{File name:  StartCedar1.mc
 Description: Cedar emulator initialization,

 Last Edited:
  Trow	28-Oct-87  2:44:31 Created.
}


Set[xtFC0, 1] {see description of bits in Xfer};


	GOTOABS[B1MP799],					c3, at[BxMP799];

{write 799 in maintenance panel}
MP799:
	TT ¬ uMaintPanel, {maint panel code}			c1, at[B1MP799];
	rhTT ¬ uIORgnHigh,					c2;
	Noop,							c3;

	TOS ¬ 1F,						c1;
	TOS ¬ TOS LRot8,					c2;
	TOS ¬ TOS or 3 {1F03 byteswapped = 799'd},		c3;

	MAR ¬ [rhTT, TT + 0],					c1;
	MDR ¬ TOS,						c2;
	TT ¬ TT + 1, {maint panel down-notify mask}		c3;

	MAR ¬ [rhTT, TT + 0],					c1;
	Noop,							c2;
	TOS ¬ MD,						c3;

{TOS contains notify mask: byte-mask in high byte, byte offset in low}
	T ¬ uMesaProc,						c1;
	rhT ¬ uIORgnHigh,					c2;
	TT ¬ LShift1 (T + downNotifyBits),
		LOOPHOLE[niblTiming],				c3;

	MAR ¬ [rhT, T + notifiersLockMask],			c1;
	STK ¬ TOS, T ¬ TOS and ~0FF, CANCELBR[$,0],		c2;
	TOS ¬ MD, L4 ¬ SoftwareLockRets.StartCedar,		c3;

	rhTT ¬ STK, XLDisp,					c1;
{the following branch is reversal of Mesa byte order to do byte-swapping for IOP}
	TT ¬ RShift1 (TT + rhTT), LOOPHOLE[niblTiming],
		BRANCH[LowByteMask,$,2],			c2;
	rhT ¬ lock.or, SetMPIntIOP, CALL[SoftwareLock],		c3;
LowByteMask:
	rhT ¬ lock.or, SetMPIntIOP,				c3;

	MAR ¬ [rhIORgn, rIORgn + iopRequestsLock],		c1;
	T ¬ T LRot8, CANCELBR[SoftwareLockSideDoor,0],		c2;

	MDR ¬ 0, CANCELBR[$,0],					c2, at[SoftwareLockRets.StartCedar,10,SoftwareLockRets];
	TOS ¬ rhMDS, ClrMPIntIOP,				c3;

LastChance:
	Noop,							c1;
	SetIE,							c2;
	rhT _ xtFC0,						c3;

	TT ¬ uSDAddr,						c1;
	T _ TT + 276'b {T _ 1376'b},				c2;
	Udest _ T, L _ 0, YDisp, GOTO[EFCHaveLink],		c3;