Radio Shack Quick Printer II Technical Reference Manual

CARTRIDGE
ROM
AND OTHER
DEVICES
The 40-pin
cartridge
connector
provides the
possibility
of
expanding
the TRS-80
Color
Computer
in almost any
manner.
All of
the important
CPU bus
signals are
tied
to this
connector.
A
complete list
and brief
description of
these
signals
is provided
in Table
5.
The
most
common
usage of
the
cartridge
connector
is
with the
ROM Cartridge.
A schematic
of
the
ROM
Cartridge
board
is
shown
in Figure
15. In operation,
U1 would be
a 16K, 32K, or
64K ROM,
and U2 might
be a
16K
or
32K ROM
(the total of
U1 and
U2 must not
be
greater than
64K).
For cartridge
detection,
the clock
signal
(Q)
is
shorted
to
the cartridge
interrupt
pin. This generates
an
interrupt anytime
the
cartridge
is plugged
in
and forces the
computer
to jump
to the
program
in
ROM.
In addition
to the expected
data,
address,
and R/W
lines,
several
control
and special
purpose
signals are
available on the
Cartridge
connector.
They are
described in
detail
as follows:
HALT*
-
This signal allows
the data
and address
buses to
be
placed in the
tri-state
mode
so an external
processor
may
access
RAM and
ROM.
NMI*
-
This is the
non-maskable
interrupt
input to the
CPU.
RESET*
—
This
is master
system reset
and power-up
clear
signal.
E
& Q
—
These are the
two clock
signals for
the 6809E
CPU.
CART*
-
This is an interrupt
input
to one of
the PIA'S.
It is
used
to detect the
presence of
a Cartridge.
CTS*
—
This
is the select
signal
to the Cartridge.
The address
space C000 (Hex) through FFEF
(Hex) is selected.
SND
—
This signal
is connected
directly
to
the
sound
multiplexor,
to allow
a sound
source
in the cartridge.
SCS*
-
This is
a
spare divide
select
signal from
U11.
It
selects
the
address space FF40
(Hex) through
FF5F
(Hex).
SLENB*
—
This signal disables
the
internal device
selection.
This
allows decoded but
unused
sections of
memory
to be
used by the
Cartridge
hardware.
35

Radio Shack Quick Printer II Specifications

General

Brand	Radio Shack
Model	Quick Printer II
Category	Desktop
Language	English