ix ;;Quote: brief history of the development of the EDSAC by Wilkes and others; 1946-1949

xiv ;;Quote: a Japanese computer, the TAC, used the same order codes and subroutine library as the EDSAC; only source was this book

xxi ;;Quote: the EDSAC subroutine library included the Runge-Kutta-Gill process for solving differential equations

xxii ;;Quote: Wilkes preferred print orders and post-mortem routines over "peeping", i.e., observing a program's progress through a CRT monitor

xxiv ;;Quote: scaling was the most difficult part of programming the EDSAC

xxv ;;Quote: the EDSAC book includes code for the principal library subroutines. It served as a model for early programmers

xxvi ;;Quote: can simulate the EDSAC and its subroutine library from the book

1 ;;Quote: a program is a sequence of orders for performing a calculation; unlike a human, every contingency must be foreseen

1+;;Quote: a computer can perform only the basic operations of arithmetic

1 ;;Quote: with a computer, the simplest mathematical calculation requires an extended sequence of orders

1+;;Quote: use subroutines to reduce the labor of writing a program; i.e., short, ready-made programs

1+;;Quote: it is worth-while to spend much effort on the establishment of a subroutine library and a system for combining subroutines into a program

3 ;;Quote: use the same memory for both orders and numbers by expressing orders in a numerical code; from von Neumann's report

3+;;Quote: a computer consists of memory, an arithmetical unit, input and output mechanisms, and a control unit

3 ;;Quote: the EDSAC used 1024 numbers of ultrasonic memory; 17 or 35 binary digits from -1 to 1

3+;;Quote: the address of x is the reference number of the storage location holding x

5 ;;Quote: EDSAC code used 18 orders indicated by letters with an address and length flag

9 ;;Quote: construct a program with many fewer orders by modifying the orders during program execution

15 ;;Quote: the EDSAC initial orders converted symbolic orders to binary form and loaded them into memory; reduces error; 41 words

17 ;;Quote: use "control combinations" to direct EDSAC's initial orders

19 ;;Quote: use relocatable code for library subroutines; allows mechanical copying of subroutines

22 ;;Quote: an open subroutine is copied as is to a program; a closed subroutine is called from the master routine with a Wheeler jump

23 ;;Quote: a preset parameter is evaluated at load time; a program parameter is placed immediately after the subroutine call

25 ;;Quote: for each subroutine, EDSAC's library catalog gave a concise specification, operating time, storage space, and the orders in full

27 ;;Quote: the assembly subroutine combined a master routine with subroutines, generated subroutine calls, and resolved input data; seldom used

34 ;;Quote: EDSAC include interpretive routines for complex numbers and floating point arithmetic; they coined the term

35 ;;Quote: an interpretive routine extends the order code of the machine at the cost of greater execution time

38 ;;Quote: it is easy to make expensive programming errors; the EDSAC group developed techniques to avoid or detect errors before execution and to locate errors after execution

38 ;;Quote: test subroutines with short programs constructed for the purpose

38 ;;Quote: avoid and detect errors by orderly and logical programs; rewrite if necessary and provide documentation

38+;;Quote: the EDSAC group did not use flowcharts

38 ;;Quote: use desk checking to verify that subroutines occupy distinct locations, specifications are satisfied, overwrites do not occur, and unpreserved registers are invalid

39 ;;Quote: use a post-mortem program to print the contents of store after an error or infinite loop

39 ;;Quote: trace program execution by printing a letter when each subroutine executes

40 ;;Quote: check a program by interpreting the program instead of executing it directly; print additional information

40 ;;Quote: a blocking order transfers control from a program to the checking routine

41 ;;Quote: debug a program by printing intermediate results; include extra printing with the first draft

41 ;;Quote: subroutines for the assembly of repetitive programs; like structured programming, but seldom used

42 ;;Quote: users punched their own tape and hanged the tape with a ticket on a horizontal wire; the operator processed the tapes in order

43 ;;Quote: punch input data, master routine, and subroutines separately; each tape punched twice and compared to catch errors

166 ;;Quote: reduce the number of orders by using tags instead of counting; e.g., use -1 to end a sequence of positive numbers

167 ;;Quote: use a multiway switch to select a route with a number