A memory device operable at high-speed and with low power consumption is disclosed. The device in which row address information and column address information are incorporated in synchronism with a row strobe signal and a column strobe signal, respectively, and refresh is effected in response to a row address, comprises a plurality of groups of selection gates for selectively supplying the incorporated column address information to a part of a plurality of column address decoders.

A means and method for accessing a digital memory system in a manner permitting the transfer of a two-byte information signal into and out of a storage area defined by any two logically adjacent memory bytes. Provision is also made for maintaining a preselected locational integrity between the bytes forming the information signal.

A multiported random access memory (RAM) system comprising a RAM having a data port and an address and control port, plural data buffers each having a bidirectional input port and a bidirectional output port, a data bus connecting the output ports of the data buffers and the data port of the RAM, a multiplexer having plural address and control inputs and an address and control output, the address and control output being connected to the address and control port of the RAM, each of the address and control inputs for receiving address and control data associated with data stored in a specific buffer, a timing apparatus connected to each of the buffers and to a control input of the multiplexer for separately enabling the multiplexer to pass address and control data therethrough to the address and control port of the RAM or to receive data from the data port of the RAM, whereby the bidirectional data input ports of the buffers and each of the corresponding address and control input ports forms a separate time shared port to the RAM.

A loader which itself may be implemented in firmware, being permanently resident within a read-only microinstruction memory in a microprogrammable digital processor, or which may be implemented by a hardwired digital logic equivalent, is provided for binding the firmware structure of such microinstruction processor at user-program, load-time. This loader is preferably activated by the loading operation to read the loaded program's operating requirements and to equate these to system requirements and to firmware controller requirements. The loader may then call upon a library of firmware which may be optionally incorporated into the system, to select the specific firmware modules which are needed to execute that particular program, and to bind the selected firmware into the processor's microprogram read-write memory.

A control store coupled with a central processing unit to transfer information over a common electrical bus and coupled to transfer information over a private interface between the control store and unit. The control store includes firmware words for providing additional control of the unit, which also has a control memory for controlling the operation of the unit. The private interface is used to transfer addressed firmware words from the control store to the unit for use by the unit including generating the next address to be used by the control store, which next address is also provided from the unit to the control store over the private interface. Such private interface is also used to transfer the results of one or more tests performed by the unit, which results indicate which of at least two alternative addresses are to be used by the control store.