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US4125891A Expired / Lapsed US ⏱️ 0.0 years remaining

Arrangement for protecting data stored in a digital computer

Assignee: Bull SAS
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Filing: 1976-09-03
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Granted: 1978-11-14
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Expires: 1996-09-03
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Abstract

Abstract A memory space for storing computer instructions includes first and second groups of addresses for first and second types of computer instructions. The first and second groups of addresses are numbers in first and second bases, respectively. The memory space is addressed with signals representing numbers only in the second base. All of the addresses of the first base are expressed by numbers that form only some of the numbers of the second base. In response to an indication of the first type of computer instruction being read out of or into the memory, the addresses of the first base are converted into addresses of the second base.

Inventors

  • 👤 Guy G. Sauger

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 06:09
CPC Classifications
G; G06; G06F; G06F12/00; G06F12/14; G06F12/1458; G06F12/1491

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 196 words
In combination with a computer, the computer including: a first group of addresses for one type of computer instruction, said first group of addresses being represented in the computer as first signals representing numbers in a first base, and a second group of addresses for a second type of computer instruction, said second group of addresses being represented in the computer as second signals representing numbers in a second base, the numerical value of the second base exceeding that of the first base so that all of the addresses of the first base are expressed by numbers that form only some of the numbers of the second base; a memory with a portion thereof for storing computer instructions at addresses represented by numbers in the second base; means responsive to the first signals for converting the first signals, representing addresses of the first base, into third signals representing addresses of the second base in response to an indication of the one type of computer instructions being read out of or into memory; and means selectively responsive to the second and third signals for addressing said memory portion with signals representing numbers only in the second base.
Claim 2
Dependent Claim 196 words
In combination with a computer, the computer including: a first group of addresses for one type of computer instruction, said first group of addresses being represented in the computer as first signals representing numbers in a first base, and a second group of addresses for a second type of computer instruction, said second group of addresses being represented in the computer as second signals representing numbers in a second base, the numerical value of the second base exceeding that of the first base so that all of the addresses of the first base are expressed by numbers that form only some of the numbers of the second base; a memory with a portion thereof for storing computer instructions at addresses represented by numbers in the second base; means responsive to the first signals for converting the first signals, representing addresses of the first base, into third signals representing addresses of the second base in response to an indication of the one type of computer instructions being read out of or into memory; and means selectively responsive to the second and third signals for addressing said memory portion with signals representing numbers only in the second base.
Claim 3
Dependent Claim 44 words
The combination of claim 1 wherein the first base is base ten and the second base is greater than ten, said converting means including means for converting the first signals of base ten to the third signals of the second base greater than 10.
Claim 4
Dependent Claim 65 words
The combination of claim 2 further including means responsive to the first signal for sensing a value higher than nine being used to represent any order of an address in the first base while the indication of the first type of computer instruction is being derived, and means for preventing addressing of the memory portion in response to said value higher than nine being sensed.
Claim 5
Dependent Claim 83 words
The combination of claim 1 further including means responsive to the first signal for sensing a value higher than one less than the numerical value of the first base being used to represent any order of an address in the first base while the indication of the first type of computer instruction is being derived, and means for preventing addressing of the memory portion in response to said sensing of a value higher than one less than the value of the first base.
Claim 6
Dependent Claim 36 words
The combination of claim 1 wherein the first and second bases are respectively 10 and 16, said converting means including means for converting the first signals of base 10 to the third signals of base 16.
Claim 7
Dependent Claim 61 words
The combination of claim 1 wherein each of the first and second signals includes first and second indications respectively indicative of the first and second signals representing addresses of the first and second groups of addresses, and means responsive to the first and second indications for selectively enabling the addressing means to be responsive to the third and second signals, respectively.
Claim 8
Dependent Claim 74 words
The combination of claim 6 further including means responsive to the first signal for sensing a value higher than one less than a numerical value of the base being used to represent any order of an address in the first base while the first indication is being derived, and means for disabling the addressing means in response to said sensing of a value higher than one less than the value of the first base.

References Cited (Backward Citations)

US3786427A Cited
US3902164A Cited
US3902163A Cited
US3916385A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-11-13 1982-05-15 1982-11-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-11-13 1986-05-15 1986-11-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-11-13 1990-05-15 1990-11-14 $7700.00 Window Closed / Lapsed

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