The Zcb As Part Of A System; Cpu Section - Vector ZCB User Manual

Vector
ZCB
Single Board Computer
I. PERSPECrIVE
1.1 The
ZCB
as a system
The Vector Graphic
ZCB
Single Board Computer provides the capability of a
ccrnplete canputer system on a single board. The
ZCB
contains what you WJuld
normally find on a CPU board, a PROM/RAM board and an I/O board, all
contained on one S-lOO bus canpatible board.
The ZCB contains a Z-80A microprocessor, 1024 bytes of static
RAM
memory,
sockets for up
to
12K of PRCM, one serial I/O port and three 8-bit parallel
ports. Circuitry is provided to support static or dynamic memories. All
S-lOO 8080 signals are also generated making the ZCB compatible with 8080
based systems. On-board power regulation and filtering is provided using IC
regulators
and
heat sinks for power dissipation. Input loading on the bus is
1 low power
TTL
load while output fanout is 10
TTL
loads.
While the ZCB does replace 3 boards in a typical system, it is not a
complete stand alone microcanputer on one board. A terminal device of some
sort is needed as well as additional
RAM
memory, for rost applications. The
ZCB could, however, be used as a complete microcomputer in many process
control applications. In this case, preprogrammed PROMs (up to 12K bytes
worth) could be used on a
ZCB
board that was equipped with a power supply.
Sense data could arrive by an input parallel port,
be
processed by the CPU
section of the board and any data output (control signals, for instance)
could
be
camnunicated to the equipment via the output parallel port. The
data input and a summary of actions taken could be communicated to a central
data processing location by the serial port. Thus the ZCB might
be
used as
an intellegent node on a canplete process control system, which could decide
and provide output irmnediately and provide information to a higher level
data processing system.
1.
2 The ZCB as part of a system
In most applications, however, the ZCB will
be
used a part of a complete
Vector Graphic microcanputer system. Since
3
boards are replaced by one,
significant cost savings are realized. It also reduces the physical size of
the overall canputer that it is used with by freeing up two S-lOO slots.
Demands on the power supply are also reduced, thereby lightening the load on
the canplete system.
The ZCB combines the most used features of
3
boards: CPU board, PRCM/RAM
board and Serial/Parallel I/O board.
1.3 CPU section
The Vector Graphic ZCB is designed around the powerful Z-80A
microprocessor. The board is S-lOO bus canpatible. All input and output
lines are fully buffered. Loading on the bus is no more thail one standard
TTL
load. In addition, the board has the necessary circuitry to work with
Rev.
I-B
6/11/80
1-1