Abstract: Simultaneous use of multiple expanded memory cards and their associated Expanded Memory Manager (EMM) device drivers in a computer system is provided. First, an expanded memory card is added and its EMM device driver will check to verify if another EMM driver is currently installed. If so, the new EMM device driver will take control of the existing EMM device driver in a master-slave relationship. The new EMM device driver (master) controls the existing EMM device driver (slave) by use of the slave's interrupt vector. That is, the master controls the slave by having an interrupt vector for the slave readdressed to be input to the master. Thereby, providing the master with the which expanded memory interrupts the slave was required to service. The master also takes control of all the slave's handles and pages by appearing as a requesting program application to the slave.

Abstract: A system and method makes use of the line-in, line-out connectors for each right and left stereo channel of an audio card to provide a communications network. The distributed computers are connected in a master/slave configuration. All of the slave systems have the line-in ports, and the line-out ports, connected together. The master system line-out is connected to each slave system line-in port, and the slave system line-out ports are connected to the master line-in port, for each channel. A communications protocol is provided wherein the master system allows audio and data information to be simultaneously transferred between the master and slave systems. The master provides a clock signal and performs arbitration in order to facilitate the information transfer.

Abstract: Simultaneous use of multiple expanded memory cards and their associated Expanded Memory Manager (EMM) device drivers in a computer system is provided. First, an expanded memory card is added and its EMM device driver will check to verify if another EMM driver is currently installed. If so, the new EMM device driver will take control of the existing EMM device driver in a master-slave relationship. The new EMM device driver (master) controls the existing EMM device driver (slave) by use of the slave's interrupt vector. That is, the master controls the slave by having an interrupt vector for the slave readdressed to be input to the master. Thereby, providing the master with the expanded memory interrupts the slave was required to service. The master also takes control of all the slave's handles and pages by appearing as a requesting program application to the slave.

Abstract: An EMM device driver command installation line is provided which may be easily and quickly interpreted by a user, an installation or a setup program. The physical memory is correlated to the installation line by a map of the 16 K-byte DOS memory segments from 0 to the memory segment above 1024 K-bytes. Different characters are assigned to represent the different types of parameters which may be found in DOS memory (0 to 1024 K-bytes), e.g. read only memory (ROM), or video memory. Additionally, characters may represent the page (single 16 K-byte segment and frame (4 sequential pages) locations that are usable by the EMM device driver, and informative to a user. In addition to the type of characters used, the character positions also provide usable information to the user since a one to one correspondence exists between the character position and the physical locations in DOS memory.