Free tool · TAOCP §1.3

MIX emulator and MIXAL assembler, in your browser

Write MIXAL, assemble it and run it on MIX, the imaginary computer from Knuth's The Art of Computer Programming, right here. No install. 14 exercises from §1.3 are graded on the server when you submit them, and a pass verifies that week of the path.

       ORIG 100
START  ENTA 0
       ENT1 10
LOOP   INCA 0,1
       DEC1 1
       J1P  LOOP
       HLT
       END  START

Scratchpad

Graded exercises

Each one loads its starting code and test cases into the emulator. Check runs them in your browser; sign in to submit for credit.

• Hello, printer §1.3.2
  Print one fixed line on the line printer and halt. Verifies Knuth 1.3.2.
• Sum of a table §1.3.2
  Add up n signed numbers stored in memory. Verifies Knuth 1.3.2.
• Find the maximum §1.3.2 (Program M)
  A subroutine that returns the largest of n numbers and where it is. Verifies Knuth 1.3.2.
• Euclid's algorithm §1.1, §1.3.2
  Compute the greatest common divisor of two positive numbers. Verifies Knuth 1.3.2.
• Factorial §1.3.2
  Compute n! for small n. Verifies Knuth 1.3.2.
• Reverse a table in place §1.3.2
  Reverse the order of n words in memory without a second table. Verifies Knuth 1.3.2.
• Read a number from a card §1.3.1 (NUM)
  Convert ten decimal digits on a punched card to a binary number. Verifies Knuth 1.3.1.
• Print a number §1.3.1 (CHAR)
  Print the value in rA as ten decimal digits. Verifies Knuth 1.3.1.
• Copy cards to the printer §1.3.1 (I/O)
  Read k cards and print each one as a line. Verifies Knuth 1.3.1.
• Table of primes §1.3.2 (Program P)
  Compute the first 500 primes and print them as a 50-line table. Verifies Knuth 1.3.2.
• Saddle point §1.3.2
  Find an entry that is the smallest in its row and the largest in its column. Verifies Knuth 1.3.2.
• Date of Easter §1.3.2
  Print the date of Easter Sunday for a range of years. Verifies Knuth 1.3.2.
• Farey series §1.3.2
  A subroutine that generates the Farey series of order n with a two-term recurrence. Verifies Knuth 1.3.2.
• The Josephus problem §1.3.2
  Work out the order in which every m-th man in a circle of n is eliminated. Verifies Knuth 1.3.2.

Learn more: what MIX is, MIXAL, the §1.3.1 reading guide, how to read TAOCP and Volume 1.