
8000
to
FFFF Hex.
The SCC's select signal is generated by the lC
131 which
decodes the address range
6000
to
TFFF Hex and
the
RAM
is selected for
the
address range 4000
to
SFFF Hex.
Address Decoding
4.3.3 ESTRIB
M
icro-processor System
The ESTRIB is
composed by the following
items:
'
HD 63A03
RP,
B-bit CMOS
micro-processor
r
an EPROM of
I
kBytes
r
an address bus demultiplexer
r
an address
decode circuit
and
it
can communicate with the
CONTROL
processor
directly through
a 7
bit
interconnecting bus (see
chapter 4.8).
The processor operates
in
multiplexed mode (MODE
2), (with internal
RAM,
without internal ROM). No external RAM is
provided.
The crystal frequency is fixed
to
4.9152 MHz
and is generated by the
CONTROL
processor.
The RD and WR
signals
are generated by three
NAND
gates
(lC
110) which
decode the R/W signal with the
E
clock.
There
are
three
l/Os
for the
ESTRIB
processor
:
'
the
SCC
r
the DIL-switches
r
the CONTROL processor
(NMl)
t/o
E 414
EDITION: 9. f,4äz 19s0