diode matrix การใช้

• Before integrated circuits, other firmware devices included a discrete semiconductor diode matrix.
• A diode matrix is used as the control store or microprogram in many early computers.
• Some modern microprocessors and application-specific integrated circuits ( ASICs ) use a diode matrix or transistor matrix control store.
• :A diode matrix ROM has multiple address lines, each of which is connected to a number of output lines using diodes.
• Each step of the clock selected one or more signal lines in a diode matrix that enabled gates and other circuits on the machine.
• Here is a historical example of one diode matrix ROM panel .-- talk ) 06 : 17, 28 January 2009 ( UTC)
• The " blank " PLA from the chip manufacturer came with a diode matrix or transistor matrix with a diode ( or transistor ) at every intersection.
• DEC later added an optional diode matrix read-only memory for the PDP-11 that stored a bootstrap program of up to 32 words ( 64 bytes ).
• Strictly, " read-only memory " refers to memory that is hard-wired, such as diode matrix and the later mask ROM ( MROM ) which cannot be changed after manufacture.
• I once hand-wired a 30 byte diode matrix containing a ROM paper tape loader subroutine . . . ROM chips were prohibitively expensive and that was the only way to boot my hand-built Intel 8008 home computer.
• The microsequencer of many early computers, perhaps starting with the Whirlwind ( computer ), simply activated each row of the diode matrix in sequence, and after the last row was activated, started over again with the first row.
• The control store is a diode matrix : a two-dimensional lattice, where one dimension accepts " control time pulses " from the CPU's internal clock, and the other connects to control signals on gates and other circuits.