Arduino for STM32

PDP-8 on 32F103

Pito
Thu Oct 06, 2016 5:44 pm
I like retrocomputing:
http://jeelabs.org/2016/10/stm32f103-emulating-a-pdp-8/
Runs on YellowPill :)
I would use 110baud instead of less retro 115k2 :)

BTW, if you are a retrocomputing fan and interested in porting RetroBSD or LiteBSD to STM32Fxx platform you may join
http://retrobsd.org/wiki/doku.php

RogerClark
Thu Oct 06, 2016 8:56 pm
Its good to see @jcw is still working on STM32 projects
Pito
Fri Nov 04, 2016 7:20 pm
This is my quick hack – PDP-8 for MapleMini/BluePill under stm32duino :)

// PDP-8 emulator
// -jcw, 2016-08-29
// Modded for STM32duino by Pito 11/2016
// . you need the Serial.printf() hack, hopefully it printfs Octals :)
// http://www.stm32duino.com/viewtopic.php?f=18&t=1014#p12014
// . place "focal.h" file to this pdp8.ino sketch for compilation (focal.h attached)
// . Serial1 used here
// . set Serial to 9600 (I do here with 115k2 but it is too fast, it seems)
// No warranties of any kind..

#include <stdio.h>
typedef unsigned short Word;
int errno, EIO;
int rxData = -1;

int txReady (void) {
return 1;
}

void txSend (char ch) {
while (!txReady()) // not strictly needed for emulation, only for printf
;
Serial1.print(ch);
}

const unsigned char program[] = {
#include "focal.h"
};

#define MEMSIZE 4096

Word pc, mem[MEMSIZE];

static Word mask(Word w) { return w & 07777; }
static Word lmask(Word w) { return w & 017777; }

static Word opAddr (int ir) {
Word a = ir & 0177;
if (ir & 0200)
a |= (pc - 1) & 07600;
if (ir & 0400) {
if ((a & 07770) == 010)
mem[a] = mask(mem[a] + 1);
a = mem[a];
}
return a;
}

static int loader (const unsigned char* ptr) {
Word addr = 0;
Serial1.printf("LOAD");
Word b;
for (;;) {
// read next word
b = *ptr++;
if (b & 0200) // skip run-in
continue;
b = (b << 6) | *ptr++;

// look for run-out, to ignore word before it as being a checksum
int c = *ptr;
if (c & 0200)
break;

// process one word
if (b & 010000) {
if (addr != 0)
Serial1.printf("-%04o", addr - 1);
addr = mask(b);
Serial1.printf(" %04o", addr);
} else
mem[addr++] = b;
}
Serial1.printf("-%04o CHECK %04o\n", mask(addr - 1), mask(b));
return addr;
}

void run () {
if (loader(program) == 0)
return;

pc = 0200;
Word sr = 0;

Word ac = 0, mq = 0;
int iena = 0;
for (;;) {
iena >>= 1; // delayed interrupt enabling, relies on sign extension

static short counter; // HACK: every 1024 ops, we fake an interrupt
if ((iena & 1) && (++counter & 0x03FF) == 0) {
mem[0] = pc;
pc = 1;
iena = 0;
}

int ir = mem[pc];
//if (argc >= 5)
// Serial1.printf("PC %04o IR %04o\r\n", pc, ir);
pc = mask(pc + 1);
switch ((ir >> 9) & 07) {

case 0: // AND
ac &= mem[opAddr(ir)] | 010000;
break;

case 1: // TAD
ac = lmask(ac + mem[opAddr(ir)]);
break;

case 2: { // ISZ
Word t = opAddr(ir);
mem[t] = mask(mem[t] + 1);
if (mem[t] == 0)
pc = mask(pc + 1);
break;
}

case 3: // DCA
mem[opAddr(ir)] = mask(ac);
ac &= 010000;
break;

case 4: { // JMS
Word t = opAddr(ir);
mem[t] = pc;
pc = mask(t + 1);
break;
}

case 5: // JMP
pc = opAddr(ir);
break;

case 6: // IOT
switch ((ir >> 3) & 077) {
case 00:
switch (ir) {
case 06001: iena = ~1; break; // delays one cycle
case 06002: iena = 0; break;
default: Serial1.printf("IOT %04o AC=%04o\r\n", ir, ac);
}
break;
case 03: // keyboard
if (Serial1.available() > 0)
rxData = Serial1.read();

if ((ir & 01) && rxData >= 0) // skip if ready
pc = mask(pc + 1);
if (ir & 04) { // read byte
int b = rxData & 0xFF;
rxData = -1;
ac = (ac & 010000) | b;
}
break;
case 04: // teleprinter
if ((ir & 01) && txReady()) // skip if ready
pc = mask(pc + 1);
if (ir & 04) // send byte
txSend(ac & 0177); // strip off parity
if (ir & 02) // clear flag
ac &= 010000;
break;
default:
//Serial1.printf("IOT %04o AC=%04o\r\n", ir, ac);
break;
}
break;

case 7: // OPR
if ((ir & 0400) == 0) { // group 1
if (ir & 0200) // CLA
ac &= 010000;
if (ir & 0100) // CLL
ac &= 07777;
if (ir & 040) // CMA
ac ^= 07777;
if (ir & 020) // CML
ac ^= 010000;
if (ir & 01) // IAC
ac = lmask(ac + 1);
switch (ir & 016) {
case 012: // RTR
ac = lmask((ac >> 1) | (ac << 12)); // fall through
case 010: // RAR
ac = lmask((ac >> 1) | (ac << 12));
break;
case 06: // RTL
ac = lmask((ac >> 12) | (ac << 1)); // fall through
case 04: // RAL
ac = lmask((ac >> 12) | (ac << 1));
break;
case 02: // BSW
ac = (ac & 010000) | ((ac >> 6) & 077)
| ((ac << 6) & 07700);
break;
}
} else if ((ir & 01) == 0) { // group 2
// SMA, SPA, SZA, SNA, SNL, SZL
int s = ((ir & 0100) && (ac & 04000)) ||
((ir & 040) && (ac & 07777) == 0) ||
((ir & 020) && (ac & 010000) != 0) ? 0 : 010;
if (s == (ir & 010))
pc = mask(pc + 1);
if (ir & 0200) // CLA
ac &= 010000;
if (ir & 04) // OSR
ac |= sr;
if (ir & 02) { // HLT
Serial1.printf("\r\nHALT %04o", mask(ac));
return;
}
} else { // group 3
Word t = mq;
if (ir & 0200) // CLA
ac &= 010000;
if (ir & 020) { // MQL
mq = ac & 07777;
ac &= 010000;
}
if (ir & 0100)
ac |= t;
}
break;
}
}
}

void setup() {
// put your setup code here, to run once:
Serial1.begin(115200);
run();
}

void loop() {
// put your main code here, to run repeatedly:
}

Pito
Fri Nov 04, 2016 8:47 pm
*ERASE ALL
*
* 1.01 C INTRST FROM FOCAL PROGRAMMING MANUAL PDP-15 SYSTEMS
* 1.02 C COPYRIGHT 1970 BY DIGITAL EQUPMENT CORP.
* 1.03 C REPRINTED BY PERMISSION OF DIGITAL EQUIPMENT CORP.
* 1.04 C LAST CHANGE: 8/9/71
* 1.05
* 1.06 C THIS PROGRAM WILL COMPUTE MONTHLY PAYMENTS AND THE
* 1.07 C CONTRIBUTION OF EACH PAYMENT TO INTEREST AND PRINCIPAL.
* 1.08 C YOU WILL BE ASKED THE AMOUNT OF THE PRINCIPAL, THE RATE
* 1.09 C OF THE INTEREST, AND THE TERM OF THE LOAN, WHICH IS IN
* 1.10 C MONTHS. THE PROGRAM WILL THEN OUTPUT A TABLE SHOWING
* 1.11 C THE PROGRESSION OF THE LOAN.
* 1.12
* 1.33 E
* 1.34 A "PRINCIPAL: ",PR,!"INTEREST RATE: ",IN
* 1.35 A !"TERM (IN MONTHS): ",TE,!!
* 1.40 S D=1+((IN/12)*.01)
* 1.41 F A=1,TE;D 15.99
* 1.42 S C=PR/B
* 1.50 S BA=PR
* 5.02 T "PRINCIPAL:",%7.02,PR,:30"PAYMENTS",C,!!!
* 5.05 T :5,"PAYMENT",:17,"INTEREST",:32,"PRINCIPAL",:50,"BALANCE",!
* 6.01 F M=1,TERM;D 7
* 6.02 T !!!,:20,"TOTAL INTEREST",%6.02,TO,!!!;G 1.33
* 7.01 S CI=BA*(IN/12)*.01
* 7.02 S TO=TO+CI
* 7.03 S CP=C-CI;S BA=BA-CP;T %7,M,%14.02,CI,CP,BA,!
*15.99 S B=B+(1/D^A)
*
*
* GO
PRINCIPAL: :100000

INTEREST RATE: :6.3

TERM (IN MONTHS): :120

100000.0= 0.00= 1125.33

= 0.00PAYMENT= 0.00INTEREST= 0.00PRINCIPAL= 0.00BALANCE
= 1= 525.00= 600.33= 99399.70
= 2= 521.85= 603.48= 98796.20
= 3= 518.68= 606.65= 98189.50
= 4= 515.50= 609.84= 97579.70
= 5= 512.29= 613.04= 96966.60
= 6= 509.08= 616.26= 96350.40
= 7= 505.84= 619.49= 95730.90
= 8= 502.59= 622.74= 95108.10
= 9= 499.32= 626.01= 94482.10
= 10= 496.03= 629.30= 93852.80
= 11= 492.73= 632.60= 93220.20
= 12= 489.41= 635.93= 92584.30
= 13= 486.07= 639.26= 91945.00
= 14= 482.71= 642.62= 91302.30
= 15= 479.34= 645.99= 90656.30
= 16= 475.95= 649.39= 90007.00
= 17= 472.54= 652.80= 89354.20
= 18= 469.11= 656.22= 88697.90
= 19= 465.67= 659.67= 88038.20
= 20= 462.20= 663.13= 87375.10
= 21= 458.72= 666.61= 86708.50
= 22= 455.22= 670.11= 86038.40
= 23= 451.70= 673.63= 85364.70
= 24= 448.17= 677.17= 84687.50
= 25= 444.61= 680.72= 84006.80
= 26= 441.04= 684.30= 83322.50
= 27= 437.44= 687.89= 82634.60
= 28= 433.83= 691.50= 81943.10
= 29= 430.20= 695.13= 81248.00
= 30= 426.55= 698.78= 80549.20
= 31= 422.88= 702.45= 79846.80
= 32= 419.20= 706.14= 79140.60
= 33= 415.49= 709.84= 78430.80
= 34= 411.76= 713.57= 77717.20
= 35= 408.02= 717.32= 76999.90
= 36= 404.25= 721.08= 76278.80
= 37= 400.46= 724.87= 75553.90
= 38= 396.66= 728.67= 74825.20
= 39= 392.83= 732.50= 74092.70
= 40= 388.99= 736.34= 73356.40
= 41= 385.12= 740.21= 72616.10
= 42= 381.24= 744.10= 71872.00
= 43= 377.33= 748.00= 71124.00
= 44= 373.40= 751.93= 70372.10
= 45= 369.45= 755.88= 69616.20
= 46= 365.49= 759.85= 68856.30
= 47= 361.50= 763.84= 68092.50
= 48= 357.49= 767.85= 67324.60
= 49= 353.46= 771.88= 66552.70
= 50= 349.40= 775.93= 65776.80
= 51= 345.33= 780.00= 64996.80
= 52= 341.23= 784.10= 64212.70
= 53= 337.12= 788.22= 63424.50
= 54= 332.98= 792.35= 62632.10
= 55= 328.82= 796.51= 61835.60
= 56= 324.64= 800.69= 61034.90
= 57= 320.43= 804.90= 60230.00
= 58= 316.21= 809.12= 59420.90
= 59= 311.96= 813.37= 58607.50
= 60= 307.69= 817.64= 57789.80
= 61= 303.40= 821.93= 56967.90
= 62= 299.08= 826.25= 56141.70
= 63= 294.74= 830.59= 55311.10
= 64= 290.38= 834.95= 54476.10
= 65= 286.00= 839.33= 53636.80
= 66= 281.59= 843.74= 52793.00
= 67= 277.16= 848.17= 51944.90
= 68= 272.71= 852.62= 51092.20
= 69= 268.24= 857.10= 50235.10
= 70= 263.74= 861.60= 49373.50
= 71= 259.21= 866.12= 48507.40
= 72= 254.66= 870.67= 47636.70
= 73= 250.09= 875.24= 46761.50
= 74= 245.50= 879.83= 45881.70
= 75= 240.88= 884.45= 44997.20
= 76= 236.24= 889.10= 44108.10
= 77= 231.57= 893.76= 43214.30
= 78= 226.88= 898.46= 42315.90
= 79= 222.16= 903.17= 41412.70
= 80= 217.42= 907.91= 40504.80
= 81= 212.65= 912.68= 39592.10
= 82= 207.86= 917.47= 38674.60
= 83= 203.04= 922.29= 37752.30
= 84= 198.20= 927.13= 36825.20
= 85= 193.33= 932.00= 35893.20
= 86= 188.44= 936.89= 34956.30
= 87= 183.52= 941.81= 34014.50
= 88= 178.58= 946.76= 33067.70
= 89= 173.61= 951.73= 32116.00
= 90= 168.61= 956.72= 31159.30
= 91= 163.59= 961.75= 30197.50
= 92= 158.54= 966.79= 29230.70
= 93= 153.46= 971.87= 28258.90
= 94= 148.36= 976.97= 27281.90
= 95= 143.23= 982.10= 26299.80
= 96= 138.07= 987.26= 25312.50
= 97= 132.89= 992.44= 24320.10
= 98= 127.68= 997.65= 23322.40
= 99= 122.44= 1002.89= 22319.60
= 100= 117.18= 1008.15= 21311.40
= 101= 111.89= 1013.45= 20297.90
= 102= 106.57= 1018.77= 19279.20
= 103= 101.22= 1024.12= 18255.10
= 104= 95.84= 1029.49= 17225.60
= 105= 90.44= 1034.90= 16190.70
= 106= 85.00= 1040.33= 15150.30
= 107= 79.54= 1045.79= 14104.50
= 108= 74.05= 1051.28= 13053.30
= 109= 68.53= 1056.80= 11996.50
= 110= 62.98= 1062.35= 10934.10
= 111= 57.41= 1067.93= 9866.18
= 112= 51.80= 1073.53= 8792.64
= 113= 46.16= 1079.17= 7713.47
= 114= 40.50= 1084.84= 6628.64
= 115= 34.80= 1090.53= 5538.11
= 116= 29.08= 1096.26= 4441.85
= 117= 23.32= 1102.01= 3339.84
= 118= 17.54= 1107.80= 2232.04
= 119= 11.72= 1113.61= 1118.43
= 120= 5.87= 1119.46=- 1.03

= 0.00TOTAL INTEREST= 35039.0

PRINCIPAL: :

Pito
Fri Nov 04, 2016 10:44 pm
I’ve tried with CHESS from DEC tape, converted binary into chess.h, but it halts with:
LOAD 0000-6376 CHECK 7567

CHEKMO-II
W. YOUR MOVE?
HALT 0000

ahull
Sat Nov 05, 2016 12:07 am
I’ll need to give this a shot when I get a moment.

Image

Its interesting to think that I can now get a $2 board to emulate a DEC machine which when introduced on March 22, 1965 was priced at $18,500 (equivalent to about $140,000 in 2015). Furthermore the $2 board consumes about a millionth of the power and occupies about a millionth of the space. :D

I wonder how easy it would be to emulate a Datageneral Nova.

http://www.simulogics.com/

Image

zmemw16
Mon Nov 07, 2016 11:13 am
and how many of us used or even remember the switch setting & toggling at start up?
+1 +0
stephen
evildave_666
Mon Nov 07, 2016 11:34 am
zmemw16 wrote:and how many of us used or even remember the switch setting & toggling at start up?
+1 +0
stephen
Ollie
Mon Nov 07, 2016 6:22 pm
It was tens of times that I had to “toggle” a PDP15 to be able to read the boot loader from a paper tape. The PDP15 was a wonderful machine with graphic subroutines. The display was fully vector based, including all the text shown on the screen. Oh boy, those were the good old days.

Cheers, Ollie

Pito
Tue Nov 08, 2016 1:00 am
Today I flashed the OpenCore’s PDP-8 design into a small Spartan6 board.
Board+SdCard+Console and it works, somehow..
As I can read here a lot of people actually worked with the stuff, so if you may advice me what is going wrong with my box I would appreciate..
http://retrobsd.org/viewtopic.php?f=3&t … 038#p44038
ahull
Tue Nov 08, 2016 3:40 pm
This reminds me of a visit to the DEC plant in Ayr (Scotland), many years ago. One of my school friends mother worked there, and the pair of aspiring geeks managed to persuade her to let us see round the factory. As I recall, they were building the DEC Mate and the DEC Rainbow (and a few other things). Lots of PCBs everywhere… quite an interesting time. Many years later I visited the same factory to repair a large line printer (Genicom I think).
At that point I think they were producing the DEC Alpha platform.

Digital Equipment Corporation (Scotland) Ltd., Mosshill Industrial Estate, Ayr, Scotland. KA6 6BE.

The plant now appears to produce cook ware and kitchens. :roll: So much for the high tech boom of the 1980 and 90s.

zmemw16
Tue Nov 08, 2016 3:57 pm
flying saucer hard case disks, just about needed 2 hands, yonks to spin up or down
don’t start me on Coral-66 compiler, finds an error and dumps file source remaining on end of the object file.
took me a while for that one.
stephen

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