ISA EXPANSION CARD AND METHOD OF PROTECTING IBM-PC AND IMB-PC- COMPATIBLE COMPUTERS AGAINST UNAUTHORIZED ACCESS

The invention relates to an ISA-type expansion card and to a method of protecting the IBM-PC and IBM-PC-compatible computers against unauthorized use. The invention relates to an ISA-type card comprising an EEPROM-type memory block (1), a decoder block (2), a memory page switch block (3), a control assembly (4) and a standard ISA connector (5), and provided with a program checking the user's identity based on a password entered by means of the computer keyboard, by means of a flexible disk or by a combination thereof, and managing the list of users having authorized access to the computer, and with electronic circuits ensuring both the program and the users' data privacy. The protection method prevents the access to the program code and to the users' data, irrespective of the employed software hacker process. The card occupies a minimum memory interval in the memory address space reserved to ISA cards and does not employ the I/O port address space. Inventia se refera la o cartela de extensie de tip ISA si o metoda ce asigura protectia calculatoarelor IBM-PC si compatibile impotriva utilizarii de catre persoane neautorizate. Inventia consta dintr-o cartela de tip ISA, alcatuita dintr-un bloc de memorie de tip EEPROM (1), un bloc decodor (2), un bloc comutator de pagini de memorie (3), un bloc de control (4) si un conector standard ISA (5) si este prevazuta cu un program de verificare a identitatii utilizatorului pe baza unei parole ce poate fi introdusa prin intermediul tastaturii calculatorului, printr-un disc flexibil sau prin combinarea ambelor modalitati si de gestiune a listei utilizatorilor cu drept de acces la calculator si circuite electronice care asigura secretul programului si al datelor asociate cu utilizatorii. Metoda de protectie asigura imposibilitatea accesului la codul programului si la datele asociate cu utilizatorii, oricare ar fi procedeul software de atac folosit. Cartela ocupa un interval de memorie minim in spatiul de adrese de memorie rezervat cartelelor ISA si nu face uz de spatiul de adrese de porturi I/O.