Abstract: The present invention presents a process of moving an array of pixel data representing an image to be displayed from a source memory space to a destination memory space. The array of pixel data is arranged in words containing a plurality of individual pixel datum. The process includes transforming each pixel datum in the word fetched from the source memory space to a colorized pixel datum by individually attaching color information to each pixel datum. The transforming occurs substantially in parallel on all of the pixel data in each word. This technique permits storage of commonly used images such as alphanumeric characters of various fonts or icons in a compressed form with one bit per pixel. These images are formed in color using the color expand operation at the time of drawing into the color display memory. Otherwise these images would need to be stored in multiple bit per pixel color form for all desired colors requiring considerable memory for redundant data.

Abstract: A graphics processor device performs bit-by-bit masking outside of the central processing unit, by way of a read-modify-write cycle to external or internal memory. A mask bus is incorporated into the device so that, for each bit of the external data word, a mask bit is present which indicates whether data from the central processing unit (CPU) is to be written to memory (unmasked) or if that bit of memory contents is to remain unaltered (masked). The CPU data is written into a latch at the memory interface during such time as the latch is isolated from the external memory bus and during the read portion of the read-modify-write cycle. For those bits which are to be masked, the latch is overwritten with the data read from memory, while for the unmasked bits the latch remains isolated from the external memory bus. During the write portion of the read-modify-write cycle, the contents of the latch are driven onto the external memory bus.

Abstract: A monochrome image becomes expanded into a color image for storage in a bit mapped color display memory. The color expand operation substitutes color data of one of two designated colors for the "1" or "0" monochrome data of a stored monochrome image. The first color code is substituted for all pixels of the monochrome image represented by a "1" and the second color code is substituted for all pixels of the monochrome image represented by a "0". This color expanded image is then stored in the color display memory which controls the color picture shown to the user. This technique permits storage of commonly used images such as alphanumeric characters of various fonts or icons in a compressed form with one bit per pixel. These images are formed in color using the color expand operation at the time of drawing into the color display memory. Otherwise these images would need to be stored in multiple bit per pixel color form for all desired colors requiring considerable memory for redundant data.

Abstract: A graphics processor device is disclosed which performs bit-by-bit masking outside of the central processing unit, by way of a read-modify-write cycle to external or internal memory. A mask bus is incorporated into the device so that, for each bit of the external data word, a mask bit is present which indicates whether data from the central processing unit (CPU) is to be written to memory (unmasked) or if that bit of memory contents is to remain unaltered (masked). The CPU data is written into a latch at the memory interface during such time as the latch is isolated from the external memory bus and during the read portion of the read-modify-write cycle. For those bits which are to be masked, the latch is overwritten with the data read from memory, while for the unmasked bits the latch remains isolated from the external memory bus. During the write portion of the read-modify-write cycle, the contents of the latch are driven onto the external memory bus.

Abstract: A graphics data processing apparatus having graphic image operations on two images. Two graphic images are formed into a single combined image based upon a predetermined combination of the multibit color codes representing corresponding pixels of the two images. A transparent color code is permitted for the first of the graphic images. The combination of a transparent color code from the first graphic image with any color code from the second graphic image yields the color code of the second graphic image. This innovation enables the use of color codes having selectable numbers of bits set by the number stored in a pixel size register. In particular the transparent color code, which is detected by a transparent color code detection device independent of the image operation, has a selectable number of bits set by the pixel size register in a manner like any other color code.

Abstract: A digital processing system includes an external memory for the storage of program instructions for use with a separate processor that internally contains a memory for temporary storage, an arithmetic and logic means, a register set, control and timing circuitry, and two sets of data paths. The first set of data paths provide access to the external memory for transfer of instructions from the external memory to the processing unit. The second set of data paths provide for the internal routing of instructions data and addresses within the processor unit itself. The data structure for the first set of data paths is different than that for the second set of data paths, providing for an external data structure that is different than the internal data structure of the processor.

Abstract: A flexible catheter apparatus is adapted to be positioned in a patient for use in cardiac pacing, with a first electrode positioned within the heart, and a second one positioned outside the heart. In the preferred embodiment, the first electrode includes a plurality of spaced apart conducting bands located within about 2 cm of the end of the catheter. The bands are electrically connected and are two or more in number, with one such band located at about the distal end of the catheter, and at least another located about 1.0 cm from the distal end.