282 lines
8.6 KiB
Objective-C
282 lines
8.6 KiB
Objective-C
/*
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* PDP-8/E Simulator
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*
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* Copyright © 1994-2015 Bernhard Baehr
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*
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* Disassembler.m - Disassembler for PDP-8/E instructions
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*
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* This file is part of PDP-8/E Simulator.
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*
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* PDP-8/E Simulator is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#import <Cocoa/Cocoa.h>
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#import "Disassembler.h"
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#import "Unicode.h"
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#import "PDP8.h"
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@implementation Disassembler
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+ (Disassembler *) sharedDisassembler
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{
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static Disassembler *sharedDisassembler;
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if (! sharedDisassembler)
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sharedDisassembler = [[self alloc] init];
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return sharedDisassembler;
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}
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- (id) init
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{
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NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:
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[[NSBundle mainBundle] pathForResource:@"disassembler" ofType:@"plist"]];
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self = [super init];
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mriOpcodes = [[dict objectForKey:@"MRI"] retain];
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iotOpcodes = [[dict objectForKey:@"IOT"] retain];
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oprGroup1Opcodes = [[dict objectForKey:@"OPR Group 1"] retain];
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oprGroup2Opcodes = [[dict objectForKey:@"OPR Group 2"] retain];
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eaeModeAOpcodes = [[dict objectForKey:@"EAE Mode A"] retain];
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eaeModeBOpcodes = [[dict objectForKey:@"EAE Mode B"] retain];
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return self;
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}
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- (NSString *) disassembleOpcodeForPDP8:(PDP8 *)pdp8
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atAddress:(int)addr showOperandsAtPC:(BOOL)showOpAtPC
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{
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short inst, word1, word2, ad, d, e, pc, field;
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char str[128], *p;
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NSCAssert1 ((addr & ~077777) == 0, @"Bad address %o", addr);
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if (addr >= [pdp8 memorySize])
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return NSLocalizedString(@"n/a", @"");
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p = str;
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pc = [pdp8 getProgramCounter];
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inst = [pdp8 memoryAt:addr];
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word1 = [pdp8 memoryAtNext:addr];
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switch (inst & 07000) {
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case 00000 : /* AND */
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case 01000 : /* TAD */
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case 02000 : /* ISZ */
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case 03000 : /* DCA */
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case 04000 : /* JMS */
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case 05000 : /* JMP */
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[[mriOpcodes objectAtIndex:(inst >> 9)]
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getCString:p maxLength:(sizeof(str) - 1) encoding:NSASCIIStringEncoding];
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p += strlen(p);
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p += sprintf(p, " %s", (inst & 0400) ? "I " : "");
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ad = ((inst & 0200) ? (addr & 07600) : 0) | (inst & 0177);
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d = ad - (addr & 07777);
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if (inst >= 04000 && ! (inst & 0400)) {
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if (d == 0)
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p += sprintf(p, ".");
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else if (-5 < d && d < 5)
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p += sprintf(p, ".%+d" /* %d (not %o) to get sign */, d);
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else
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p += sprintf(p, "%o", ad);
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} else
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p += sprintf(p, "%o", ad);
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if (addr == pc && showOpAtPC) {
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field = ((inst >= 04000 && ! (inst & 0400) && [pdp8 getIB] != [pdp8 getIF]) ?
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[pdp8 getIB] : [pdp8 getIF]) << 12;
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d = ((inst & 0400) && ad > 07 && ad < 020) ? 1 : 0;
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/* indirect auto index register access */
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word1 = field | ad;
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ad = ([pdp8 memoryAt:(field | ad)] + d) & 07777;
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if (inst < 05000 || inst >= 05400)
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p += sprintf(p, " (%4.4o)", ad);
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if (inst < 05000 && (inst & 0400)) {
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field = ((inst < 04000) ? [pdp8 getDF] : [pdp8 getIB]) << 12;
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d = (d && word1 == (field | ad)) ? 1 : 0;
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ad = ([pdp8 memoryAt:(field | ad)] + d) & 07777;
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p += sprintf(p, " ((%4.4o))", ad);
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}
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}
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break;
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case 06000 : /* IOT */
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[[iotOpcodes objectAtIndex:(inst & 0777)]
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getCString:p maxLength:sizeof(str) encoding:NSASCIIStringEncoding];
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p += strlen(p);
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break;
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case 07000 : /* OPR */
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switch (inst & 07401) {
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case 07000 : /* OPR Group I */
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case 07001 :
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[[oprGroup1Opcodes objectAtIndex:(inst & 0377)]
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getCString:p maxLength:sizeof(str) encoding:NSASCIIStringEncoding];
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p += strlen(p);
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break;
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case 07400 : /* OPR Group II */
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[[oprGroup2Opcodes objectAtIndex:((inst & 0377) >> 1)]
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getCString:p maxLength:sizeof(str) encoding:NSASCIIStringEncoding];
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p += strlen(p);
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break;
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/*
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* | | | |
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* |---|---|---|---|---|---|---|---|---|
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* | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10| 11|
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* | 1 |CLA|MQA|SCA|MQL| | | | 1 | Group III Mode A
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* |---|---|---|---|---|---|---|---|---|
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* Sequence: 1 2 2 \____3____/
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* V
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* 0 = NOP 2 = MUY# 4 = NMI 6 = ASR#
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* 1 = SCL# 3 = DVI# 5 = SHL# 7 = LSR#
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*
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* | | | |
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* |---|---|---|---|---|---|---|---|---|
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* | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10| 11|
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* | 1 |CLA|MQA| |MQL| | | | 1 | Group III Mode B
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* |---|---|---|---|---|---|---|---|---|
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* Sequence: 1 2 \ 2 /
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* \_______3_______/
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* V
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* 0 = NOP 4 = NMI 10 = SCA 14 = DPSZ
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* 1 = ACS 5 = SHL# 11 = DAD# 15 = DPIC*
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* 2 = MUY# 6 = ASR# 12 = DST# 16 = DCM*
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* 3 = DVI# 7 = LSR# 13 = SWBA 17 = SAM
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* # = 2-word instructions
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* * = (MQL & MQA must be set)
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*/
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case 07401 : /* EAE */
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d = (inst & 0377) >> 1 ;
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if ([pdp8 getEAEmode] == EAE_MODE_A) {
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[[eaeModeAOpcodes objectAtIndex:d]
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getCString:p maxLength:sizeof(str) encoding:NSASCIIStringEncoding];
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p += strlen(p);
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switch (inst & 016) {
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case 002 : /* SCL */
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case 004 : /* MUY */
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case 006 : /* DVI */
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case 012 : /* SHL */
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case 014 : /* ASR */
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case 016 : /* LSR */
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if (inst != 07447) { /* SWBA */
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p += sprintf(p, " %o", word1);
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/* word1 is operand */
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}
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break;
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default :
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break;
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}
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} else { /* EAE mode B */
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[[eaeModeBOpcodes objectAtIndex:d]
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getCString:p maxLength:sizeof(str) encoding:NSASCIIStringEncoding];
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p += strlen(p);
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switch (inst & 056) {
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case 04 : /* MUY */
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case 06 : /* DVI */
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p += sprintf(p, " %o", word1);
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/* DF|word1 points to operand word */
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if (addr == pc && showOpAtPC) {
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ad = (addr & 070000) | ((addr + 1) & 07777);
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d = ((ad & 07770) == 010) ? 1 : 0; /* autoindex? */
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word1 = ([pdp8 getDF] << 12) | ((word1 + d) & 07777);
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d = (d && (ad == word1)) ? 1 : 0;
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/* operand == autoindexed ptr? */
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p += sprintf(p, " (%4.4o)",
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([pdp8 memoryAt:word1] + d) & 07777);
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}
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break;
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case 012 : /* SHL */
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case 014 : /* ASR */
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case 016 : /* LSR */
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p += sprintf(p, " %o", word1);
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/* word1 is operand */
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break;
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case 042 : /* DAD */
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case 044 : /* DST */
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p += sprintf(p, " %o", word1);
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/* DF|word1 points to op double word */
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/* DAD adds op double word to AC'MQ */
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/* DST overwrites op dword with AC'MQ */
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if (addr == pc && showOpAtPC) {
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ad = (addr & 070000) | ((addr + 1) & 07777);
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d = ((ad & 07770) == 010) ? 1 : 0; /* autoindex? */
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word2 = ([pdp8 getDF] << 12) | ((word1 + d + 1) & 07777);
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word1 = ([pdp8 getDF] << 12) | ((word1 + d) & 07777);
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e = (d && (ad == word2)) ? 1 : 0;
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/* operand == autoindexed ptr? */
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d = (d && (ad == word1)) ? 1 : 0;
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p += sprintf(p, " (%4.4o%4.4o)",
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([pdp8 memoryAt:word2] + e) & 07777,
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([pdp8 memoryAt:word1] + d) & 07777);
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}
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break;
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}
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}
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break;
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}
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break;
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}
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*p = '\0'; /* to avoid Xcode analyzer warning */
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return [NSString stringWithCString:str encoding:NSASCIIStringEncoding];
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}
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- (NSString *) operandInfoForPDP8:(PDP8 *)pdp8 atAddress:(int)addr
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{
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NSMutableString *string;
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int inst, op, ad, oldad, field, d, d1, mark, i;
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inst = [pdp8 memoryAt:addr];
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if (inst >= 06000)
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return nil; /* no MRI */
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if (05000 <= inst && inst < 05400)
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return nil; /* direct JMP */
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ad = ((inst & 0200) ? (addr & 07600) : 0) | (inst & 0177);
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d = ((inst & 0400) && ad > 07 && ad < 020) ? 1 : 0; /* indirect auto index register access */
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ad |= addr & 070000;
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op = ([pdp8 memoryAt:ad] + d) & 07777;
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string = [NSMutableString stringWithFormat:@"%5.5o: %4.4o", ad, op];
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if (inst < 05000 && (inst & 0400)) {
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[string appendString:@"\n\n"];
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oldad = ad;
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ad = op;
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mark = ((inst < 04000) ? [pdp8 getDF] : [pdp8 getIB]) << 12;
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for (i = 0; i < 4; i++) {
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field = i << 12;
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part2 :
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d1 = (d && oldad == (field | ad)) ? 1 : 0;
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op = ([pdp8 memoryAt:field | ad] + d1) & 07777;
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[string appendFormat:@"%5.5o: %4.4o", field | ad, op];
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if (field == mark)
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[string appendFormat:@"%C", UNICODE_DIAMOND];
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if (field & 040000)
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[string appendString:@"\n"];
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else {
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[string appendString:@"\t"];
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field |= 040000;
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goto part2;
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}
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}
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}
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return string;
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}
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- (void) addMnemonic:(NSString *)mnemonic forIOT:(int)opcode
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{
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NSAssert1 ((opcode & ~00777) == 06000, @"Invalid IOT %o", opcode);
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[iotOpcodes replaceObjectAtIndex:opcode & 0777 withObject:mnemonic];
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}
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@end
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