//BUGBUG: Data break is not excluded on any model.
//BUGBUG: Implement PDP-5 slowdown.
//BUGBUG: Implement PDP-8/S slowdown.
//BUGBUG: Memory maximums for 8/L, etc. are not implemented.
//BUGBUG: Special non-existant memory behaviors for straight-8, LINC-8.
//BUGBUG: Implement memory protect feature for the 8/L.
//BUGBUG: Implement special nop CIF/CDF for the 8/L.
//BUGBUG: Debug LINC I/O instructions.
//BUGBUG: Distinguish LINC-8 and PDP-12 LINC instruction emulations.
//BUGBUG: Implement LINC peripherals.
//BUGBUG: Implement PDP-12 API/stack stuff.
//BUGBUG: Restrict pre-Omnibus IOT handling for non-TTY devices.
//BUGBUG: Implement special 8/A handling for line printer port.
//BUGBUG: Implement special 8/A handling for memory over 32K.
//BUGBUG: Implement special 8/A handling for PUSH/POP.
//BUGBUG: Implement special VT78 handling for panel memory.
//BUGBUG: Implement special DECmate handling for panel memory.
//BUGBUG: Suppress EAE on PDP-5?, 8/S, 8/L.
//BUGBUG: Suppress EAE on 8/A (except CLA, MQA, MQL, SWP).
//BUGBUG: Suppress EAE on DECmates (illegal instructions).
//BUGBUG: Implement special VT78, DECmate handling for PUSH/POP.
//BUGBUG: Implement VT78, DECmate peripherals.
//BUGBUG: Implement DECmate color graphics option.
//BUGBUG: Implement DECmate Z80 option.
//BUGBUG: Implement DECmate 8086 option.

//   Model        Limitations
//   5            No IAC rotate, no CMA rotate, no EAE, 4K maximum, slower
//                PC at 0000, Interrupts at 0001, no DMA (data break)
//   8/S          No IAC rotate, no CMA rotate, no EAE, 8K maximum, 15x slower
//   (straight) 8 No IAC rotate, IOT 6004 is special, no SWP, no SCL
//                Nonexistent memory reference is special
//   LINC-8       Like straight-8, but with LINC & LINC peripherals, 4K
//   8/L          group 3 CLA is NOP, no EAE, 8K maximum, protect switch
//                CDF/CIF to non-existant field is a NOP
//                RAL RAR and RTL RTR, perform both AND results
//   8/I          RAL RAR and RTL RTR, perform both AND results
//   PDP-12       Same as 8/I, but with LINC & LINC peripherals
//                IOT 6006 is special, DTLA conflicts with PUSHJ
//   8/E/F/M      CAF, BSW, Omnibus I/O, MQL, MQA, SWP
//                Odd semantics for RAL RAR, RTL RTR
//                EAE option has mode B
//   8/A          CAF, BSW, Omnibus I/O, PUSH/POP, 128K support
//                Yet different semantics for RAL RAR, no EAE
//                non-standard LPT
//   VT78         CAF, BSW, Omnibus I/O, PUSH/POP
//                RAL RAR and RTL RTR are NOPs
//                Autoindex suppressed for current page accesses
//                The IF is only 2 bits long (16K)
//                The MMU reads only 2 bits of DF during RDF
//                The MMU maps DF 7 onto panel memory
//                No restart from HLT, No DMA (data break)
//   DECmates     CAF, BSW, R3L, Omnibus I/O, PUSH/POP
//                RAL RAR is R3L, RTL RTR is NOP
//                No EAE, EAE operations hang
//                Incompatible second serial port (also model dependent)
//                KSF, TSF, PSF implementation botched
//                No restart from HLT in DECmate I
//                Color graphics options
//                Optional Z80 and 8086 coprocessor
//
//   Most of these differences have to do with the treatment of IOT and OPR
//   instructions.  There is a difference in the treatment of non-existant
//   memory, and of current page indirection where the current page is page
//   zero.  Quirks that are not fully implemented will be marked in the code
//   with BUGBUG: or TODO: comments, based on the percieved serverity of the
//   limitation imposed by their absence.


/
/ Start in the usual place, and make a preliminary determination of the
/ CPU model.
*200
WHAT,	TAD 0
	TAD (-.
	SNA CLA
	TAD 0
	TAD (-.
	SNA CLA
	JMP PDP5
/ If it can IAC RAL, then it's not made out of [RSB] series modules,
/ Which makes it an 8/L or better.
	CLA IAC RAL
	TAD (-2
	SNA CLA
	JMP TTL
/TODO

/
/ New enough that it isn't made of resistors and transistors.
/ Maybe it is an 8/L?
TTL,	CLA CMA		/Get non-zero value
	CLA 0401	/Try a group 3 CLA
	SNA CLA		/Is this an 8/L?
	JMP PDP8L	/It seems so.
/PDP-8/I or better.
	
/TODO

/
/ It seems to be a PDP-5.  Let's see if it really is.
PDP5,
/TODO
/
/ It seems to be a PDP-8/S.  Let's see if it really is.
PDP8S,
/TODO
/
/ It seems to be a straight-8.  Let's see if it really is.
PDP8,
/TODO
/
/ It seems to be a LINC-8.  Let's see if it really is.
LINC8,
/TODO
/
/ It seems to be a PDP-8/L.  Let's see if it really is.
PDP8L,
/TODO
/
/ It seems to be a PDP-8/I.  Let's see if it really is.
PDP8I,
/TODO
/
/ It seems to be a PDP-.  Let's see if it really is.
PDP812,
/TODO
/
/ It seems to be a PDP-8/E/F/M.  Let's see if it really is.
PDP8E,
/TODO
/
/ It seems to be a PDP-8/A.  Let's see if it really is.
PDP8A,
/TODO
/
/ It seems to be a VT78.  Let's see if it really is.
VT78,
/TODO
/
/ It seems to be a DECmate I.  Let's see if it really is.
DMI,
/TODO
/
/ It seems to be a DECmate II.  Let's see if it really is.
DMII,
/TODO
/
/ It seems to be a DECmate III.  Let's see if it really is.
DMIII,
/TODO

	HLT
$