Compaq 300 manual Alpha Buffers, ∙ Storing alpha values so that they can be read later

Models: 300

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Operation (Windows NT)

5.3.3.2 Performance Considerations

PowerStorm 300/350 PCI graphics controllers for the Windows NT Alpha platform accelerate virtually all OpenGL Version 1.1 operations. However, some aspects of OpenGL use can affect performance as described in the following sections.

5.3.3.2.1 Texture Mapping

Several aspects of texture mapping can affect application performance. Some of these are under the control of the application user. Others are under the control of the application developer.

When an application defines textures to OpenGL it can explicitly specify the resolution (for example 16 or 32 bits per texel) with which textures are to be stored. Alternatively, the application can leave this decision to OpenGL. In this latter case the PowerStorm 300/350 OpenGL driver will, by default, use 16 bits per texel for RGB and RGBA textures. The application user can override this default behavior by setting the Texel 32 Bit Default selection in the Display Applet.

Allocating 16 bits per texel allows more textures to be stored in the texture cache and may provide slightly higher rasterization rates. On the other hand, using 32 bits per texel provides better texture resolution in just the same way that a color frame buffer with 8 bits per color component has better color resolution than a frame buffer with 4 bits per color component.

The rasterization rate for PowerStorm 300/350 PCI graphics controllers is twice as fast for bilinear texture filtering as for trilinear texture filtering.

Software developers should use OpenGL Version 1.1 texture objects when an application has more than one texture.

5.3.3.2.2Alpha Buffers

PowerStorm 300/350 PCI graphics controllers on the Windows NT Alpha platform do not provide an alpha buffer (i.e., it has zero alpha planes). Few applications actually need an alpha buffer. The two operations that depend on the values stored in the alpha buffer are:

Storing alpha values so that they can be read later

The application needs an alpha buffer if it must store alpha values for later retrieval by the glReadPixels function with one of the following formats:

GL_ALPHA

GL_RGBA

GL_LUMINANCE_ALPHA

5–16PowerStorm 300 AGP and 300/350 PCI Graphics Controllers

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Compaq 300 manual Alpha Buffers, ∙ Storing alpha values so that they can be read later

300 specifications

The Compaq 300, introduced in the early 1990s, marked a pivotal moment in personal computing, combining cutting-edge technology with user-centric design. This desktop system was targeted at both business professionals and home users, reflecting the growing demand for powerful yet affordable computing solutions.

One of the main features of the Compaq 300 was its robust Intel processor. It originally shipped with various configurations of Intel's 80486 microprocessor, which provided a significant performance boost over its predecessors. The 486 architecture enabled users to run more complex applications, enhancing productivity and making it suitable for tasks ranging from word processing to graphics editing.

In terms of memory, the Compaq 300 supported up to 16MB of RAM, which was substantial for its time, allowing seamless multitasking of programs. The system typically included a 120MB IDE hard drive, which facilitated ample storage for documents and software, a critical aspect for users who needed to manage large volumes of data.

The Compaq 300 featured an integrated graphics card based on the popular VGA standard, enabling clear display quality for applications and gaming. Notably, its 14-inch CRT monitor that accompanied the system offered crisp visuals and an optimal viewing experience for users.

Another characteristic of the Compaq 300 was its expandability. The desktop came equipped with several expansion slots, allowing users to easily add components such as sound cards, network cards, or additional storage drives. This feature provided users with the flexibility to upgrade their systems as technology evolved, ensuring longevity in a rapidly changing landscape.

The Compaq 300 also showcased advanced connectivity options for its time. It included multiple serial and parallel ports, providing versatile connectivity with peripherals like printers, scanners, and modems. This adaptability was crucial, especially as businesses began to integrate more technology into their operations.

Durability and reliability were hallmarks of Compaq's design philosophy, and the Compaq 300 was no exception. Its solid construction and dependable components appealed to users who required a trustworthy system for daily tasks.

Overall, the Compaq 300 epitomized the intersection of performance, expandability, and reliability in desktop computing. Its innovative features and thoughtful design paved the way for future developments in the personal computer industry, making it a noteworthy entry in the history of computing technology.