Parallel port

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 transmission of data between an ADC or DAC and a computer is usually accomplished by sending one byte at a time along a multiway ribbon cable external bus). The IEEE 488 standard bus has been widely used for this purpose, but other buses are also used. As all bits are handled simultaneously this is known as parallel I/O transmission, the data entering or leaving the computer via a parallel port or by direct connection to the computer s internal bus. Alternatively, one bit at a time can be transmitted along a single line serial I/O transmission). Data enter or leave the computer via a serial port, usually an RS-232C. Serial I/O ports are used for... 

The actual mode of connection between instrument and computer varies depending on the type of signal generated and the design of the instrument. The connection can be made via a serial port, a parallel port, or a USB port. The electronic circuitry required is built into the instrument s internal readout electronics or into an external box used for conditioning the instrument s output signal. In some cases, the instrument will not operate without the computer connection and is switched on and off as the computer is switched on and off. In other cases, the entire computer is built into the instrument. 

Motorola introduced the 96002 [Sohie and Kloker, 1988] as an extension to the existing 56000 architecture. The instruction set is an extension of the 56000 instructions, adding floating point instructions and implementing the IEEE 754 floating point standard directly instead of converting to an internal format (like the DSP-32). It has two parallel ports for multiprocessing. 

Processor/memory symptoms Mouse Floppy drive Parallel ports Hard drives CD-ROM DVD... 

A video (9 female) 9 female with and parallel port a single RCA connector ... 

DB-25 25 sockets Female Most often a parallel port. On Macintoshes, however, this type of connector is used for the external SCSI bus. 

Iomega s Zip and Jaz drives are detachable, external hard disks that are used to store a large volume (around 100MB for the Zip, 1 and 2GB for the Jaz) of data on a single, floppy-sized disk. The drives connect to either a parallel port or a special interface card. The major use of Zip and Jaz drives is for transporting large amounts of data from place to place. This used to be accomplished with several floppies. 

The most common use of the parallel interface is printer communication, and there are three major types standard, bidirectional, and enhanced parallel ports. Let s look at the differences between the three. 

The standard parallel port is a parallel port that only transmits data OUT of the computer. It cannot receive data (except for a single wire carrying a Ready signal). This is the parallel port that came with the original IBM PC, XT, and AT. This port can transmit data at 150KB/second and is commonly used to transmit data to printers. This technology also has a maximum transmission distance of 10 feet. 

As its name suggests, the bidirectional parallel port has one important advantage over standard parallel ports it can both transmit and receive data. These parallel ports are capable of interfacing with devices like external CD-ROM drives and external parallel port backup drives (Zip, Jaz, and tape drives). Most computers made since 1994 have a bidirectional parallel port. 

There are two implementations of IEEE 1284, ECP parallel ports and EPP parallel ports. An Enhanced Capabilities Port (ECP port) was designed to transfer data at high speeds to printers. It uses a DMA channel and a buffer to increase printing performance. An Enhanced Parallel Port (EPP port) increases bidirectional throughput from 150KBps to anywhere from hOOKBps to 1.5MBps. 

If you wanted to connect a LapLink cable (a parallel data transfer cable) so that you could upload and download files from a computer, which type of parallel port(s) does your computer need to have ... 

B, C, D. Bidirectional parallel port can both transmit and receive data. An ECP was designed to transfer data at high speeds. EPP parallel ports provide for greater transfer speeds and the ability to send memory addresses as well as data through a parallel port. 

C. The 1394 standard provided for greater data transfer speeds and the ability to send memory addresses as well as data through a parallel port. 

D. IEEE 1284 standard defines the ECP parallel port to use a DMA channel and the buffer to be able to transfer data at high speeds to printers. 

In addition, because the controller was integrated into the same assembly as the drive, the only board that needed to be installed in the computer was an adapter that converted signals between the motherboard and the drive/control-ler. The board is normally called a pass-through or paddle board. (This board is often, incorrectly, called a controller. The term is incorrect because the paddle board is often integrated with a floppy controller, two serial ports, a game port, and a parallel port. In fact, this combination is normally called a multifunction interface board.) With some of today s systems, the IDE adapter is integrated into the motherboard. 

They usually use a COM port or bidirectional parallel port instead of SCSI to transfer their data. They are limited in their quality, however, and generally should not be used in graphics work. 

There are several components to an interface, including its communication type as well as the interface software. Each aspect must be matched on both the printer and the computer. For example, an HP LaserJet 4L only has a parallel port. Therefore, you must use a parallel cable as well as the correct software for the platform being used (e.g., a Macintosh HP LaserJet 4L driver if you connect it to a Macintosh computer). 

Printer parallel port—Uni., bidirectional, disable/enable, ECP, EPP... 

With some of the newer computers, several components are integrated onto the motherboard. If you troubleshoot the computer and find a hardware component to be bad, there s a good chance that the bad component is integrated into the motherboard (for example, the parallel port circuitry) and the whole motherboard must be replaced. An expensive proposition, to be sure. 

The next most popular peripheral connection method is parallel. Parallel connections transfer data 8 bits at a time as opposed to 1 bit at a time (as serial connections do). The most common peripheral connected via a parallel connection is a printer. Hence, parallel ports are often called printer ports. Additionally, newer parallel ports can connect devices like scanners and Zip drives to computers. Unfortunately, this doesn t work as well as other types of connection methods such as USB work because the parallel connection wasn t designed for connecting devices other than printing devices. Parallel was only designed to connect one peripheral at a time. 

The wizard will ask you a series of questions that will help you to configure the printer. The first question it will ask you is Do you print from MS-DOS-based programs The reasoning behind this question is similar to the reason we map drive letters. Most older DOS programs (and to a lesser extent, Windows programs) don t understand the UNO path syntax for access to a shared resource. Instead, they understand a name for a local hardware resource (like LPTl, for the first local parallel port). So, you must point a local printer port name out to the network in a process known as capturing. If you need to capture a printer port, answer Yes ... 

A, B, C. Parallel connections have a transfer rate of 8 data bits, they are primarily used to connect printers, and new parallel ports can connect other devices. However, they can connect only one device at a time. 

With Windows 9x, Microsoft provides the Device Manager, a tool that will analyze hardware-related problems. The Device Manager displays all of the devices installed in a computer (as shown in Figure 19.1). If a device is malfunctioning, a yellow triangle with an exclamation point inside it is displayed (as with the Iomega Parallel Port Interface in Figure 19.1). 

LPTx ports In DOS, the device name used to denote a parallel communications port, often used with a printer. DOS supports three parallel ports LPTl, LPT2, and LPT3, and OS/2 adds support for network ports LPT4 through LPT9. 

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