RosettaCodeData/Task/Pangram-checker/EDSAC-order-code/pangram-checker.edsac
2020-02-17 23:21:07 -08:00

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5.3 KiB
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[Pangram checker for Rosetta Code.
EDSAC program, Initial Orders 2.]
[Outline: Make a table, one entry per 5-bit character code.
Initialize entry for each letter to 1.
When a letter is read, convert its entry to 0.]
[Subroutine to read string from the input and
store it with character codes in low 5 bits.
String is terminated by blank row of tape, which is stored.
Input: 0F holds address of string in address field (bits 1..11).
21 locations; workspace: 4F]
T 56 K
GKA3FT17@AFA18@T7@I4FA4FUFS19@G12@S20@G16@T4FA7@A2FE4@T4FEFUFP8FPD
[*************** Rosetta Code task ***************
Subroutine to test whether string is a pangram.
Input: 0F = address of string, characters in low 5 bits,
terminated by blank row of tape.
Output: 1F = (number of missing letters) - 1.
87 memory locations; workspace 4F.]
T 88 K
G K
A 3 F [make and plant link for return]
T 48 @
[Fill letter table with 1's.
The code is a bit neater if we work backwards.]
A 54 @ [index of last entry]
[3] A 51 @ [make T order for table entry]
T 6 @ [plant in code]
A 53 @ [acc := 1]
[6] T F [table entry := 1]
A 6 @ [dec address in table]
S 2 F
S 51 @ [finished table?]
E 3 @ [loop back if not]
[Set non-letters to 0, except blank row := -1]
T 4 F [clear acc]
T 66 @ [figures shift]
T 70 @ [letters shift]
T 73 @ [carriage return]
T 75 @ [space]
T 79 @ [line feed]
S 53 @ [acc := -1]
T 71 @ [blank row of tape]
[Loop to read characters from string.
Terminated by blank row of tape.
Assume acc = 0 here.]
A F [load address of string]
A 49 @ [make order to read first char]
[21] T 22 @ [plant in code]
[22] A F [char to acc]
L D [shift to address field]
A 50 @ [make A order for this char in table]
U 28 @ [plant in code]
A 52 @ [convert to T order]
T 31 @ [plant in code]
[28] A F [load table entry]
G 35 @ [jump out if it's -1, i.e. blank row]
T 4 F [clear acc]
[31] T F [table entry := 0 to flag that letter is present]
A 22 @ [inc address in input string]
A 2 F
G 21 @ [back to read next char]
[Get total of table entries, again working backwards.
The number of missing letters is (total + 1).]
[35] T 4 F [clear acc]
T 1 F [initialize total := 0]
A 54 @ [index of last entry]
[38] A 50 @ [make A order for table entry]
T 41 @ [plant in code]
A 1 F [load total so far]
[41] A F [add table entry]
T 1 F [update total]
A 41 @ [load A order]
S 2 F [dec address]
S 50 @ [finished table?]
E 38 @ [loop back if not]
T 4 F [clear acc before exit]
[48] E F
[Constants]
[49] A F [to make A order referring to input]
[50] A 55 @ [to make A order referring to table]
[51] T 55 @ [to make T order referring to table]
[52] O F [add to A order to convert to T order]
[53] P D [constant 1]
[54] P 31 F [to change address by 31]
[Table]
[55] PFPFPFPFPFPFPFPFPFPFPF
[66] PFPFPFPF [11 = figures shift]
[70] PF [15 = letters shift]
[71] PFPF [16 = blank row of tape]
[73] PFPF [18 = carriage return]
[75] PFPFPFPF [20 = space]
[79] PFPFPFPFPFPFPFPF [24 = line feed]
[Main routine to demonstrate pangram-checking subroutine]
T 200 K
G K
[Constants]
[0] P 25 @ [address for input string]
[1] N F [letter N]
[2] Y F [letter Y]
[3] K 2048 F [letter shift]
[4] @ F [carriage return]
[5] & F [line feed]
[6] K 4096 F [null char]
[Enter with acc = 0]
[7] O 3 @ [set letters shift]
[8] A @ [load address of input]
T F [pass to input subroutine in 0F]
[10] A 10 @ [call input subroutine, doesn't change 0F]
G 56 F
[12] A 12 @ [call pangram subroutine]
G 88 F
[We could print the number of missing letters,
but we'll just print 'Y' or 'N'.]
A 1 F [load (number missing) - 1]
E 18 @ [jump if not pangram]
O 2 @ [print 'Y']
G 19 @ [exit]
[18] O 1 @ [print 'N']
[19] O 4 @ [print CR, LF]
O 5 @
O 6 @ [print null to flush printer buffer]
Z F [stop]
T F [on Reset, clear acc]
E 8 @ [and test another string]
[25] [input string goes here]
E 7 Z [define entry point]
P F [acc = 0 on entry]
THE!QUICK!BROWN!FOX!JUMPS!OVER!THE!LAZY!DOG.