US4429306A
Expired / Lapsed
US
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Addressing system for a multiple language character generator
Assignee: International Business Machines Corp
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Filing: 1981-09-11
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Granted: 1984-01-31
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Expires: 2001-09-11
Abstract
Abstract A method and apparatus are disclosed for addressing a character generator memory containing symbols common to two or more languages in a common area of the character generator memory. Symbols which are special to the particular language being displayed are stored in one of a plurality of special symbol areas of the character generator memory. One of the special symbol areas contiguous with the common area is identified as a default symbol area. The proper special symbol area of the character generator memory is selected by comparing the high order bits of a display character code with compare bits to determine whether a different special symbol area of the character generator memory is to be substituted for the default area contiguous with the common area. If the compare bits indicate that a different special area of the character generator is to be substituted, the high order bits of the display character code are not directly used to address the character generator memory but are replaced by substitution bits to access that special symbol area unique to the language being displayed.
Inventors
- 👤 George C. Macauley
- 👤 William F. Nemecek
- 👤 Robert W. Roefer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:59
CPC Classifications
G; G09; G09G; G09G5/00; G09G5/22; G09G5/24; G09G1/00; G09G1/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
127 words
A method of retrieving picture elements from a character generating memory for display of a symbol comprising the steps of: providing a first plurality of bits of a display character code as part of an address to an address input of said memory; providing at least one compare bit: comparing another bit of said display character code with said compare bit and; substituting a plurality of bits for said another bit of said display character code as another part of said address to said address input of said memory, responsive to the result of said comparison in order to select a symbol which is special to a particular language; whereby a selected portion of said memory may be accessed alternatively to another selected portion of said memory.
Claim 2
Independent Claim
127 words
A method of retrieving picture elements from a character generating memory for display of a symbol comprising the steps of: providing a first plurality of bits of a display character code as part of an address to an address input of said memory; providing at least one compare bit: comparing another bit of said display character code with said compare bit and; substituting a plurality of bits for said another bit of said display character code as another part of said address to said address input of said memory, responsive to the result of said comparison in order to select a symbol which is special to a particular language; whereby a selected portion of said memory may be accessed alternatively to another selected portion of said memory.
Claim 3
Dependent Claim
93 words
In a character generator including a memory for storing the picture elements of a set of characters and a source of character codes, the improvement comprising: first storage means for storing n compare bits; second storage means for storing at least n+1 substitution bits; compare means for comparing the n high order bits of one of said character codes with said n compare bits; logic means responsive to the output of said compare means for gating at least n+1 substitution bits from said second storage means to the address input of said memory.
Claim 4
Dependent Claim
93 words
In a character generator including a memory for storing the picture elements of a set of characters and a source of character codes, the improvement comprising: first storage means for storing n compare bits; second storage means for storing at least n+1 substitution bits; compare means for comparing the n high order bits of one of said character codes with said n compare bits; logic means responsive to the output of said compare means for gating at least n+1 substitution bits from said second storage means to the address input of said memory.
Claim 5
Dependent Claim
65 words
A character generator comprising: a memory having a common symbol area, a default special symbol area, and at least one selectable special symbol area; compare means for comparing n bits of a character code with n bits designating said special symbol areas; substitution means responsive to said compare means for providing at least n+1 address bits designating a specific one of said special symbol areas.
Claim 6
Dependent Claim
65 words
A character generator comprising: a memory having a common symbol area, a default special symbol area, and at least one selectable special symbol area; compare means for comparing n bits of a character code with n bits designating said special symbol areas; substitution means responsive to said compare means for providing at least n+1 address bits designating a specific one of said special symbol areas.
Claim 7
Dependent Claim
40 words
The method of claim 1 further comprising the steps of: storing, responsive to at least one bit of another display character code, a plurality of bits of said another display character code as said compare bit and said substitute bits.
Claim 8
Dependent Claim
28 words
The character generator of claim 2 wherein said register further comprises a compare field for storing said n bits and a substitution field for storing and substitution bits.
Claim 9
Dependent Claim
29 words
The character generator of claim 2 further comprising control logic for storing in said register, a plurality of bits of a display character code which is a display order.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-30 | 1987-08-01 | 1988-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-30 | 1991-08-01 | 1992-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-30 | 1995-08-01 | 1996-01-31 | $7700.00 | Window Closed / Lapsed |