shirriff

// Loads a PRU text.bin (and optionally data.bin) file,
// executes it, and waits for completion.
//
// Usage:
// $ ./loader text.bin [data.bin]
//
// Compile with:
// gcc -o loader loader.c -lprussdrv
//
// Based on https://credentiality2.blogspot.com/2015/09/beaglebone-pru-gpio-example.html

shirriff

# Crack Xerox Alto disk passwords using math.

import sys

def findPasswd(passvec):
  # a and b are the salt values
  a = (passvec[1] << 16) + passvec[2]
  b = (passvec[3] << 16) + passvec[4]
  if a == 0 or b == 0:
    print 'No password'

shirriff

               job  prime1.s
     * Compute primes 2-255 for toggle challenge
     * Ken Shirriff  http://righto.com
               ctl  6641
     
               org  201             * Start of print buffer
     num       dcw  002             * Current number

               org  333             * Start of code memory
     outer     mcw  @002@, factor   * Start with factor 2

shirriff

               job  card.s
               ctl  6641
               org  087
     X1        dcw  000  * Index 1, pointer to text
               dc   00
               org  333
     start     sw   1
               sbr  x1, buf+80
     rloop     r                   * Read cards into page buffer
               bce  rhs, 1, -

shirriff

# Process font file to generate FPGA code

# Font from https://github.com/dhepper/font8x8/blob/master/font8x8_basic.h

import re

chars = []
for line in open('font8x8_basic.h').readlines():
  m = re.search('{([\s0-9A-Fa-fx,]*)}', line)
  if m:

shirriff

# Process font file to generate FPGA code

# Font from https://github.com/dhepper/font8x8/blob/master/font8x8_basic.h

import re

chars = []
for line in open('font8x8_basic.h').readlines():
  m = re.search('{([\s0-9A-Fa-fx,]*)}', line)
  if m:

shirriff

# Disable password protection on an Alto disk by zeroing out the password flag in sys.boot

import sys
import subprocess

diskContents = None

# Get word at the word offset in the disk file
def getWord(wordOffset):
  return ord(diskContents[2 * wordOffset]) + ord(diskContents[2 * wordOffset + 1]) * 256

shirriff

for (bit_count = 0; bit_count < 8; bit_count++) {
    if (byte & 0x80) {
        wait_for_pwm_timer();
        __R30 = HIGH << WRITE_PIN;
        wait_for_pwm_timer();
        __R30 = LOW << WRITE_PIN;
    } else {
        wait_for_pwm_timer();
        __R30 = LOW << WRITE_PIN;
        wait_for_pwm_timer();

shirriff

import re

data="""\
10100001 10010011 01100011  => 01110111
  10100001 10010011 01100100  => 01110001
  10100001 10010011 01100101  => 01110000
  10100001 10010011 01100110  => 01110010
  10100001 10010011 01100111  => 01110011
  10100001 10010011 01101000  => 01111001
  10100001 10010011 01101001  => 01111000

shirriff

import re

# Each line is 3 bytes of input and the observed 1-byte checksum
data="""\
10100001 10010011 01100011  => 01110111
10100001 10010011 01100100  => 01110001
10100001 10010011 01100101  => 01110000
10100001 10010011 01100110  => 01110010
10100001 10010011 01100111  => 01110011
10100001 10010011 01101000  => 01111001