vax: Minor disassembly refinements

* xtal.cpp: Add value for later use

Author: ajrhacker

src/devices/cpu/vax/vaxdasm.cpp

@@ -928,7 +928,6 @@ offs_t vax_disassembler::disassemble_inst(std::ostream &stream, const vax_disass
 					else switch (inst.operand[n])
 					{
 					case mode::rb:
-					case mode::ab: // Immediate bytes may be used as MOVCn sources, at least with a length of 0
 						format_immediate(stream, opcodes.r8(pc++));
 						break;
 
@@ -938,6 +937,7 @@ offs_t vax_disassembler::disassemble_inst(std::ostream &stream, const vax_disass
 						break;
 
 					case mode::urb:
+					case mode::ab: // Immediate bytes may be used as MOVCn sources, at least with a length of 0
 						util::stream_format(stream, "#^X%02X", opcodes.r8(pc++));
 						break;
 
@@ -999,7 +999,7 @@ offs_t vax_disassembler::disassemble_inst(std::ostream &stream, const vax_disass
 						break;
 
 					case mode::ro: case mode::uro:
-						util::stream_format(stream, "#^X%016X%016X", opcodes.r64(pc), opcodes.r64(pc + 4));
+						util::stream_format(stream, "#^X%016X%016X", opcodes.r64(pc + 8), opcodes.r64(pc));
 						pc += 16;
 						break;
 

src/emu/xtal.cpp

@@ -505,6 +505,7 @@ const double XTAL::known_xtals[] = {
 	 66'666'700, // 66.6667_MHz_XTAL       Later Midway games
 	 67'737'600, // 67.7376_MHz_XTAL       PSX-based h/w, Sony ZN1-2-based
 	 68'850'000, // 68.85_MHz_XTAL         Wyse WY-50
+	 69'196'800, // 69.1968_MHz_XTAL       DEC VCB0x/VAXstation dot clock
 	 69'551'990, // 69.55199_MHz_XTAL      Sharp X68000 31.5kHz video
 	 72'000'000, // 72_MHz_XTAL            Aristocrat MKV
 	 72'576'000, // 72.576_MHz_XTAL        Centipede, Millipede, Missile Command, Let's Go Bowling "Multipede"