Modular computer system with portable travel unit

A computer system comprises a generally U-shaped base unit (10) and a generally-rectangular travel unit (12) which mates with the base unit, between the legs (34, 36) of the "U". The portable unit contains a complete computer system, including a flip-up monitor screen (14), a disc drive (20), and a detachable keyboard (24). The mating base unit includes expansion slots (30) for additional memory, peripheral equipment controllers, a CRT controller, etc. Also the base unit includes a controller (112) for one or more additional disc drives (26, 28). The facing sides of the legs of the U-shaped base unit have a step-shaped configuration (42, 44, 46) and the portable unit fits onto the step. The bight portion (38) of the base unit has a front connector (49A) for mating with the portable unit and rear connectors (48, 58A) for connection of additional equipment, such as a printer and modem.

BACKGROUND--FIELD OF INVENTION 
This invention relates to computers, particularly to a computer system 
having modular components, including a portable unit (for use when 
travelling) and a mating base expansion unit (for use in the office). 
BACKGROUND--DESCRIPTION OF PRIOR ART 
Popular computers for home and small-business use are usually termed 
micro-computers. Originally, and most popularly, such computers were 
desktop units consisting of the following components: a central processing 
unit (CPU), a display screen or monitor (usually a cathode-ray tube 
[CRT]), one or two disc drives, and a keyboard. The various components 
were usually provided in one or more interconnected components or boxes, 
e.g., with the CPU and disc drives in one box, the CRT in a second box, 
and the keyboard in a third box; or the CRT, CPU, and disc drives in one 
box and the keyboard in another box; or the CRT and CPU in one box, the 
disc drives in a second box, and the keyboard in a third box. 
While such units worked well, they were large, bulky, heavy, and awkward; 
thus moving them from one place to another was difficult and portable use 
was out of the question. I.e., they did not complement the work habits of 
business people, who travel frequently. 
In an attempt to remedy the above problems, several manufacturers have 
brought out so called "portable" computers. These comprised a 
suitcase-like enclosure which contained all of the components (CPU, CRT, 
disc drives, and keyboard) of a computer. While termed "portable" 
computers, these units were, in reality, difficult to transport readily 
because their size and bulk (about 25 to 35 liters and 9 to 14 kg) were 
too great for carrying, except by the most hardy individuals, and too 
great for ease of portable use, in, e.g., airplanes and other forms of 
transportation. They were especially too large to fit under an airplane's 
seat. In addition they required relatively high power and high voltage to 
operate, thus necessitating that they be used near an electrical wall 
outlet. 
While some portable computers were battery powered, their use has thus far 
been very limited because they had a relatively small memory, little or no 
capability for expansion, little or no capability for addition of bulk 
storage units, such as hard-disc drives, etc. Also they were heavy and 
bulky and were usually incompatible with regular office computers. Thus 
upon a return to the office, the user was faced with great difficulties in 
transferring data and programs to whatever larger computers such user's 
office had in use. 
OBJECTS AND ADVANTAGES 
Accordingly, several objects and advantages of the invention are to provide 
a new and improved computer, to provide a portable computer which is 
readily compatible with office machines and which can be used and expanded 
at the office, to provide a computer system which can readily fulfill a 
travelling businessperson's needs, to provide a portable computer which is 
light in weight, compact, and useable without access to wall outlets. 
Other objects and advantages are to provide a new modular computer design 
which is highly functional and useful, efficient in the use of space, and 
has a high degree of ergonomic (human engineered) compatability. Further 
objects and advantages will become apparent from a consideration of the 
ensuing description and accompanying drawings.

DRAWING REFERENCE NUMERALS 
______________________________________ 
10 base unit 11 space 
12 portable unit 14 monitor (flat display) 
16 screen 18 flat cable 
20 disc drive 22 power switch 
24 keyboard 26 front disc drive 
28 side disc drives 
30 expansion slots 
32 cover 34 right arm 
36 left arm 38 bight portion 
40 connector 42 base portion of 36 
44 top portion of 36 
46 ledge 
48 modem jack 50 AC power input 
51 AC power output (for 
52 DIN connector 
CRT) 
54 cable 55 groove 
58 rear connectors 60 switch 
62 central processing unit 
64 DMA channel 
66 interrupt unit 68 timer 
70 speaker driver 72 speaker 
74 ROM 76 RAM 
78 Parallel Port Interface 
80 printer controller 
82 EPROM 84 asynchronous comm unit 
86 LCD controller 88 modem 
90 controller 92 system buss 
94 battery and charger 
95 recharger plug 
96 low-batt. ind. 97 power on indicator 
98 disc drive port 100 hard disc drive port 
102 PCB 104 modem 
106 CRT controller 108 CRT port 
110 optional CRT 112 disc drive controller 
114 disc drive ports 
116 power supply 
118 asych. comm. unit 
120 printer controller 
122 connector 124 connector 
______________________________________ 
DESCRIPTION--FIG. 1--COMPUTER ARRANGED FOR OFFICE USE 
FIG. 1 is a perspective view taken from the front right side of the 
computer of the invention, arranged for office use. It comprises a 
U-shaped base unit 10 and a mating portable or travel unit 12. Travel unit 
12 is plugged into base unit 10 so that the base unit expands and enhances 
the capabilities of the travel unit. 
Travel unit 12 has a fold-up viewing screen or monitor 14 which has an LCD 
or other type of flat display screen 16. Screen 16 may have 25 lines of 80 
characters each and detent latches (not shown) to hold it in either its 
closed or upright position. Monitor 14 is electrically connected to unit 
12 by a flat cable 18. For semi-permanent storage, unit 12 has a removable 
disc drive unit 20, preferably of the type that uses a 3.5" (9 cm) floppy 
disc (preferably 700 kilobytes) or a hard (Winchester) disc (20 megabytes 
minimum) and a power switch 22 on its front. Unit 12 also has its own 
power supply in the form of a battery pack (now shown, but under keyboard 
24), together with an electronic computer system (not shown, but behind 
disc drive 20 and the battery pack) consisting of a CPU (central 
processing unit), RAM (Read-And-write Memory) chips for temporary working 
storage, ROM (Read-Only Memory) chips for permanently storing system 
programs (DOS and BASIC), I/O (Input/Output equipment) controllers, and 
other components, to be discussed later. Lastly, unit 12 has a detachable 
keyboard 24 which is positioned on the deck (FIG. 5) of unit 12. 
Base unit 10 has two disc drives 26 facing and accessible from the front 
(one is shown removed) and optional additional disc drives 28 on its right 
side. Preferably one of drives 26 may be a hard (Winchester) disc drive 
for high (multi-megabyte) storage capacity. Optional side disc drives are 
accessed by a fold-down cover 32 which snaps in closed position or is held 
by screw fasteners. Unit 20 also has its own electronic components (not 
shown, but in left arm 36 and bight portion 38) consisting of an AC-to-DC 
converter (power supply), expansion slots, and appropriate ports for a CRT 
monitor, additional hard- and soft-disc drives, etc., to be discussed 
later. Base unit 10 also has an on-off switch 60. 
When portable unit 12 is mated with base unit 10, a narrow space 11 will 
exist under the portable unit, but otherwise the mated units will have a 
rectangular compact configuration when the monitor is folded down or 
closed. 
As a brief introduction to its use and advantages, portable unit 12 can be 
removed from base unit 10 and carried about as needed and used wherever 
desired due to its own internal power supply, preferably a rechargeable 
battery pack. Since it has its own disc drive 20, it can be used to run 
any program desired. It can be conveniently carried by a (not shown but 
which can be a pull-out handle mounted on the front under the keyboard or 
underneath and arranged to swing up front) and when in use, screen 16 is 
unfolded to the position shown in FIG. 1 so that it can be used on one's 
lap in an airplane, or on a desk in a hotel or branch office, etc. 
DESCRIPTION--FIG. 2--REAR VIEW WITH PORTABLE UNIT TIALLY SEATED 
The computer system is shown in FIG. 2 with portable unit 12 partially 
removed from base unit 10. As indicated, unit 10 has a U-shaped 
configuration and consists of a right arm 34 (seen from the front), a left 
arm 36, and a bight or joinder section 38 which interconnects the rear 
ends of the two arms and contains one-half 40A of a connector for 
electrically connecting base unit 10 to a mating connector 40B on portable 
unit 12. 
Inside base unit 10 is a set of expansion slots 30. Printed circuit cards 
(not shown) can be plugged into these slots to provide various expansion 
functions known in the art, such as a modem, color controller, etc. These 
slots are accessed by removing the back panel of bight portion 38. 
At the rear of base unit 10 are a pair of female connectors 58A for 
supplying serial and parallel outputs. Into connectors 58A are plugged a 
pair of mating male connectors 58B which have cables which lead to a 
printer (parallel Centronics or equivalent brand) and an asychronous 
serial communications (RS-232) device, respectively. Additional jacks can 
be provided for other functions, such as a serial printer, machine input, 
etc. Another pair of jacks 48 are provided for connection to one or more 
external modems (1200 and 300 baud), if desired. Lastly, a power input 50 
is provided for receiving a power cord (not shown) and an AC power output 
51 is provided for supplying AC power to a a peripheral device, such as a 
CRT or printer. 
DESCRIPTION--FIG. 3--REAR VIEW OF SYSTEM 
The position of the portable unit in the base unit, the expansion slots in 
the base unit, the rear jacks, etc. are shown in the rear, elevational 
view of FIG. 3. Note that the back of the system is flat and vertical and 
the entire system assumes a compact, neat, and flat configuration, even 
when base expansion unit 10 is mated with the travel unit. 
DESCRIPTION--FIG. 4--OFFICE CONFIGURATION WITH KEYBOARD DETACHED 
The computer is shown in FIG. 4 in working (office or desk) condition. 
Keyboard 24 is detached for ease of use and monitor 14 is opened for 
viewing. Keyboard 24 has a full set of conventional computer keys and a 
coiled keyboard cable 54 which extends from a DIN connector 57 in a 
vertical rear wall of the portable unit under the monitor's hinge. Cable 
54 may alternatively be non-coiled and on an automatic retractor so that 
it will drawn back into unit 10 when keyboard 24 is replaced to the 
position shown in FIG. 1, Of course keyboard 24 can be removed from 
portable unit 12 whether or not it is mated with base unit 10 and keyboard 
24 can be used when it is in position on unit 12 as shown in FIG. 1. 
The base unit with the portable unit attached can be set back at the rear 
of a desk or on a table (not shown) and the keyboard can be placed at the 
front edge of a desk or on a typing table for ease of use. The system in 
this configuration has maximum capabilities and is the full equivalent of 
any desk computer. 
FIG. 5--PORTABLE UNIT IN USE 
A view of the portable unit in use with the keyboard detached and the 
screen open is shown in FIG. 5. Since portable unit 10 is light in weight 
and compact, and since it has its own power supply, its user can 
conveniently carry it to business conferences, on trips (domestic and 
international), and can used it in almost any form of transportation, such 
as in planes, boats, automobiles, a waiting room, lounge, etc. Thus it is 
most suitable for travelling personnel, such as salespersons, writers, 
etc. Due to its compact, loose-leaf book size, it can be stored in any 
briefcase. Since it is small and has a monitor which consumes low energy, 
it can use a small battery and thus does not need to be plugged into a 
wall outlet and can be carried easily, even by weaker individuals. 
To use the portable unit, the user need merely open screen 14 as indicated 
in FIG. 5. If space is relatively tight, as on a plane, keyboard 24 can be 
left in position as in FIG. 1 and the unit can be used on the lap or on an 
airplane serving tray. If more room is available, as in an office where a 
table and desk are available, keyboard 24 can be removed from the rest of 
portable unit 12 as indicated in FIG. 5 and used close to the user, e.g., 
on the lap or at the edge of the table closest to the user. Alternatively, 
any suitable form of wireless communication to the keyboard can be used, 
such as infrared, ultrasonic, radio waves, etc. 
Its size is approximately 6.3 cm thick, 21.5 cm wide, and 28 cm deep and it 
weighs only about 4 kg. Its keyboard 24 is held in position on the deck of 
unit 12 by a transverse groove 55 such deck and a mating rib (not shown) 
on the bottom of the keyboard. When cover 14 is closed, it is held closed 
by manually-closeable latches or detent latches (not shown), which may be 
integral with the cover and deck of unit 12. Cover 14, when latched 
closed, also holds keyboard 24 in position. 
FIG. 6--FRONT PERSPECTIVE VIEW WITH SCREEN AND KEYBOARD CLOSED 
As shown in FIG. 6, left and right arms 34 and 36 each have a step-shaped 
configuration when seen from the front. I.e., looking at left arm 36, it 
has a slightly wider base portion 42 and a narrower top portion 44 
positioned to the outside of the base portion so that a step or ledge 46 
is on the inside of the "U". Ledge 46 ends at bight portion 38 at the rear 
of the arm. The front surface of bight portion 38 is vertical and flat, 
save for connector half 40A. 
Portable unit 12 has an rectangular configuration. When the portable unit 
is mated or docked with the base unit, it fits onto ledges 46 and between 
top portions 44; its width is slightly less than the spacing between top 
portions 44 as indicated by the broken assembly lines. When the portable 
unit is positioned on the base unit in this manner, its connector 40B 
(FIG. 2) mates with connector 40A on the base unit; ledge 46 assures 
correct vertical positioning. A pair of snap-in detent latches (not shown) 
on the inner sides of arms 34 and 36 of the base unit mate with 
corresponding latches (not shown) on the sides of the portable unit to 
assist in holding the two units securely together; when the portable unit 
is to be removed, it is pulled out with sufficient force to break the hold 
of the latches. 
DESCRIPTION--FIGS. 7A AND 7B--ELECTRONIC BLOCK DIAGRAM 
FIGS. 7A and 7B is a block diagram of the electronic components of the 
computer system. The electronic components within the travel unit are 
shown in FIG. 7A and those in the base unit are shown in FIG. 7B. First, 
the components already mentioned will be discussed. 
In FIG. 7A, the keyboard and its cable are shown at 24 and 54, 
respectively, while the LCD display and its cable are shown at 14 and 18, 
respectively. The connectors which interconnect the portable and base 
units are shown at 40A (FIG. 7B) and 40B. The power switch on the travel 
unit is shown at 22, while the rear connectors are shown at 58A. 
All of the components of a conventional computer are provided in the travel 
unit, including a central processing unit 62, a DMA (direct memory access) 
channel 64, an interrupt unit 66, a timer 68, a speaker driver 70, a 
speaker or other transducer 72, a ROM 74 (ROM 74 includes the BIOS [Basic 
Input-Output System] for the computer), a RAM 76 (capable of storing 256 
or more kilobytes), a Parallel Port Interface (PPI) 78 (connected to 
keyboard cable 54 via a DIN connector 52), a printer controller 80 
(connected to the printer cable by a Centronics or equivalent brand 
connector 58A), an Eraseable Programmable ROM (EPROM) 82, an asynchronous 
communications unit 84 (optional, but preferably a type 8250 chip), an LCD 
controller 86, a modem 88 (300/1200 baud), and a controller 90 for 3.5" 
5.25" floppy disc drives and a hard disc drive. All of these components 
are joined by a system buss 92 which is also connected to connector 40B 
for connection to base unit 10. Various other conventional components and 
interconnections, well known to those skilled in the art, are provided, 
but are not shown for purposes of clarity and brevity. 
Portable unit 12 also includes a battery and charging unit 94 which has its 
own recharger plug 95 (not shown, but which is preferably on the rear of 
the device) for recharging and a low battery indicator 96, adjacent plug 
95. A power-on indicator 97 can also optionally be provided. LCD 
controller 86 is also connected to and drives display monitor 14 via cable 
18. Disc controller 90 is connected to 3.5" disc drive 20 and also can be 
connected to 5.25" and hard disc drives via symbolically-illustrated ports 
98 and 100 which are not shown on the outside of the portable unit, but 
which can also be provided on its back surface. Printer controller 80 is 
connected a printer output terminal (part of connector 58A), and 
asynchronous communications unit 84 and printer controller 80 are 
connected to their output terminals, also part of connector 58A. 
All of the components just discussed, except for the connectors, 
indicators, and battery unit, are mounted on a Printed Circuit Board (PCB) 
102 which is provided in the bottom of the base unit (FIG. 2), to the rear 
of disc drive 20. The battery unit is also provided in the bottom, to the 
left of disc drive 20. 
The components in unit 10 serve to expand the capabilities and functions of 
the portable unit. To this end unit 10 includes up to five expansion slots 
30 which are connected to buss 92. These comprise a row of PCB cardedge 
connectors, e.g. of the type shown in Sochor U.S. Pat. No. 4,275,944 
(1981), for receiving optional printed circuit cards (not shown) which can 
be plugged into the connectors to add various functions to the computer, 
such as additional memory, i.e., additional RAM capacity, a graphics 
controller, network controller, an IEEE-488 instrument controller buss, a 
plotter controller, etc. Also connected to buss 92 is a CRT controller 106 
for monochrome or color CRT displays, as indicated. Controller 106 is also 
connected to a CRT port 108 to which an optional CRT 110 can be connected. 
As is known, it is desirable to use CRT 110 in lieu of a flat screen LCD 
monitor 14 in certain applications, e.g., where a full-page display is 
desired, where higher resolution is desired, etc. Also a disc drive 
controller 112, similar to controller 90 of travel unit 12, is provided 
for two additional optional side disc drives 28 (FIG. 1) on the side of 
the base unit. These may be a 5.25" drive and/or a 3.5" drive as shown, or 
one may be a hard disc drive, as indicated. 
The base unit also contains a power supply 116 which is connected to an AC 
cord 50 and which converts the alternating current mains power to suitable 
DC voltages for driving the electronic components of the computer. Power 
supply 116 preferably is a 220-watt supply or a 100-watt supply which can 
be expanded by add-on 60-watt expansion modules. Base unit 10 may also 
contain optional additional units, such as an asychronous communications 
unit 118 and a printer controller 120; these units are connected to 
respective ports or connectors 122 and 124 on the outside of the unit. A 
modem 104 (300 and 1200 baud) is provided for allowing the computer to 
communicate over telephone lines; the modem has its own connectors or 
ports 48. All of the components are mounted on or adjacent a PCB 
(motherboard) 126. 
In the base unit, PCB 126 (which has expansion slots 30 mounted thereon) is 
provided in left arm 36 (FIG. 2) while power supply 116 is provided in 
bight portion 38. Alternatively, the power supply can be provided in the 
left arm, at the front, and the PCB can be provided in the rear of the 
left arm or in the bight portion. 
OPERATION 
As discussed, portable unit 12 is a complete computer in itself, so that it 
can be used for most computing functions, especially by a business 
traveller. When the user is at home or a branch office, he or she can 
expand the portable unit by mating it with the base unit, whereupon he or 
she will enjoy additional internal memory for handling large accounting 
tasks, large word processing tasks, etc. Also the user will be able to 
perform additional functions, such as instrument control, control of large 
printers, networking functions, control of mechanical systems, control of 
graphics plotters, etc. if the necessary PCB expansion cards have been 
plugged into the expansion slots. As also indicated, the physical 
arrangement of the portable and mating base units are highly complimentary 
so that the complete system is compact and the expanded features are 
convenient to the user, at the front or sides of the machine. 
SUMMARY, RAMIFICATIONS, AND SCOPE 
Accordingly, it is seen that, according to the invention, a highly useful, 
versatile, modular computer system is provided which has the full 
capabilities of a desktop computer yet which can be used easily in the 
field or when travelling. 
While the above description contains many specificities, these should not 
be construed as limitations on the scope of the invention, but as 
exemplifications of the presently-preferred embodiments thereof. Many 
other ramifications and variations are possible within the teachings of 
the invention. For example, fewer components than those shown can be 
provided in the portable unit if additional compactness and less weight is 
desired. The portable unit can be made to share the base unit's power 
supply. The base unit can have a built-in full page display monitor, 
printer, etc. The semi-permanent memories (RAM) on the portable or base 
units can be bubble memories, semiconductor storage memories, etc. in lieu 
of disc drives, etc. The base and portable unit's power supplies can be 
arranged to be interconnected via connectors 40A and 40B such that when 
the portable unit is plugged into the base unit and the base unit is 
turned on, the portable unit will also be turned on and will draw its 
power from the base unit, thereby to conserve its battery. When the base 
and travel units are connected via connectors 40A and 40B, the base unit's 
power supply will recharge the travel unit's batteries, even if the base 
unit is turned off. Thus the scope of the invention should be determined 
by the appended claims and their legal equivalents, and not by the 
examples given.