HP 13255-91171 Universal Memory Module Dec78 free download

File name 13255-91171_Universal_Memory_Module_Dec78.pdf

HP 13255 UNIVERSAL MEMORY MODULE Manual Part No. 13255-v1171 REVISED DEC-26-78 DATA TERMINAL TECHNICAL INFORMATION HEWLETT~PACKARD Printed in U.S.A. 13255 1325,-91171/02 Univ~rsal Memory Module REV DtC-26-78 1.0 INTRODUCTION. 1.0.1 The Universal Memory ModuLe is used in the 264XX Terminals for Display Memory or Program ~emory. This read-write memory is normally only accessible through the terminAL bus (ROT). If it is connected to the Processor Module top plane it is then only accessible through the top plane bus (TOP). 1.0.2 The universal Memory MOdule consists of t~o completely independant m~mory modules which each use 8 16-Pin so~eted ~OS RAMS. The mOdules may be configured with 16K R~MS or~anized as 16,384 X 1 bit or 4K RAMS organized as 4,096 X 1 bit giving the following Universal Memory Module standard sizes. 8K 0 2 4K modul~s 16k 0 1 16k module, 1 vacant module 32k 0 2 16k modules 1.0.3 The memory mapping of the Universal Memo~y Module is unrestricted with the following exceptions: o In BOT or TOP mode the memory in the memory mapped 1/0 space I/O space (32K-36K) can only be used with an enhanced version of the Processor Module. o In BOT mode the module can overlay the 0-64K space occupied by TOP Read only memory (ROM) or Random access memory (RAM) in which case the BOT access is obtained by firmware inhibiting the TOP me~ory -this can only be done if the TOP memory is ~ddressable as all RAM or all ROM. o In TOP mode the module can occupy the same 0-64K space as TOP ROM, if none is present a second Universal ~emory Module addressed as ~OM (but functioning as RAM) may also be used. o In TOP mode Bank Switching is possible using an enhanced v~rsion of the Pracessor Module and the 16K or 32K confiqurations of Universal Memory module. This permits up to 4 memory modules to the overlay the 0-64K TOP memory space. Bank Switching can only be used with an enhanced version of the Processor Module. HP 13255 UNIVERSAL MEMORY MODULE Manual Part No. 13255-91171 REVISED OEC-26-78 ----------.----------------------~---~----~--~~-----------~------- ~OTICE The information cont