-- File: AltoRam.mesa,  Last Edit: HGM  July 18, 1980  8:31 AM

DIRECTORY
  PrincOps USING [zLIW, zJRAM, zPOP];

AltoRam: DEFINITIONS =
  BEGIN

  Shorten: PROCEDURE [LONG POINTER] RETURNS [POINTER] = MACHINE CODE
    BEGIN PrincOps.zPOP; END;

  -- This is a kludgy place to put this, but all the Alto drivers already use this module

  GetTicks: PROCEDURE RETURNS [CARDINAL] = INLINE
    BEGIN clock: POINTER TO CARDINAL = LOOPHOLE[430B]; RETURN[clock^] END;

  msPerTick: CARDINAL = 39;


  LoadRamAndBoot: PROCEDURE [filename: STRING];
  CantFindFile: ERROR;
  FileLooksCrufty: ERROR;

  -- Internal things used to prevent the microcode from getting confused
  --  when the bank registers are reset
  LockThingsInLowMemory: PROCEDURE;
  DoSilentBoot: PROCEDURE [WORD];
  UnBoot: PROCEDURE;

  -- Interface to Taft's microcode

  -- Beware: these routines assume that the stack does not have anything extra on it when they are called.  Also, PupChecksum is 
interruptable.  It assumes that the JRAM is alpha aligned which is forced by the preceeding LIW.


  ramOffset: CARDINAL = 1400B;

  silentBootAddr: CARDINAL = ramOffset + 0;
  SilentBoot: PROCEDURE [bootLocusVector: WORD] = MACHINE CODE
    BEGIN
    PrincOps.zLIW, silentBootAddr/256, silentBootAddr MOD 256;
    PrincOps.zJRAM;
    END;

  enableEiaAddr: CARDINAL = ramOffset + 1;
  EnableEia: PROCEDURE [p: POINTER] = MACHINE CODE
    BEGIN
    PrincOps.zLIW, enableEiaAddr/256, enableEiaAddr MOD 256;
    PrincOps.zJRAM;
    END;

  setLineTabAddr: CARDINAL = ramOffset + 1;
  SetLineTab: PROCEDURE [p: POINTER] = MACHINE CODE
    BEGIN
    PrincOps.zLIW, setLineTabAddr/256, setLineTabAddr MOD 256;
    PrincOps.zJRAM;
    END;

  pupChecksumAddr: CARDINAL = ramOffset + 2;
  PupChecksum: PROCEDURE [initial: WORD, where: POINTER, length: CARDINAL]
    RETURNS [WORD] = MACHINE CODE
    BEGIN
    PrincOps.zLIW, pupChecksumAddr/256, pupChecksumAddr MOD 256;
    PrincOps.zJRAM;
    END;

  changeControlRegAddr: CARDINAL = ramOffset + 3;
  ChangeControlReg: PROCEDURE [lineTimes4: CARDINAL, changeMask: WORD] = MACHINE
    CODE
    BEGIN
    PrincOps.zLIW, changeControlRegAddr/256, changeControlRegAddr MOD 256;
    PrincOps.zJRAM;
    END;


  END.