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Generalized Pattern Transfer from Storage to Storage Bit Buffer

IP.com Disclosure Number: IPCOM000050028D
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 3 page(s) / 72K

Publishing Venue

IBM

Related People

Evangelisti, CJ: AUTHOR [+2]

Abstract

A method is described herein for transferring pattern data from a host array to a display bit buffer with windowing. The method includes a provision for rapid transfer of an arbitrary bit pattern from part of one storage array to another storage as required in various applications, for example, the placement of a variable size character pattern into a display storage (bit addressable buffer).

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Generalized Pattern Transfer from Storage to Storage Bit Buffer

A method is described herein for transferring pattern data from a host array to a display bit buffer with windowing. The method includes a provision for rapid transfer of an arbitrary bit pattern from part of one storage array to another storage as required in various applications, for example, the placement of a variable size character pattern into a display storage (bit addressable buffer).

Storage is generally addressable in bytes or words. This article provides for the transfer of a pattern from any arbitrary bit location within any word to any arbitrary bit location in a word in another storage unit. In addition, by iterating this "horizontal transfer" process with an appropriate bit increment to access the vertical components of a pattern, one may move a two-dimensional bit source area to a corresponding area in the target storage.

Fig. 1 shows the source storage with an array located at an address designated SLOC. The dimensions of the array are designated as SDx, SDy. We will designate the 'upper left corner' of the source bit area as Sx, Sy, where these are the relative values of the bit distance from the origin of the source storage array. The dimensions of the area are represented as vector and will be designated as SLx, SLy. The area can be viewed as a window that determines a pattern in an area to be transferred.

Fig. 2 shows the addressing of the bit buffer. The coordinate pair TWx, TWy defines the origin of a window in the bit buffer. TDx, TDy specifies the size of the window. This window is used to accommodate data to be placed in many viewports. Many systems require raster data to be displayed from multiple environments. The target of the source bit pattern is an area which is addressed in a way similar to the source pattern. Tx,Ty locates the origin of the area, and TLx,TLy gives its size.

Fig. 3 shows the system for transmitting an image from source storage (through register M) to the bit buffer via register F. The storage and bit buffer each have a DMA (Direct Memory Access) controlled by the Controllers. DMA B has two ports for removing and replacing words.

The storage contains an array addressed by SLOC. The area (addressed by Sx, Sy in bits) is to replace the area (addressed by TX, Ty in bits) in the window (addressed by TDx, TDy in bits). The necessary parameters are sent to the controller with appropriate commands for data transfer.

The method of operation is for words to be removed from storage, with end bits set to zero by ANDing with register MSKX which is set by the controller. The bytes are transferred to register M and are shifted by the controller. Meanwhile, bytes from the bit buffer are placed in register B. Register MSKY (whose contents are supplied by the controller) is used to zero portions of the output of register B.

Finally, register M is ORed with Register MSKY and register B. Thus, a word from the targ...