Vector 4 - Page 120

~ - | VECTOR 4
TECHNICAL INFORMATION
SECTION VI - OVERVIEW OF THE KEYBOARD
SYSTEM
Summary: The keyboard receives and transmits data serially. It is
attached to the face plate of the Vector 4 main chassis via a 3-foot
coiled signal/data cable with a plug-in telephone type jack.
A descmptlon of the interconnecting lines used in keyboard signal/data transmission
is given in Exhibits [I-27 and [I-28. As can be seen the Serial Out and Serial In
lines change notation when they reach the keyboard. This occurs because the
keyboard uses notation referring to ns_gnmux_and_mp_ul
A schematic of the keyboard is shown in Exhibit VI-10. The keyboard uses one
main circuit board which holds several components. The major components are
listed below:
1.
2.
3.
* %
*xkxk
91 high-capacitance keys.
One 8035 microprocessor located at Z3. This microprocessor provides the
intelligence for key decoding and serial transmission of data. It has a timer, 8
bi-directional data lines, 17 programmable port lines and several control lines.
This hardware allows the microprocessor to interface with the 2716 PROM,
decoder chips, and external connector.
Two decoder chips located at Z5 and Z4. These chips provide row and column
addresses for the individual keys. Their outputs are connected to the 8035s
P10-P17 program lines.
One 2716 PROM located at Z2. The PROM contains a keyset servicing program
along with complete look-up tables for each Hex encoded key. The physical
codes for all keys is shown in Exhibit II-29. These "physical" codes are sent to
the Vector 4 operating system (Standard: Extended CP/M) where they are
translated into Vector 3 compatible codes (See Exhibit II-30) These codes are
then routed (via Video Subsystem) to the character generators where they are
used to address particular characters.
The following table compares the Vector 3 compatible set with the physical hex
code representation.
Key Mcde Y-3 Compat. Set Physical Set
1 ** Unshift 31 31
1 *** Unshift 31 81
1 Unshift 15 8A
Located on standard portion of keyboard.
Located on "number pad".
09-01-82 7200-0001 II 6-1