User port

Configuration/system testing (each user port tested for connection to network)... 

For some ports, the computer s operating system—the ROM which controls the machine s functions—provides routines that handle much or all of the "dirty work" of communicating with peripheral devices. To use other ports, you must program all the necessary support routines yourself. That task can range from very easy (for example, reading a joystick) to quite complex (interfacing with a parallel printer through the user port, for example). 

Obviously, this port is bidirectional—data can flow both in and out with equal ease. The signal format used to exchange data serially over the six lines provided through this port is unique to Commodore. The format should not be confused with the more standard RS-232 serial communications format used by numerous peripherals RS-232 communication is handled through the user port (see below). The serial port is essentially a stripped-down version of the parallel IEEE-488 port used for most data communications in Commodore s earlier PET/CBM models. As the term serial implies, data can be transferred only one bit at a time (and in only one direction at a time, either in or out). Three of the other lines control the direction of data flow, and whether the signals on the data line are to be interpreted as data or as commands to the peripheral device. The computer s RESET line is also present at this port, which explains why the disk drive resets whenever the computer is turned on or off. 

The Commodore 16 has no user port, so it is as yet unclear how (or if) a modem may be used with that computer. 

For more information on interfacing through the user port, see the article "Using the User Port" in COMPUTERS First Book of Commodore 64. 

Although the code is based on well-recognized models referenced in the literature, some of the underlying models are based on "older" theory which has since been improved. The code does not treat complex terrain or chemical reactivity other than ammonia and water. The chemical database in the code is a subset of the AIChE s DIPPR database. The user may not modify or supplement the database and a fee is charged for each chemical added to the standard database distributed with the code. The code costs 20,000 and requires a vendor supplied security key in the parallel port before use. 

The software is written in the C language on an Atari ST microcomputer (1) and utilizes a GEM graphics user interface which features mouse control, windows, pulldown menus, and pop up alert and data entry boxes. The system could be ported to the IBM PC under the GEM operating system if the need were to arise. 

Garramone, J.P (1986). Vascular Access Port Model SLA. User s Manual. Norfolk Medical Products, Skokie, IL. 

WAP. The WAP provides the wireless data communication service. It usually consists of a housing (which is constructed from plastic or metal depending on the environment it will be used in) containing a circuit board, flash memory that holds software, one of two external ports to connect to existing wired networks, a wireless radio transmitter/receiver, and one or more antenna connections. Typically, the WAP requires a one-time user configuration to allow the device to interact with the local area network (LAN). This configuration is usually done via a Web-driven software application which is accessed via a computer. 

From the general audience came this comment "Instruments today are not too compatible to transfer information. There is the RS-232 port with its 8-bit code and all sorts of hand shaking and lines to be hooked up properly. It is just difficult to set up. And as we have already said in this panel discussion, "There are not adequate conventions for data communication and transportability. I think that the answer to that is that the analytical chemist and these people who are interested in that sort of data exchange will have to become extremely active in this area to reflect the needs of the user. ... 

Port Selector Valve. The inside of the Model 50 Extractor oven was originally equipped with a VALCO 4-port selector valve (Model No. E04). This valve is important in operations regularly utilizing additional co-solvents, inerts or vacuum, as in the introduction of modifiers in our case. When the valve is mounted in its normal fashion, one inlet port controls the flow to four outlet ports which are user selected by position number. When the valve is mounted in a reverse fashion, four inlet ports control the flow to one outlet port. In this manner, the inlet ports can be used to independently deliver various solvents. This reverse configuration is used in our system design. With this configuration, multiple fluids can be introduced to the extraction vessels with ease. 

Sediment in rivers, streams, and lakes destroys aquatic habitats, decreases storage capacity of reservoirs, and interferes with navigational and recreational uses of water. The damage from sediments includes the loss of fish spawning sites, the cost of dredging ports and navigable rivers, and the cost of cleaning water for industrial and household users. 

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