1. LING 408/508: Programming for Linguists Lecture 1 August 24 th

2. Administrivia 1.Syllabus 2.Introduction 3.Quickie Homework 1 – due Wednesday night by midnight in my e-mailbox I will assume everyone has a laptop…

3. Syllabus Details – Instructor: Sandiway Fong Depts. Linguistics and Computer Science – Email: sandiway@email.arizona.edu (homeworks go here)sandiway@email.arizona.edu – Office: Douglass 311 – Hours: by appt. or walk-in, after class – Meet: Shantz 338, Mondays/Wednesdays 3:15-4:30pm – No class on: Monday September 7th (Labor Day) Wednesday November 11 th (Veterans Day) Week after September 11 th (out of town), plus Monday 21 st Monday October 12 th – My academic webpage: dingo.sbs.arizona.edu/~sandiway/ or just Google me

4. Syllabus dingo.sbs.arizona.edu/~sandiway/ – Lecture slides will be available online (.pptx and pdf formats) just before class look for updates/corrections afterwards – Lectures will be recorded using the panopto system (video, laptop screen, synchronized slides, keyword search)

5. Syllabus Pre-requisites: – none! Course Objectives: – Introduction to programming data types, different programming styles, thinking algorithmically … – and fundamental computer concepts computer organization: underlying hardware, and operating systems (processes, shell, filesystem etc.) – Operating System: Ubuntu (Linux) – Programming Languages: selected examples: Bash shell, Python, Javascript, Perl, Tcl/Tk, HTML/CSS, MySQL, cgi-bin etc.

6. Syllabus Expected learning outcomes: – familiarity with the underlying technology, terminology and programming concepts – acquire the ability to think algorithmically – acquire the ability to write short programs – build a graphical user interface – build a web application (with a relational database) – be equipped to take classes in the Human Language Technology (HLT) program and related classes

7. Syllabus Grading – 408: homeworks (80%), term programming project (20%) – 508: homeworks (65%), term programming project (35%) – Note: requirement – you must submit all homeworks Homework submissions: – email only to me – See homework 1 for the required format … – homeworks will be introduced in class – due date: almost one week (typically) example: homework presented in class on Monday (resp. Wednesday), due Sunday (resp. Tuesday) night by 11:59pm in my mailbox – all homeworks will be reviewed in class

8. Syllabus Homeworks – you may discuss questions with other students – however, you must program/write it up yourself (in your own words/code) – cite (web) references and your classmates (in the case of discussion) – Student Code of Academic Integrity: plagiarism etc. http://deanofstudents.arizona.edu/codeofacademicintegrity Revisions to the syllabus – “the information contained in the course syllabus, other than the grade and absence policies, may be subject to change with reasonable advance notice, as deemed appropriate by the instructor.”

9. Syllabus Absences – tell me ahead of time so we can make special arrangements, e.g. homeworks – I expect you to attend lectures (though attendance will not be taken)

10. Introduction Computers – Memory Programs and data – CPU Interprets machine instructions – I/O keyboard, mouse, touchpad, screen, touch sensitive screen, printer, usb port, etc. bluetooth, ethernet, wifi, cellular …

11. Introduction Memory – CPU registers – L1/L2 cache – RAM – SSD/hard drive – blu ray/dvd/cd drive fast slow invisible to programmers open file read/write

12. Introduction Memory Representation – binary: zeros and ones (1 bit) – organized into bytes (8 bits) memory is byte-addressable – word (32 bits) e.g. integer (64 bits: floating point number) – big-endian/little-endian most significant byte first or least significant byte communication … addressable Memory (RAM) addressable Memory (RAM) 0 FFFFFFFF your Intel and ARM CPUs array a[23]

13. Introduction A typical notebook computer – Example: a 2013 Macbook Air – CPU: Core i5-4250U 1.3 billion transistors built-in GPU TDP: 15W (1.3 GHz) Dual core (Turbo: 2.6 GHz) Hyper-Threaded (4 logical CPUs, 2 physical) 64 bit 64 KB (32 KB Instruction + 32 KB Data) L1 cache 256 KB L2 cache per core 12MB L3 cache shared 16GB max RAM Increased address space and 64-bit registers

14. Introduction anandtech.com A 4 core machine: 8 virtual

15. Introduction Machine Language – A CPU understands only one language: machine language all other languages must be translated into machine language – Primitive instructions include: MOV PUSH POP ADD / SUB INC / DEC IMUL / IDIV AND / OR / XOR / NOT NEG SHL / SHR JMP CMP JE / JNE / JZ / JG / JGE / JL / JLE CALL / RET Assembly Language: (this notation) by definition, nothing built on it is more powerful http://www.cs.virginia.edu/~evans/cs216/guides/x86.html

16. Introduction Not all the machine instructions are conceptually necessary – many provided for speed/efficiency Theoretical Computer Science – All mechanical computation can be carried out using a TURING MACHINE – Finite state table + (infinite) tape – Tape instructions: at the tape head: Erase, Write, Move (Left/Right/NoMove) – Finite state table: Current state x Tape symbol --> new state x New Tape symbol x Move

17. Introduction Storage: – based on digital logic – binary (base 2) – everything is a power of 2 – Byte: 8 bits 01011011 = 2 6 +2 4 +2 3 +2 1 +2 0 = 64 + 16 + 8 + 2 + 1 = 91 (in decimal) – Hexadecimal (base 16) 0-9,A,B,C,D,E,F (need 4 bits) 5B (= 1 byte) = 5*16 1 + 11 = 80 + 11 = 91 2727 2626 2525 2424 23232 2121 2020 2727 2626 2525 2424 23232 2121 2020 01011011 23232 2121 2020 23232 2121 2020 5 B 23232 2121 2020 23232 2121 2020 0101 23232 2121 2020 23232 2121 2020 01011011 16 1 16 0 16 1 16 0 5B

18. Introduction: data types Integers – In one byte (= 8 bits), what’s the largest and smallest number, we can represent? – 00000000 = 0 – 01111111 = 127 – 10000000 = -128 – 11111111 = -1 0…127-128-127 0000000011111111 2’s complement representation

19. Introduction: data types Integers – In one byte, what’s the largest and smallest number, we can represent? – Answer: -128.. 0.. 127 using the 2’s complement representation – Why? super-convenient for arithmetic operations – “to convert a positive integer X to its negative counterpart, flip all the bits, and add 1” – Example: – 00001010 = 2 3 + 2 1 = 10 (decimal) – 11110101 + 1 = 11110110 = -10 (decimal) – 11110110 flip + 1 = 00001001 + 1 = 00001010 Addition: -10 + 10 = 11110110 + 00001010 = 0 (ignore overflow)

20. Introduction: data types Typically 32 bits (4 bytes) are used to store an integer – range: -2,147,483,648 (2 (31-1) -1) to 2,147,483,647 (2 (32-1) -1) what if you want to store even larger numbers? – Binary Coded Decimal (BCD) – code each decimal digit separately, use a string (sequence) of decimal digits … 2 31 2 30 2 29 2 28 2 27 2 26 2 25 2 24 ……2727 2626 2525 2424 23232 2121 2020 byte 3byte 2byte 1byte 0 C: int

21. Introduction: data types what if you want to store even larger numbers? – Binary Coded Decimal (BCD) – 1 byte can code two digits (0-9 requires 4 bits) – 1 nibble (4 bits) codes the sign (+/-), e.g. hex C/D 23232 2121 2020 0000 23232 2121 2020 0001 23232 2121 2020 1001 0 1 9 2014 2 bytes (= 4 nibbles) +2014 2.5 bytes (= 5 nibbles) 23232 2121 2020 1100 C 23232 2121 2020 1101 D credit (+) debit (-)