:TITLE[EOMLoTask];

%
Edit by Fiala 17 March 1982: absort EOMInit code; have init fall dirctly into
  eomLoSleep.
Edit by Fiala 28 April 1981: Replaced pNWW by IP[NWW]C.
Edit by srd March 27, 1980  4:51 PM	Put in new list overflow notify
Edit by srd March 27, 1980  4:38 PM	Fixed OUTPUT and LOADPAGE gotchas
Edit by srd March 26, 1980  4:02 PM	Modified low task size specification.
Edit by srd March 24, 1980  9:12 AM	Eliminated font banks.
Edit by srd February 26, 1980  2:34 PM	Added hooks for verdi disk change, put
		in font bank bypass code, and diagnostic register dump.
Edit by rej August 6, 1979  1:45 PM


The low task constructs parameter blocks, handles Mesa requests, and processes
various error conditions.
%

SetTask[eomLoTask];

eomLoTaskInit:
	eomCsbBaseLo _ (eomLhLoCsbBase), At[eomLoTaskInitLoc];
	eomCsbBaseLo _ (eomCsbBaseLo) or (eomRhLoCsbBase);
	eomCsbBaseHi _ (eomLhHiCSBbase);
	LoadPage[eomLoTaskPage] ;
	eomCsbBaseHi _ (eomCsbBaseHi) or (eomRhHiCSBbase), GoToP[.+1];

OnPage[eomLoTaskPage];

eomLoSleep:
	Call[eomLoTaskSwitch];

eomLoRun:
	T _ eomBandListPointer;
		*Set up the offset for fetching the new list entry.  The pointer is not
		*incremented here, because we may go to special reason processing, or
		*the new list may be full, and we may have to fetch this list entry again
		*This must be the second instruction for the IOATTEN to work properly.
	DBLGOTO[eomSpecialReason,eomBuildBlock,IOATTEN];

%	********************
	This is the normal low task activity.  The code comes here if there is no IOATTEN
	present at eomLoRun+1.
%	********************

eomBuildBlock:
		*T already loaded above
	PFETCH2[eomBandListA,eomBListEntryA];
		*force the interlock to work and dispatch on the three most
		*significant bits of the entry type code
		*This will process the most common type of band list entries on the first
		*dispatch.
	DISPATCH[eomBListEntryA,0,3], LU _ eomBListEntryA;
		*Now we can increment the offset pointer because the new list is known to
		*contain space for the parameter block.  T will be used as a memory offset
		*if the entry is a rule.
	DISP[eomEntryType], eomBandListPointer _ T _ (eomBandListPointer) + (2C);

%	********************
	BLOCK BUILDER TRANSFER BRANCH 0
	This branch processes type 1 band list entries with font IN [0..7]
%	********************

eomEntryType:
		*high 2 font bits are zero, pick up the low 3 bits in T and get the parm
		*block fragment.
	T _ LDF[eomBListEntryB,0,3], GOTO[eomGenFontParmBlock], AT[loTaskBlockBldDispatch];


%	********************
	BLOCK BUILDER TRANSFER BRANCH 1
	This branch processes type 1 band list entries with font IN [10B..17B]
%	********************

		*the high 2 font bits are known to be 01, pick up the low 3 bits
	T _ (10C), GOTO[eomConstructFontCode], AT[loTaskBlockBldDispatch,1];

%	********************
	BLOCK BUILDER TRANSFER BRANCH 2
	This branch processes type 1 band list entries with font IN [20B..27B]
%	********************

		*the high 2 font bits are known to be 10, pick up the low 3 bits
	T _ (20C), GOTO[eomConstructFontCode], AT[loTaskBlockBldDispatch,2];

%	********************
	BLOCK BUILDER TRANSFER BRANCH 3
	This branch processes type 1 band list entries with font IN [30B..37B]
%	********************

		*the high 2 font bits are known to be 11, pick up the low 3 bits
	T _ (30C), AT[loTaskBlockBldDispatch,3];
eomConstructFontCode:
	T _ (LDF[eomBListEntryB,0,3]) OR T, GOTO[eomGenFontParmBlock];

%	********************
	BLOCK BUILDER TRANSFER BRANCH 4
	This branch processes type 2 band list entries (Rules).
%	********************

eomBuildRule:
		*this is a 4 word band list entry, fetch the other 2 words and stash in
		*eomFragA and eomFragB which will not be used otherwise.  Note that eomFragC and
		*eomFragD do not contain any information, and may be used as temps.  T was
		*already loaded with eomBandListPointer at the top level dispatch.
	PFETCH2[eomBandListA,eomFragA], AT[loTaskBlockBldDispatch,4];
		*Pick up the rule load block number.
		*(most significant 6 bits of the rule load number)
	T _ LDF[eomBListEntryB,0,6], TASK;
		*Bump the band list pointer to account for words 3 and 4 of the rule entry.
	eomBandListPointer _ (eomBandListPointer) + (2C);
		*Fetch a double word from the junk area.  This has been initialized by the
		*application software to contain a skeleton of a rule parameter block.
		*The words at 10 and 11 contain word 0 and a font bank relative pointer
		*to the beginning of the rule loads.
	PFETCH2[eomParameterTransferBaseA,eomFragC,10];
		*Stash the rule load block number in eomTemp for shifting.
	eomTemp _ T;
		*Construct partial parameter word 2 to indicate
		*blocks to request = 0, rule = true, save partial state,
		*previous line not present, line buffer position = 0.	
	eomParmC _ (ruleParmWord2);
		*Pick up the word pointer from the low 4
		*bits of the rule load number field in the second band list entry word and
		*shift to the proper field.
	T _ (170000C);
	T _ (LSH[eomBListEntryB,6]) AND T;
		*Stash away the completed word 2 of the parameter block.
	eomParmC _ (eomParmC) OR T;
		*Fetch the short base pointer which was obtained from the junk area.
	T _ eomFragD;
		*Multiply the rule number by 16 and add to the base.  The subroutine merges
		*the current default zPlane information into this and stores the result in
		*eomParmB (rule parameter word 1).
	T _ (LSH[eomTemp,4]) + T, CALL[eomSnarfZPlaneInfo];
	T _ (eomFragC), USECTASK, CALL[eomStashTInParmA];
		*Construct the mask for use in building the height.  This mask has zero
		*bits (which will be complemented to one bits) in the positions where
		*the raw data flag and the fresh start bit must go.
	T _ (34000C);
		*construct parameter word 3 to indicate fresh start, raw data, nibble
		*pointer = 0, font, and height from band list entry.  Also compute
		*adjustment to height, and compute rule mask.
		*Dispatch on the 2 least significant bits of the height.
	DISPATCH[eomFragB,16,2];
		*eomFragC now has ones in bits 5-15 and a 1 in bit position 1.
	eomFragC _ (ZERO) OR NOT T, DISP[eomSetUpRuleMask0];

	*eomFragD is no longer significant, so it is used here as a temp
eomSetUpRuleMask0:	*set up T to indicate no adjustment to height
	T _ (1C), AT[ruleMaskDispatch];
		*set up eomFragD to provide 000 for the rule mask and indicate rule
	eomFragD _ (200C), GOTO[eomMergeHeight];
eomSetUpRuleMask1:
		*set up eomFragD to provide 111 for the rule mask and indicate rule
	eomFragD _ (360C), GOTO[eomMergeHeightSetT], AT[ruleMaskDispatch,1];
eomSetUpRuleMask2:
		*set up eomFragD to provide 011 for the rule mask and indicate rule
	eomFragD _ (260C), GOTO[eomMergeHeightSetT], AT[ruleMaskDispatch,2];
eomSetUpRuleMask3:
		*set up eomFragD to provide 001 for the rule mask and indicate rule
	eomFragD _ (220C), GOTO[eomMergeHeightSetT], AT[ruleMaskDispatch,3];
eomMergeHeightSetT:
		*Set T to indicate a +1 adjustment to the height.
	T _ (0C);
eomMergeHeight:
		*pick up the 11 most significant bits of the height from the band list entry
		*and subtract the increment value.  This increment value will be either 0 or 1.
		*The value supplied to the hardware must be one less than the value in the
		*band list entry.  Therefore, if the increment value is one, subtract 0 and if
		*it is zero, subtract 1.
	T _ (LDF[eomFragB,3,13]) - T, CALL[eomLoTaskSwitch];
		*Take the ones complement of the height, and mask off the most significant
		*bits to restrict the value to only the height field.  The FRD bit is
		*automatically generated at this point, since the most significant bits of
		*NOT T will be ones.
	T _ (eomFragC) AND NOT T;
		*Stash away parameter word 3 and output the quad word to the new list.
	eomParmD _ T, CALL[eomRuleStashSub];
		*Parameter block word 4 need not be initialized in this case because of the
		*rule being forced raw data.
		*Pick up the width from the band list entry.  The subroutine stashes it in
		*eomParmB.
	T _ eomFragA, USECTASK, CALL[eomStashTInParmB];
		*set up the X and Y values
	T _ LDF[eomBListEntryB,12,6];	*stash the X value
	eomParmC _ T;
	T _ LDF[eomBListEntryA,3,15];
		*stash the Y value and output the quadWord to the new list
	eomParmD _ T, CALL[eomRuleStashSub];
		*construct word 8 of the parameter block
		*eomFragD already contains the low byte of word 8, except for the ink setting,
		*from the rule setup dispatch above.
	T _ (eomFragD) OR (partialStateSave);	*indicate partial state save
		*The sign bit of the eomInkSetting, which is used as a fast branch
		*flag to indicate abnormal ink must be masked out.
		*Goto eomAbnormalInkA to stash parameter word 8 and output the quadWord
		*to the new list.
	T _ (RHMASK[eomInkSetting]) OR T, GOTO[eomAbnormalInkA];

%	********************
	BLOCK BUILDER TRANSFER BRANCH 5
	This branch processes type 3 band list entries (Command Codes).
%	********************

		*dispatch on the 4 bits of command
	DISPATCH[eomBListEntryA,6,4], AT[loTaskBlockBldDispatch,5];
	DISP[eomType6NOP];

eomType6NOP:
		*this is the nop command
	GOTO[eomLoSleep], AT[type6Dispatch];

eomType6EOP:
		*This is the end of page command.  This is faked by setting the flag to indicate
		*end of band processed, and backing up the band list pointer to point once again
		*to the end of page entry.
		*Set up for the branch on EOP already sent.
	LU _ (eomState) AND (eopAlreadySent), AT[type6Dispatch,1];
		*Do the branch, and set up eomFragB in case the branch is taken.
	GOTO[eomFirstEOPencounter,ALU=0], eomState _ (eomState) OR (eopAlreadySent);
		*Go and pause the low task.  Also back up the band list pointer.
	eomBandListPointer _ (eomBandListPointer) - (2C), GOTO[eomType6EOB];
eomFirstEOPencounter:
		*Back up the band list pointer.
	eomBandListPointer _ (eomBandListPointer) - (2C);
		*Task out due to length of modify wakeup reasons subroutine.
	CALL[eomLoTaskSwitch];
		*Store the modified wakeup reasons.
	T _ (EOPProcessed), CALL[eomModifyWakeupReasons];
		*Go to pause the low task.
	GOTO[eomNoNewListOverflow];

eomType6EOB:
		*Check for new list overflow.  First, pick up the maximum allowable new
		*list pointer value (the start of old list).
	T _ (eomState) AND (newListSizeMask), AT[type6Dispatch,2];
	CALL[eomLoTaskSwitch];
		*Subtract this from the current end of new list.
	LU _ (eomNewListWrite) - T;
	DBLGOTO[eomNewListOverflow,eomNoNewListOverflow,ALU>=0];
eomNewListOverflow:
		*The new list has overflowed, send the error notify.
	T _ (newListOverflow);
	CALL[eomModifyWakeupReasons];
	NOP;
eomNoNewListOverflow:
		*This is the end of band command.  This simply sets the band done flag,
		*and pauses the low task.
	eomState _ (eomState) OR (bandDone);
		*Output the command for the low task automaton to pause.  Also, activate the
		*high task if it needs it.  It could be paused waiting for the band done
		*indication before sending out the end of band character.
	INPUT[eomTemp,resetLoTaskRun];
	LU _ eomTemp, CALL[eomActivateHiTaskFromLoTask];
	GOTO[eomLoSleep];

eomType6ZPlane:
		*this is the z-Plane change command.
		*pick up the z-Plane.
	T _ LDF[eomBListEntryA,14,4], AT[type6Dispatch,3];
	eomZPlane _ T;
		*Pick up the ink setting, shift and mask to place it in the field where
		*it is used.
	T _ (14C);
	T _ (RSH[eomBlistEntryA,10]) AND T;
		*Stash the ink setting, and check for abnormal ink.
		*Abnormal ink is anything except visible black.
	DBLGOTO[eomNormalInk,eomAbnormalInk,ALU=0], eomInkSetting _ T;
eomNormalInk:
		*Normal ink; don't do anything funny.
	GOTO[eomLoSleep];
eomAbnormalInk:
		*abnormal ink.  Set the sign bit to be used as a fast branch flag
		*to indicate the abnormality
	eomInkSetting _ (eomInkSetting) OR (abnormalInkIndication), GOTO[eomLoSleep];

eomType6Link:
		*This is the link format
	T _ eomBListEntryB, AT[type6Dispatch,4];
	eomBandListPointer _ T, GOTO[eomLoSleep];

eomType6Link&EOB:
		*this combines link format with end of band.  Perform the link
		*here, then branch to the EOB code.
	T _ eomBListEntryB, AT[type6Dispatch,5];
	eomBandListPointer _ T, GOTO[eomType6EOB];

eomType6Link&ZPlane:
		*this combines link format with z-plane change.  Perform the link here,
		*then branch to the z-Plane change code.
	T _ eomBListEntryB, AT[type6Dispatch,6];
	eomBandListPointer _ T, GOTO[eomType6ZPlane];

eomType6FBank:
		*this is a font bank change
	GOTO[eomLoSleep], AT[type6Dispatch,7];

eomType6FBank&EOB:
		*this combines a font bank change with an end of band.  The font bank
		*is done here, then the EOB code is branched to
	GOTO[eomType6EOB], AT[type6Dispatch,10];

eomType6FBank&ZPlane:
		*this combines a font bank change with a z-Plane change.  The font bank
		*change is done here, followed by a branch to the z-Plane code.
	GOTO[eomType6ZPlane], AT[type6Dispatch,11];

%	********************
	BLOCK BUILDER TRANSFER BRANCH 7
	This branch processes type 4 band list entries (Images).
%	********************

eomBuildType2:
	T _ eomBListEntryB, CALL[eomBuildType4Sub], AT[loTaskBlockBldDispatch,7];
	T _ (eomBListEntryB) + (4C), CALL[eomBuildType4Sub];
	T _ (eomBListEntryB) + (10C), CALL[eomBuildType4Sub];
		*increment the write pointer to take account of the last quadword, which
		*is not transferred.  Go and remove the hi task pause, if one is in effect.
	eomNewListWrite _ (eomNewListWrite) + (4C), GOTO[eomActivateHiTask];

%	********************
	This is the exceptional low task activity.  The code comes here if there is an IOATTEN
	present at eomLoRun+1.
%	********************

eomSpecialReason:
		*Get the wakeup reason from the hardware.  NOTE-- this value in eomFragc
		*is also used in the eomMesaCommand dispatch if the special reason is a
		*mesa command.
	INPUT[eomFragC,loTaskStatus];
	CALL[eomLoTaskSwitch];
		*dispatch on the reason
	DISPATCH[eomFragC,16,2], LU _ eomFragC;	*force the interlock to work;
		*Load up a 1 for use if the branch is band switch.
	eomFragB _ (1C), DISP[eomNoStatus];

%	********************
	SPECIAL TRANSFER BRANCH 0
	This branch is an error.  Status zero should never occur with the IOATTEN line
	raised.
%	********************

eomNoStatus:
	GOTO[eomLoSleep], AT[loTaskMainDispatch];



%	********************
	SPECIAL TRANSFER BRANCH 1
	This code is run if a parity error was detected.
%	********************

eomParityError:
		*Merge the parity error wakeup reason in with whatever else is already
		*there.
	T _ (parityError), AT[loTaskMainDispatch,1];
	CALL[eomLoTaskSwitch];
		*This subroutine is so long, must task right before calling it.
	CALL[eomModifyWakeupReasons];
	INPUT[eomTemp,resetParityError];
eomLoTaskResetInterlock:
	LU _ eomTemp, GOTO[eomLoSleep];



%	********************
	SPECIAL TRANSFER BRANCH 2
	The code comes here to handle a mesa request.
%	********************

eomMesaCommand:
		*Pick up the mesa command field and dispatch on it.
	DISPATCH[eomFragC,11,3], AT[loTaskMainDispatch,2];
	DISP[eomMesaCommandBase];

eomDummyDispatch5:
	GOTO[eomResetMesaRequestCode], AT[loTaskMesaDispatch,5];

%	********************
	MESA COMMAND TRANSFER BRANCH 0 - - SECOND LEVEL DISPATCH
	Parametric Page Generation Startup
	The code comes here to handle a type 0 Mesa request: set up internal registers
	from the CSB and start generating parameter blocks.  This is the normal parametric
	page printing start.
%	********************

eomMesaCommandBase:
		*Clear the bitMapFirst indication, and indicate parametric time
		*operation starting from the new list
	eomState  _ (newListAndParametricMode), AT[loTaskMesaDispatch];

eomMesaCommandBaseA:
		*This is the entry point from the real time page print option.
		*Fetch the long pointer to the working storage.  Also activate the low
		*task wakeup automaton.
	PFETCH2[eomCsbBaseLo,eomParameterTransferBaseA,workingStorageOffset],
		CALL[eomActivateLoTask];
		*Fetch the skeleton for the band buffer command word.
		*This skeleton will be in word 12B of the junk area.  Also, initialize the
		*new list ring.
	PFETCH1[eomParameterTransferBaseA,eomFragA,12], CALL[eomInitNewList];
		*Fetch the word to be sent to the OPC startup register, and the indication
		*of how large the new list should be.
	PFETCH2[eomCsbBaseLo,eomFragC,mesaCommandOffset], CALL[eomLoTaskSwitch];
		*eomFragD contains the new list size in the 5 low order bits.
	eomFragD _ LSH[eomFragD,12];
		*Be paranoid, mask the field in case Mesa is being bad.
	T _ (eomFragD) AND (newListSizeMask);
	eomState _ (eomState) OR T;
		*initialize the workspace.  The low 16 words of the workspace are reserved
		*for misc. junk.
	eomOldListRead _ T;
	eomOldListWrite _ T;
		*fetch the long pointer to the band list
	PFETCH2[eomCsbBaseLo,eomBandListA,bandListOffset];
		*initialize the offset from the band list base
	eomBandListPointer _ (0C);
		*Initialize the active attributes to image, to force a setup for any first
		*data block.  The sign bit set means that the initial data block handler in
		*the hi task will not attempt to save any parameters about image 3 away in
		*the junk area. (eomActiveAttributes = 7 implies image # 3)
	eomActiveAttributes _ (ZERO) - 1;
		*Fetch the short pointer to the parameter block fragments.  Note that this
		*pointer is relative to the working storage long pointer
	PFETCH1[eomCsbBaseLo,eomFragments,fragmentsOffset];
		*indicate no parameter blocks in either list
		*empty is indicated by the sign bit set, that is, -1.
	eomOldBlocksFull _ (ZERO) - 1;
	eomOldBlocksReturned _ (ZERO) - 1;
		*Output the band buffer command fetched from word 12B in the junk area.
	OUTPUT[eomFragA,bandBufferCmndReg];
		*Initialize to hi task not paused.
	eomState _ (eomState) OR (hiTaskRunning);
		*Perform the OUTPUT to start the EOM.
	OUTPUT[eomFragC,opcStartupOut];
eomResetMesaRequestCode:
		*reset the Mesa request
		*This is the location to branch to when the mesa request needs resetting.
	INPUT[eomTemp,resetMesaCommand], GOTO[eomLoTaskResetInterlock];

%	********************
	MESA COMMAND TRANSFER BRANCH 1 - - SECOND LEVEL DISPATCH
	Reset Wakeup Reason
%	********************

eomResetWakeupReason:
		*ALL CODE BETWEEN THE PFETCH4 AND THE PSTORE4 MUST BE DONE WITHOUT A TASK
		*SWITCH, OTHERWISE THE HIGH TASK COULD MODIFY THE WAKEUP REASON AFTER THE
		*PFETCH AND BEFORE THE PSTORE AND THAT MODIFICATION WOULD BE DESTROYED
		*WHEN LO TASK DID THE PSTORE4

		*Pick up the current wakeup reason word in eomParmB and the mesa command
		*in eomParmC.
	PFETCH4[eomCsbBaseLo,eomParmA,wakeupMaskOffset], AT[loTaskMesaDispatch,1];
		*Load T with the mask to use (from mesa command).
	T _ eomParmC;
		*The usectask call is manditory to allow time for eomFragB to be properly
		*stored prior to the start of the PSTORE.
	eomParmB _ (eomParmB) AND T, USECTASK, CALL[eomLoTaskSwitch];
		*Store the masked reasons word back in the CSB.
	PSTORE4[eomCsbBaseLo,eomParmA,wakeupMaskOffset], CALL[eomLoTaskSwitch];
	GOTO[eomResetMesaRequestCode];

%	********************
	MESA COMMAND TRANSFER BRANCH 2 - - SECOND LEVEL DISPATCH
	Continue Parametric Page Print
%	********************

eomContinueParaPrint:
		*Clear the bitMapFirst indication.  The parametric operation flag is still
		*set.  Also indicate no freezeEOBChar state.
	eomState _ (eomState) AND NOT (firstParametricAndBandDone), AT[loTaskMesaDispatch,2];
	eomState _ (eomState) AND NOT (freezeEOBChar);
		*Activate the low task.  This subroutine does not use T.
	T _ eomOldBlocksReturned, CALL[eomActivateLoTask];
		*Set the old blocks full value for the upcoming band to the number of blocks
		*returned in the previous band.  Also, initialize the new list parameters.
	eomOldBlocksFull _ T, CALL[eomInitNewList];
		*Initialize the active attributes to image, to force a setup for the first
		*data block of the next band.  Without this, the data transfer base can be
		*left pointing to the bitmap return buffer.  The sign bit set means that the
		*initial data block handler in the hi task will not attempt to save any
		*parameters about image 3 away in the junk area. (eomActiveAttributes = 7
		*implies image # 3)
	eomActiveAttributes _ (ZERO) - 1;
		*Set the old blocks returned value to its initial value to indicate no blocks
		*returned.  Also, activate the hi task.
	eomOldBlocksReturned _ (ZERO) - 1, CALL[eomActivateHiTaskFromLoTask];
		*Reset the mesa request wakeup for the lo task.
	GOTO[eomResetMesaRequestCode];

%	********************
	MESA COMMAND TRANSFER BRANCH 3 - - SECOND LEVEL DISPATCH
	Increment Image Sector Value
%	********************

eomIncrementImSectVal:
		*Pick up the image number to increment the sector count from.
		*eomFragA will contain the image number (0,1,2, or 3).
	PFETCH1[eomCsbBaseLo,eomFragA,mesaCommandOffset], AT[loTaskMesaDispatch,3];
		*Set up the offset for fetching the sector count
	T _ (20C);
	T _ (LSH[eomFragA,2]) + T, CALL[eomLoTaskSwitch];
		*
		*ALL THE CODE BETWEEN THE FOLLOWING "LU _" UP TO THE PSTORE4 MUST BE DONE
		*WITHOUT A TASK SWITCH, OR THE HIGH TASK CAN COME IN IN THE MIDDLE AND MODIFY
		*THE COUNT OF SECTORS AVAILABLE WITHOUT THE KNOWLEDGE OF LO TASK.
		*THIS IS TRUE WHETHER THE IMAGE IS ACTIVE OR NOT (it could become active
		*after the PFETCH4 but before the PSTORE4).
		*
	LU _ (LSH[eomActiveAttributes,2]) - T;
	DBLGOTO[eomImageActive,eomImageNotActive,ALU=0];
eomImageActive:
		*The image data is already present in the quad block starting at
		*eomDataTransferBaseA, so no fetch is required.
	eomRingChar _ (eomRingChar) + (incSectorsFilledByOne);
	eomSectorsFilled _ (eomSectorsFilled) + 1, TASK;
	PSTORE4[eomCsbBaseLo,eomDataTransferBaseA];
	GOTO[eomResetMesaRequestCode];
eomImageNotActive:
	PFETCH4[eomCsbBaseLo,eomParmA];
	eomParmD _ (eomParmD) + (400C);
		*The NOP is manditory to insure that eomParmD is stored prior to the
		*start of the PSTORE4.
	NOP, TASK;
	PSTORE4[eomCsbBaseLo,eomParmA];
		*Go and reset the Mesa request.
	GOTO[eomResetMesaRequestCode];

%	********************
	MESA COMMAND TRANSFER BRANCH 4 - - SECOND LEVEL DISPATCH
	Dump 64 CPU registers to main memory.
%	********************
eomDiagnosticRegDump:
		*Pick up the microcode long pointer from the mesa command and the word
		*following.
	PFETCH2[eomCsbBaseLo,eomFragA,mesaCommandOffset], AT[loTaskMesaDispatch,4];
		*Initialize eomFragC to be an offset.
	eomFragC _ (100C), CALL[eomLoTaskSwitch];
	NOP;

eomRegDumpLoopHead:
	T _ STKP;
		*Use eomFragD to save the stack pointer.
	eomFragD _ T;
		*Load the stack pointer for the current quad block.
	STKP _ eomFragC;
		*Set up the offset from the double word base.
	T _ (eomFragC) - (100C);
	PSTORE4[eomFragA,STACK];
		*Retreive the actual stack pointer.
	eomFragD _ (eomFragD) XOR (377C);
		*Restore the stack pointer.
	STKP _ eomFragD, CALL[eomLoTaskSwitch];
	eomFragC _ (eomFragC) + (4C);
		*Check for completion.
	LU _ (eomFragC) - (200C);
	DBLGOTO[eomRegDumpLoopHead,eomRegDumpDone,ALU<0];
eomRegDumpDone:
	GOTO[eomResetMesaRequestCode];

%	********************
	MESA COMMAND TRANSFER BRANCH 6 - - SECOND LEVEL DISPATCH
	Terminate Page Print
%	********************

eomTerminatePagePrint:
		*Zero the wakeup reasons word;
	eomFragB _ 0C, AT[loTaskMesaDispatch,6];
	CALL[eomLoTaskSwitch];
		*Output garbage to register 0 to do the IORESET.  The output must be done
		*twice for the hardware to completely reset.
	OUTPUT[eomFragA,0];
	OUTPUT[eomFragA,0];
		*The store is done here to allow eomFragB to be stored;
	PSTORE1[eomCsbBaseLo,eomFragB,wakeupReasonOffset], GOTO[eomResetMesaRequestCode];

%	********************
	MESA COMMAND TRANSFER BRANCH 7 - - SECOND LEVEL DISPATCH
	This option handles the startup of a real time page print.
%	********************

eomStartRealTimePage:
		*Intialize the eomHiTaskState value to indicate real time page print and
		*working from new list.  Then go and set up as in a parametric page print.
	eomState _ (workingFromNewList), GOTO[eomMesaCommandBaseA],
		AT[loTaskMesaDispatch,7];

%	********************
	SPECIAL TRANSFER BRANCH 3
	The code comes here to handle a band switch.
%	********************

eomBandSwitch:
		*Fetch the count of bands processed.  The count will be in eomParmD.
	PFETCH4[eomParameterTransferBaseA,eomParmA,thirdJunkQuad],
			AT[loTaskMainDispatch,3];
		*Set up to send the notification of band switch;
	T _ (bandSwitch), CALL[eomLoTaskSwitch];
		*Increment the bands processed count.
	eomParmD _ (eomParmD) + 1, CALL[eomModifyWakeupReasons];
		*Check to see if we are in parametric or real time mode.
	LU _ (eomState) AND (parametricModeFlag);
		*Check for parametric band switch.  If it is real time band switch, update
		*the old list full values.  Also, store the count of bands processed.
	GOTO[eomParametricBandSwitch,ALU#0],
		PSTORE4[eomParameterTransferBaseA,eomParmA,thirdJunkQuad];
		*Output the start bit, set up in the DISP instruction.  This is required
		*in real time operation.  Also, send the band switch notification.
	OUTPUT[eomFragB,opcStartupOut];
	T _ eomOldBlocksReturned;
	eomOldBlocksFull _ T;
	eomOldBlocksReturned _ (ZERO) - 1;

eomParametricBandSwitch:
		*Reset the wakeup condition.
	INPUT[eomTemp,resetBandSwitch], GOTO[eomLoTaskResetInterlock];



eomGenFontParmBlock:
		*T must contain the five bit font number when this code block is entered.
		*Stash this in eomFragA.
	eomFragA _ T, TASK;
		*Shift the font number up (multiply by 128) to make room for the character
		*code.
	eomFragA _ LSH[eomFragA,7];
		*Pick up the character code.
	T _ (LDF[eomBListEntryB,3,7]);
		*Merge in the character code with the font number * 128.
	eomFragA _ (eomFragA) OR T;
		*Multiply by 4 for indexing quadword fragments
	T _ LSH[eomFragA,2];
		*add in the base offset
	T _ (eomFragments) + T, TASK;
		*Fetch the fragment.
	PFETCH4[eomParameterTransferBaseA,eomFragA];
		*Move the first word of the parameter block out of the fragment.
	T _ (eomFragA);
	eomParmA _ T;
		*Construct the third parameter word and stash it.  This word is
		*all zero for a startup font character, except for the word pointer
		*and the previous line present bit.
		*Pick up the word pointer and shift it to the proper location.
	T _ LSH[eomFragB,14];
	eomParmC _ T;
		*OR in the bit to indicate previous line not present.
	eomParmC _ (eomParmC) OR (previousLineNotPresent);
		*get the second parameter word and stash it.  This involves masking out the
		*word pointer and replacing it with the current z-Plane setting
	T _ (eomFragB) AND NOT (17C), CALL[eomSnarfZPlaneInfo];
		*move the fourth word
	T _ eomFragC;
		*output the first parameter quad
	eomParmD _ T;
	eomNewListWrite _ T _ (eomNewListWrite) + (4C);
	PSTORE4[eomParameterTransferBaseA,eomParmA];
		*create the run length and terminator word and stash it.  The run length
		*must be initialized to maximum, all ones.  The terminator doesn't matter.
	eomParmA _ (ZERO) -1;
		*set up parameter word 5 from the fragment
	T _ eomFragD, USECTASK, CALL[eomStashTInParmB];
	GOTO[eomNormalInkB,R>=0], A _ eomInkSetting;
		*the ink is abnormal, so the force word 8 to zero bit must be cleared.
	eomParmB _ (eomParmB) AND NOT (forceWord8ToZero);
eomNormalInkB:
		*set up the Y value
	T _ LDF[eomBListEntryA,3,15];
	eomParmD _ T;
		*set up the X value
	T _ LDF[eomBListEntryB,12,6];
		*output the second parameter quad
	eomParmC _ T, CALL[eomRuleStashSub];
		*check the abnormal ink flag, and pick up the ink setting in case we need it.
	DBLGOTO[eomNormalInkA,eomAbnormalInkA,R>=0], T _ RHMASK[eomInkSetting];
eomAbnormalInkA:
		*Stash the ink setting, and output the third quad word.
	eomParmA _ T, CALL[eomRuleStashSuB];
		*bump the write pointer to pass over the fourth quad word.
	eomNewListWrite _ (eomNewListWrite) + (4C), GOTO[eomActivateHiTask];
eomNormalInkA:
		*bump the newPointer up to the start position for the next parameter block
	eomNewListWrite _ (eomNewListWrite) + (10C), GOTO[eomActivateHiTask];

eomActivateHiTask:
		*Indicate the addition of another block to the new list.
		*Also, activate the hi task if it needs it.
	eomNewBlocksFull _ (eomNewBlocksFull) + 1, CALL[eomActivateHiTaskFromLoTask];
	GOTO[eomLoRun];


********************

*LOW TASK SUBROUTINES

********************

eomSnarfZPlaneInfo:
		*pick up the default z-Plane information
	T _ (RHMASK[eomZPlane]) OR T;
eomStashTInParmB:
		*Stash the second parameter
	eomParmB _ T, RETURN;

eomStashTInParmA:
	eomParmA _ T, RETURN;

% SUBROUTINE eomRuleStashSub AND eomBuildType4Sub ********************
	This subroutine stashes parameter blocks into the new list and bumps the new list
		write pointer.
% ********************

eomBuildType4Sub:
		*Fetch the quadblock from the parameter block
	PFETCH4[eomBandListA,eomParmA];
	LU _ eomParmD;	*force the interlock
eomRuleStashSub:
	eomNewListWrite _ T _ (eomNewListWrite) + (4C);
	PSTORE4[eomParameterTransferBaseA,eomParmA], RETURN;


% SUBROUTINE eomActivateLoTask ********************
	This subroutine sends the command to the hardware to activate the low task wakeup
		automaton.
% ********************

eomActivateLoTask:
	eomFragA _ setLoTaskRun;
	OUTPUT[eomFragA,loTaskCommandReg];
eomInterlockOUTPUT:
		*Interlock to force completion of the OUTPUT;
	eomFragA _eomFragA, RETURN;


% SUBROUTINE eomModifyWakeupReasons ********************
	This subroutine gets the current wakeup reasons word from the CSB and OR's into it the
		value in T, then puts it back.
% ********************

eomModifyWakeupReasons:
		*Fetch the wakeup mask and wakeup reasons into eomTemp and eomTemp1
		*respectively.
	PFETCH2[eomCsbBaseLo,eomTemp,wakeupMaskOffset];
		*Use eomImageXferOffset as a temporary and load it with the register
		*address in emulator space where the naked notify needs to go.
	eomImageXferOffset _ IP[NWW]C;
		*Or the new wakeup reason into the current wakeup reasons word.
	eomTemp1 _ (eomTemp1) OR T, LOADPAGE[eomHiTaskPage];
		*Save the current stack pointer in T.  This is actually the ones complement
		*of the 8 bit value.  Branch to high task page.
	T _ STKP, GOTO[eomLoEntryModifyWakeupReasons];


% SUBROUTINE eomActivateHiTaskFromLoTask ********************
	This subroutine checks to see if the hi task is active, and if not it activates it.
% ********************

eomActivateHiTaskFromLoTask:
		*Check if the high task is already active and if not, activate it.
	GOTO[eomHiTaskActive, R ODD], eomState _ (eomState) OR (hiTaskRunning);
		*Set up the pause remove command word.
	eomFragA _ (hiTaskUnPause);
		*Send the pause remove.
	OUTPUT[eomFragA,loTaskCommandReg], GOTO[eomInterlockOUTPUT];
eomHiTaskActive:
eomLoTaskSwitch:
	NOP, RETURN;



% SUBROUTINE eomInitNewList ********************
	This subroutine initializes the new list ring parameters.
% ********************

eomInitNewList:
		*lowest read transfer will be at 60B (increments by 20B)
	eomNewListRead _ (newListReadRingBase);
		*lowest write transfer will be at 60B (increments by 4)
	eomNewListWrite _ (newListWriteRingBase);
		*Indicate no parameter blocks in the new list (-1).
	eomNewBlocksFull _ (ZERO) - 1, RETURN;


:END[EOMLoTask];
(1795)\f5