ASMB,L,R
* 
*     NAME:   CMP.. 
*     SOURCE: 92070-18321 
*     RELC:   92070-1X321 
*     PGMR:   DJN 
* 
* 
*  **************************************************************** 
*  * (C) COPYRIGHT HEWLETT-PACKARD COMPANY 1980.  ALL RIGHTS      * 
*  * RESERVED.  NO PART OF THIS PROGRAM MAY BE PHOTOCOPIED,       * 
*  * REPRODUCED OR TRANSLATED TO ANOTHER PROGRAM LANGUAGE WITHOUT * 
*  * THE PRIOR WRITTEN CONSENT OF THE HEWLETT-PACKARD COMPANY.    * 
*  **************************************************************** 
* 
* 
* 
* THESE ROUTINES ARE PROVIDED TO ACHIEVE IDENTICAL DRIVERS BETWEEN
* THE XL, AND L OPERATING SYSTEMS. IT CAN BE INCLUDED WHEN GENERATING 
* AN L SYSTEM TO MAKE XL DRIVERS WORK ON THE L, AND TO ALLOW USER WRITTEN 
* L DRIVERS TO CONFORM TO THE EXTENDED MAPPED IO PROTOCOL.
* 
* 
      NAM CMP..,0  92070-1X321  REV.2040  800714
* 
      ENT $READ,$WRIT,$SETM 
      ENT $SETR,$SELR,$ONER,$ONEW 
A     EQU 0 
B     EQU 1 
$WRIT NOP 
      ISZ $WRIT     INCREMENT ADDRESS 
      STA B,I       PUT THE DATUM.
      JMP $WRIT,I 
* 
$ONEW NOP          SAME THING WITH L
      ISZ $ONEW    BUMP RETURN TWICE
      ISZ $ONEW 
      STA B,I      STORE DATA 
      JMP $ONEW,I  AND RETURN 
* 
$READ NOP 
      ISZ $READ     GET RETURN ADDRESS
      LDA B,I       GET THE DATUM 
      JMP $READ,I   RETURN
* 
$ONER NOP           NO DIFFERENCE WITH L
      ISZ $ONER 
      ISZ $ONER     BUMP RETURN TWICE 
      LDA B,I       GET DATA
      JMP $ONER,I 
* 
* THE ROUTINES $SETM AND $SETR ARE NOPS FOR THE L 
* 
$SETM NOP 
      JMP $SETM,I 
* 
$SETR NOP 
      CLA 
      CLB 
      JMP $SETR,I 
* 
* $SELR SELECTS THE RELOCATION REGISTER FOR A DMA TRANSFER. 
* ON THE XL, THE A REGISTER RETURN OF $SELR MUST BE STORED IN THE 
* LOWER 5 BITS OF THE DMA CONTROL WORD BEFORE INITIATING A DMA TRANSFER 
* INSIDE OF AN INTERFACE DRIVER. ON THE L, THESE BITS ARE DON'T CARES,
* BUT FOR SAKE OF CLEAN CODING, THIS L COMPATABILITY MODULE MERELY
* CLEARS THE A REGISTER.
* 
$SELR NOP 
      CLA 
      JMP $SELR,I 
      END 
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