*-----------------------------------------------------------
Title[DMesaMiscDisp.mc...January 21, 1982 4:27 PM...Gene];
* Dispatch tables for all MISC opcodes, and definitions of undefined MISC opcodes.
*-----------------------------------------------------------

%
There are 400B MISC opcodes, divided into 20B groups of 20B each.

The entry point for each MISC opcode is declared by including the clause
MiscTable[xxx]
in the first microinstruction of the code implementing opcode xxx.

Upon entry, T contains TOS (if there is one) and StkP has been advanced
in preparation for pushing a result. Routines that do not push a result
must decrement StkP. Exit is via the usual IFUNextN.

All unimplemented MISC opcodes cause a trap to occur. In Alto mode,
a KFCB[sUnimplemented] is executed. (Exception: floating point opcodes trap
by putting the offending opcode in OTPReg and executing a KFCB[137B].)

In PrincOps mode, a Cedar opcode trap is executed if an OpTrapTable has been
set up; otherwise a standard PrincOps TrapZero[sUnimplemented] is executed.
(See DMesaFaults.mc for more details.) The microcode implementing a MISC
opcode may conditionally trap (e.g., for illegal arguments) by branching
to MiscOpcodeTrap.

Adding or removing MISC opcodes requires changing the dispatch tables.
This is why these tables are in a separate file, which may be renamed and
edited when non-standard MISC opcodes are introduced.

To add a new MISC opcode to an existing group, delete the statement
MiscOpcodeUnimplemented[xxx];
below, and add the corresponding
MiscTable[xxx]
in the appropriate source file.

To add a new group of MISC opcodes, change
MiscGroupUnimplemented[xxx];
to:MiscGroupImplemented[xxx];
below, where xxx is the first opcode of the group (i.e., a multiple of 20B).
Then, for each opcode in the group NOT being defined, add the statement
MiscOpcodeUnimplemented[xxx];

Note: the MiscOpcodeUnimplemented[xxx] statments may appear either below or in
another source file. They appear below when the unimplemented opcodes in
a group are unrelated, but in a separate source file when they are related to
other opcodes that are implemented in that source file.
%

TopLevel;
Set[XTask, IP[EMU]];

*-----------------------------------------------------------
* First-level (group) dispatch table:
*-----------------------------------------------------------

M[MiscGroupImplemented,
(T← StackNoUfl&+1, BranchExternal[Or[
Select[RShift[#1, 6], MT0Loc, MT1Loc, MT2Loc, MT3Loc],
1]])];
M[MiscGroupUnimplemented, (Branch[Misc377])];

MiscDispatch: DispTable[20],
MiscGroupImplemented[000];* Miscellaneous operations
MiscGroupImplemented[020];* Floating point
MiscGroupUnimplemented[040];
:If[AltoMode];********** Alto version **********
MiscGroupUnimplemented[060];
:Else;******** PrincOps version ********
MiscGroupImplemented[060];* Cedar allocator/GC
:EndIf;**********************************
MiscGroupUnimplemented[100];
MiscGroupUnimplemented[120];
MiscGroupUnimplemented[140];
MiscGroupUnimplemented[160];
MiscGroupUnimplemented[200];
MiscGroupUnimplemented[220];
MiscGroupImplemented[240];* Dorado-only operations
MiscGroupUnimplemented[260];
MiscGroupUnimplemented[300];
MiscGroupUnimplemented[320];
MiscGroupUnimplemented[340];
MiscGroupUnimplemented[360];

*-----------------------------------------------------------
* Unimplemented MISC opcodes:
*-----------------------------------------------------------

:If[AltoMode];********** Alto version **********
MiscOpcodeUnimplemented[002];* Read RAM
MiscOpcodeUnimplemented[004];* IO reset
MiscOpcodeUnimplemented[010];* Set maintenance panel
MiscOpcodeUnimplemented[014];* XferL
MiscOpcodeUnimplemented[015];* TextBlt

*MiscOpcodeUnimplemented[244];*Used by music
*MiscOpcodeUnimplemented[245];*Used by music
MiscOpcodeUnimplemented[247];* ResetEther
MiscOpcodeUnimplemented[250];* Boot
MiscOpcodeUnimplemented[253];
MiscOpcodeUnimplemented[254];
MiscOpcodeUnimplemented[255];
MiscOpcodeUnimplemented[256];
MiscOpcodeUnimplemented[257];

:Else;******** PrincOps version ********
MiscOpcodeUnimplemented[002];* Read RAM
MiscOpcodeUnimplemented[004];* IO reset
MiscOpcodeUnimplemented[014];* XferL
MiscOpcodeUnimplemented[015];* TextBlt
MiscOpcodeUnimplemented[017];* Set default partition

MiscOpcodeUnimplemented[244];
MiscOpcodeUnimplemented[245];
MiscOpcodeUnimplemented[253];
MiscOpcodeUnimplemented[254];
MiscOpcodeUnimplemented[255];
MiscOpcodeUnimplemented[256];
MiscOpcodeUnimplemented[257];
:EndIf;**********************************


* Special entry to squash pending dispatch when an entire
* group is unimplemented.
Misc377:
MiscOpcodeUnimplemented[377];


* This doesn’t really belong here, but...
* Cedar opcodes no longer defined in Alto/Mesa system:
:If[AltoMode];********** Alto version **********
UndefOp[MOpWCLB];
UndefOp[MOpICLB];
:EndIf;**********************************