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Cub Workstation Design Goals
Provide a low cost "front end" for the OIS
market
1. Provide an imaginal display
2. Provide Ethernet connection
3. Provide personal services (text/graphics)
4. Not to provide all services in the terminal
(reach th rough)
cub-goats. bravo
A Discussion of Cub Architecture and
A Discussion of Cub UMC estimates
May 23, 1980 R. Belleville filed on cub-may80.bravo
What is a Cub?
Cub is a new workstation under development in SDD. The purpose of the design is to provide a
truly Ethernet compatible, low-cost workstation for the mainstream of the office automation market.
Cub users have at their fingertips, not only a powerful personal computer, but also network access
to servers and resources on the Ethernet.
Cub provides an 8086 based process~r running at 4.5 MHz. This is a 16 bit microprocessor with a
full range of instructions and addressing modes. Main memory consists of 262.144 bytes (8 bits data
plus 1 bit parity) of dynamic random access memory. Single bit memory errors are detected by a
parity system. A bank of up to 16,384 bytes of read only memory are also provided for "bootstrap"
program storage. Main memory is refreshed automatically.
A full page, bitmap display is also part of the Cub workstation. An image 606 bits wide by 808 bits
high is displayed on a 15 inch video monitor. The frame buffer storing these 489,648 bits is also
implemented with dynamic ram and does not use any processor main memory. In all, Cub has
320K bytes of ram.
The display controller also includes a 16 x 16 bit cursor which is "ored" into the image at the x and
y coordinate provided by software. Separate storage is provided for the cursor bitmap in a 16 word
ram associated with the display controller.
Input/Output controllers are provided for the keyboard, mouse, and a single channel RS-232 serial
interface. The serial interface can operate at speeds from 300 to 9600 baud. An 8 channel,
vectored interrupt system is also included with the processor. Interrupt based service is provided for
the serial interface, keyboard, real-time clock, network interface, and main memory parity error
detection.
An Ethernet controller is also an integral part of Cub. The interface can send or receive packets of
data, to or from main memory at speeds from 3 to 10 Mbps. Transfers are under direct memory
access control, and do not require the processor during data transfer.
Cub has little "built in" functionality. All application software is "downloaded" from a server via
the Ethernet. Data files created by the user are communicated to servers for storage and retreival
via the Ethernet. Cub provides for no fixed or removable storage at the workstation. This
approach allows the use of cost effective mass storage at the server, and frees the workstation from
the cost, noise, and reliability problems of rotating storage.
Details of the organization of Cub are shown in the block diagrams below.
How can Cub be useful without a disk?
I
By itself, a Cub ~ useless. It depends on the Ethernet to communicate with servers located on the
network.
The first dependency is for program loading. After powerup, Cub sends a message on the Ethernet
which asks for