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-rw-r--r--io/model.cpp2
-rw-r--r--isa/decode.cpp76
-rw-r--r--main.cpp2
-rw-r--r--programs/count.pal2
-rw-r--r--programs/mike_fib.pal117
5 files changed, 188 insertions, 11 deletions
diff --git a/io/model.cpp b/io/model.cpp
index dd55ce6..eaa6ca8 100644
--- a/io/model.cpp
+++ b/io/model.cpp
@@ -18,7 +18,7 @@ bool iomodel::interact(std::array<unsigned int, NUM_CTLREGS> &ctlregs) {
18 18
19 if (ctlregs[TT_OUTPUT] & 0x100) { 19 if (ctlregs[TT_OUTPUT] & 0x100) {
20 // PDP-8 doesn't really have support for 8-bit output, this is Jules' contribution 20 // PDP-8 doesn't really have support for 8-bit output, this is Jules' contribution
21 std::cout << (char)((ctlregs[TT_OUTPUT] & 0xff) ^ 0x80); 21 std::cout << (char)((ctlregs[TT_OUTPUT] & 0xff) ^ 0x80) << std::flush;
22 ctlregs[TT_OUTPUT] &= ~0x1ff; 22 ctlregs[TT_OUTPUT] &= ~0x1ff;
23 log.emplace(time + TT_OUTPUT_DELAY, event(TT_OUTPUT, 0x200, 0)); 23 log.emplace(time + TT_OUTPUT_DELAY, event(TT_OUTPUT, 0x200, 0));
24 } 24 }
diff --git a/isa/decode.cpp b/isa/decode.cpp
index d24632b..cb6a694 100644
--- a/isa/decode.cpp
+++ b/isa/decode.cpp
@@ -23,7 +23,7 @@ instruction_context decode(unsigned int dfifb, unsigned int pc, unsigned int bit
23 inst.need_read_acc = true; 23 inst.need_read_acc = true;
24 inst.need_write_acc = true; 24 inst.need_write_acc = true;
25 inst.ef = [](auto &ctx) { 25 inst.ef = [](auto &ctx) {
26 ctx.acc = ctx.acc.value() & ctx.data.value(); 26 ctx.acc = ctx.acc.value() & ctx.data.value() & 07777;
27 }; 27 };
28 break; 28 break;
29 case 1: // TAD 29 case 1: // TAD
@@ -44,7 +44,7 @@ instruction_context decode(unsigned int dfifb, unsigned int pc, unsigned int bit
44 inst.possibly_redirects = true; 44 inst.possibly_redirects = true;
45 inst.ef = [](auto &ctx) { 45 inst.ef = [](auto &ctx) {
46 ctx.data = (ctx.data.value() + 1) & 07777; 46 ctx.data = (ctx.data.value() + 1) & 07777;
47 if (*ctx.data) 47 if (*ctx.data == 0)
48 ctx.next_pc = (ctx.next_pc & ~07777) | ((ctx.next_pc + 1) & 07777); 48 ctx.next_pc = (ctx.next_pc & ~07777) | ((ctx.next_pc + 1) & 07777);
49 }; 49 };
50 break; 50 break;
@@ -72,9 +72,69 @@ instruction_context decode(unsigned int dfifb, unsigned int pc, unsigned int bit
72 }; 72 };
73 break; 73 break;
74 case 6: // IOT 74 case 6: // IOT
75 inst.ef = [](auto &ctx) { 75 switch ((bits >> 3) & 077) {
76 assert(false); 76 case 004:
77 }; 77 switch (bits & 07) {
78 case 0:
79 inst.write_ctlreg = TT_OUTPUT;
80 inst.ef = [](auto &ctx) {
81 ctx.ctlval = 0x600;
82 };
83 break;
84 case 1:
85 inst.read_ctlreg = TT_OUTPUT;
86 inst.possibly_redirects = true;
87 inst.ef = [](auto &ctx) {
88 if (ctx.ctlval.value() & 0x200)
89 ctx.next_pc = (ctx.next_pc & ~07777) | ((ctx.next_pc + 1) & 07777);
90 };
91 break;
92 case 2:
93 inst.write_ctlreg = TT_OUTPUT;
94 inst.ef = [](auto &ctx) {
95 ctx.ctlval = 0;
96 };
97 break;
98 case 4:
99 inst.need_read_acc = true;
100 inst.read_ctlreg = TT_OUTPUT;
101 inst.write_ctlreg = TT_OUTPUT;
102 inst.ef = [](auto &ctx) {
103 auto &x = ctx.ctlval.value();
104 x &= ~0x1ff;
105 x |= (ctx.acc.value() & 0xff) ^ 0x80; // 0x7f instead of 0xff for real PDP-8 IO
106 x |= 0x100;
107 };
108 break;
109 case 5:
110 inst.possibly_redirects = true;
111 // FIXME this instruction wants to read both TT_OUTPUT and TT_INPUT
112 inst.ef = [](auto &ctx) {
113 assert(false);
114 };
115 break;
116 case 6:
117 inst.need_read_acc = true;
118 inst.read_ctlreg = TT_OUTPUT;
119 inst.write_ctlreg = TT_OUTPUT;
120 inst.ef = [](auto &ctx) {
121 auto &x = ctx.ctlval.value();
122 x &= ~0x7ff;
123 x |= (ctx.acc.value() & 0xff) ^ 0x80;
124 x |= 0x100;
125 };
126 break;
127 default:
128 inst.ef = [](auto &ctx) {
129 assert(false);
130 };
131 }
132 break;
133 default:
134 inst.ef = [](auto &ctx) {
135 assert(false);
136 };
137 }
78 break; 138 break;
79 case 7: // OPR 139 case 7: // OPR
80 if ((bits & 0400) == 0000) { 140 if ((bits & 0400) == 0000) {
@@ -93,7 +153,7 @@ instruction_context decode(unsigned int dfifb, unsigned int pc, unsigned int bit
93 inst.ef = [cla, cll, cma, cml, rar, ral, bsw, iac](auto &ctx) { 153 inst.ef = [cla, cll, cma, cml, rar, ral, bsw, iac](auto &ctx) {
94 if (cla) ctx.acc = 0; 154 if (cla) ctx.acc = 0;
95 if (cll) ctx.link = 0; 155 if (cll) ctx.link = 0;
96 if (cma) ctx.acc = ~ctx.acc.value(); 156 if (cma) ctx.acc = ~ctx.acc.value() & 07777;
97 if (cml) ctx.link = !ctx.link.value(); 157 if (cml) ctx.link = !ctx.link.value();
98 if (iac) { 158 if (iac) {
99 if (++ctx.acc.value() == 0) ctx.link = !ctx.link.value(); 159 if (++ctx.acc.value() == 0) ctx.link = !ctx.link.value();
@@ -139,7 +199,7 @@ instruction_context decode(unsigned int dfifb, unsigned int pc, unsigned int bit
139 assert(!osr); 199 assert(!osr);
140 if (hlt) ctx.ctlval = 1; 200 if (hlt) ctx.ctlval = 1;
141 if (skip) 201 if (skip)
142 ctx.next_pc = (ctx.next_pc & 070000) | ((ctx.next_pc + 1) & 007777); 202 ctx.next_pc = (ctx.next_pc & ~07777) | ((ctx.next_pc + 1) & 07777);
143 }; 203 };
144 } else if ((bits & 0411) == 0410) { 204 } else if ((bits & 0411) == 0410) {
145 bool cla = bits & 0200; 205 bool cla = bits & 0200;
@@ -163,7 +223,7 @@ instruction_context decode(unsigned int dfifb, unsigned int pc, unsigned int bit
163 assert(!osr); 223 assert(!osr);
164 if (hlt) ctx.ctlval = 1; 224 if (hlt) ctx.ctlval = 1;
165 if (skip) 225 if (skip)
166 ctx.next_pc = (ctx.next_pc & 070000) | ((ctx.next_pc + 1) & 007777); 226 ctx.next_pc = (ctx.next_pc & ~07777) | ((ctx.next_pc + 1) & 07777);
167 }; 227 };
168 } else if ((bits & 0401) == 0401) { 228 } else if ((bits & 0401) == 0401) {
169 bool cla = bits & 0200; 229 bool cla = bits & 0200;
diff --git a/main.cpp b/main.cpp
index b587ce4..46be782 100644
--- a/main.cpp
+++ b/main.cpp
@@ -66,7 +66,7 @@ int main(int argc, const char *argv[]) {
66 } 66 }
67 67
68 while (true) { 68 while (true) {
69 std::cout << fmt::format("{:9} @{:04o} {:01o}:{:04o}:{:04o}\n", system.time, checker.pc, checker.link, checker.acc, checker.mq); 69 //std::cout << fmt::format("{:9} @{:04o} {:01o}:{:04o}:{:04o} TTO={:x}\n", system.time, checker.pc, checker.link, checker.acc, checker.mq, checker.ctlregs[TT_OUTPUT]);
70 checker.execute(); 70 checker.execute();
71 } 71 }
72 72
diff --git a/programs/count.pal b/programs/count.pal
index 2e96759..aa34be6 100644
--- a/programs/count.pal
+++ b/programs/count.pal
@@ -2,5 +2,5 @@
2 2
3*200 3*200
4 4
5LOOP, TAD [1] 5LOOP, TAD (1)
6 JMP LOOP 6 JMP LOOP
diff --git a/programs/mike_fib.pal b/programs/mike_fib.pal
new file mode 100644
index 0000000..6f56109
--- /dev/null
+++ b/programs/mike_fib.pal
@@ -0,0 +1,117 @@
1 *200
2MAIN, CLA
3 TAD (-26)
4 DCA FIBN
5 DCA FIB0
6 IAC
7 DCA FIB1
8LOOP, CLA
9 TAD FIB0
10 JMS PUTN
11 CLA
12 TAD (054)
13 JMS PUTC
14 CLA
15 TAD FIB0
16 TAD FIB1
17 DCA FIB2
18 TAD FIB1
19 DCA FIB0
20 TAD FIB2
21 DCA FIB1
22 ISZ FIBN
23 JMP LOOP
24EXIT, HLT
25 CLA IAC
26 DCA FIB1
27 DCA FIB0
28 JMP MAIN
29PUTN, 0
30 JMS ITOA
31 CMA IAC
32 IAC
33 CMA IAC
34 DCA 10
35PUTNL, CLA
36 TAD I 10
37 SPA
38 JMP I PUTN
39 TAD (60)
40 JMS PUTC
41 JMP PUTNL
42PUTC, 0
43 TLS
44 TSF
45 JMP .-1
46 JMP I PUTC
47ITOA, 0
48 DCA ITOAV
49 DCA ITOAD
50 DCA ITOAD+1
51 DCA ITOAD+2
52 DCA ITOAD+3
53 TAD (-14)
54 DCA ITOAN
55ITOAL, CLL / LOOP OVER BINARY INPUT BITS
56 TAD ITOAD+3
57 JMS ITOA2X
58 DCA ITOAD+3
59 TAD ITOAD+2
60 JMS ITOA2X
61 DCA ITOAD+2
62 TAD ITOAD+1
63 JMS ITOA2X
64 DCA ITOAD+1
65 TAD ITOAD
66 JMS ITOA2X
67 DCA ITOAD
68 CLL
69 TAD ITOAV / SHIFT MSB OUT OF INPUT VALUE
70 RAL
71 DCA ITOAV
72 RAL
73 TAD ITOAD+3 / ADD SHIFTED-OUT MSB TO DECIMAL LSD
74 DCA ITOAD+3
75 ISZ ITOAN
76 JMP ITOAL / NEXT LOOP ITERATION
77 TAD (ITOAD)
78 DCA ITOAR
79ITOAJ, TAD I ITOAR
80 SZA
81 JMP ITOAX
82 ISZ ITOAR
83 TAD I ITOAR
84 SZA
85 JMP ITOAX
86 ISZ ITOAR
87 TAD I ITOAR
88 SZA
89 JMP ITOAX
90 ISZ ITOAR
91ITOAX, CLA
92 TAD ITOAR
93 JMP I ITOA
94ITOA2X, 0
95 RAL / PUTS 0 IN LINK
96 DCA ITOAT
97 TAD (-12)
98 TAD ITOAT / PUTS 1 IN LINK IF WRAPPED
99 SMA
100 DCA ITOAT
101 CLA
102 TAD ITOAT
103 JMP I ITOA2X
104FIB0, 0
105FIB1, 1
106FIB2, 0
107FIBN, -27
108ITOAD, 0 / OUTPUT DIGITS (MSD FIRST)
109 0
110 0
111 0
112 4000 / OUTPUT SENTINEL
113ITOAN, 0 / INPUT BITS LOOP COUNTER
114ITOAR, 0 / POINTER TO FIRST NONZERO DIGIT
115ITOAT, 0 / SCRATCHPAD FOR ITOA2X
116ITOAV, 0 / VALUE BEING CONVERTED (TEMPORARY)
117$
generated by cgit v1.2.3 (git 2.51.0) at 2026-04-18 22:35:10 -0700