HP 13255-91249 8085A Processor Module Feb82 free download

File name 13255-91249_8085A_Processor_Module_Feb82.pdf

BP 13255 PROCESSOR (SOS5A-2) MODULE Manual Part 10. 13255-~ 292 PRllITED q I :J.4f? FEB-14-S2 DATA TERMINAL TECHNICAL INFORMATION HEWLETT ltJ PACKARD Printed in U.S.A. 13255 13255-91252/02 Memory Controller Rev JUH-23-81 1.0 IHTRODUCTIOII 1.0.1 The Memory Controller Module has been designed to be used in the 2647F terminal. It is used to provide all randoll access aemory space required for the terminal environment; this includes variable space as well as basic procram and work space. It is accessed by the processor through the terminal bus. 1.0.2 The Memory Controller consists of control and timing circuitry and up to tour banks ot eight 64K socketed MOS RAM chips each for a total possible capacity ot 256K bytes. 1.0.3 The memory mapping ot the Memory Controller is as follows: there are two optional Ilapping possibilities. Which is selected depends on the presence or absence of jumper Wl. It Wl is absent, the board i. strapped as a 128K byte board which answers to the addresses tor variable space and basic space. It W1 is present, then the Memory Controller is strapped to be used in a RAM based terminal environment, answering to the terminal code addresses as well as the above mentioned variable and basic spaces. These addresses are determined by the state ot the three Ilost significant address bits, ADDR16, ADDR17, and ADDR18 as described below. 2.0 OPERATING PARAMETERS