Money Analyzer 2

Money Analyzer 2 is a multi-module financial analysis suite covering three related engineering-economics calculations: asset depreciation, present worth comparison of investment alternatives, and rate of return estimation. The depreciation module implements three standard methods — straight-line, sum-of-years-digits, and declining balance — displaying a year-by-year table of depreciation charges and remaining book value. The present worth module finds a common life multiple (up to 20 iterations) across alternatives with differing expected lives before computing net present worth for each. The rate of return module uses a three-pass bisection-style search, stepping through interest rates at decreasing granularity (0.05, 0.01, then 0.001) to converge on a solution to two decimal places, switching to FAST mode during computation and back to SLOW for display.

Program Analysis

Money Analyzer 2 is structured as three largely independent BASIC programs sharing a common financial theme. Each begins near or at line 100 and manages its own input/output flow. The depreciation section uses low-numbered subroutines (lines 10–39) dispatched via a computed GOSUB X*10, while the present worth and rate of return sections are self-contained sequential programs. The listing appears to represent the programs concatenated for publication rather than a single unified program.

Module 1: Depreciation

The main loop at lines 100–300 collects the asset’s initial value (P), salvage value (S), and expected life in years (N), then presents a menu of four options. The dispatcher at line 290 uses the elegant idiom GOSUB X*10 to branch to the appropriate subroutine based on the user’s numeric choice, routing to line 10, 20, or 30 for the three depreciation methods.

• Straight-line (lines 10–16): Computes a fixed annual charge D = INT((P-S)/N + 0.5) and accumulates the book value by subtraction each year.
• Sum-of-years-digits (lines 20–28): Calculates the SYD denominator as N*(N+1)/2, then weights each year’s charge by the remaining life fraction (N-I+A)/SYD, where A is used as the constant 1.
• Declining balance (lines 30–39): Prompts for a depreciation rate R, computes each year’s charge as INT(R*P*((A-R)**(I-A)) + 0.5), and includes a floor guard at line 34 to prevent book value dropping below salvage: IF V-D<S THEN LET D=V-S.

Variable names A, B, C, E are used as numeric constants throughout (likely set before the listing begins via LET A=1, LET B=3, etc., acting as column and row offsets for PRINT AT and TAB). SCROLL is used before each row of output to keep the table scrolling without a “scroll?” prompt. After displaying the full schedule, PAUSE 40000 holds the screen before returning to the method menu.

Module 2: Present Worth Comparison

This module collects data for up to six attributes of up to N investment alternatives into a two-dimensional array D(6,N) (line 140). The fields stored per alternative are first cost, yearly cost, salvage value, and expected life. A common analysis period C is found by searching integer multiples of the longest alternative life L until all life spans divide evenly (lines 310–380).

The present worth formula at line 490 deserves close reading:

• S accumulates the present worth of repeated replacement cycles (excluding the final cycle): (F-V)*(1/((1+A)**(I*E))) for I from 1 to Z = C/E - 1.
• The final expression combines this with first cost, terminal salvage, and the present worth of the uniform annual cost series: INT(S + F - V/L + Y*((L-1)/(A*L))), where L is reused here as the compound interest factor (1+A)**C (line 440), shadowing its earlier role as maximum life. This reuse is a potential source of confusion.

If no common multiple is found within 20 multiples, the program prints a “NO COMMON MULTIPLE FOUND” message (lines 376–378) and falls through to line 520, which does not appear in the listing — this is a dangling GOTO and would cause an error at runtime if triggered.

Module 3: Rate of Return

This module estimates the interest rate at which an investment breaks even, using a three-pass successive-approximation approach rather than a closed-form solution. The core inequality tested in subroutine line 60 is:

P + Y1*PWUA(I,N) >= Y2*PWUA(I,N) + F*PW(I,N)

where PWUA is the present-worth uniform-annuity factor ((1+I)**N - 1)/(I*(1+I)**N) and PW is the present-worth factor 1/(1+I)**N. When the inequality is first satisfied the current I is saved to G via line 50, and GOTO T exits the subroutine back to the appropriate outer loop — T is set to 400, 500, or 600 depending on the current pass (lines 305, 405, 505).

The IF I=0 THEN GOTO guard on lines 310, 410, and 510 skips the subroutine when I is exactly zero to avoid division by zero in the annuity formula. After convergence, line 603 rounds to four decimal places and line 603 converts to a percentage: (INT(I*10000+0.5))/100. FAST mode is engaged at line 230 for the iterative computation and SLOW is restored at line 605 before printing the result.

Notable Techniques and Anomalies

• The computed GOSUB X*10 dispatch (line 290) is an efficient and readable alternative to a chain of IF statements.
• Single-letter constants (A, B, C, E) for screen layout coordinates reduce repetition but depend on initialization code not present in this listing.
• In the present worth module, variable L is repurposed between lines 275 (maximum life) and 440 (compound factor), making the formula at line 490 ambiguous without careful reading of execution order.
• The GOTO 520 at line 378 targets a line that does not exist in the listing, which would generate an error if no common multiple is found.
• In the rate of return module, GOTO T uses a variable as the branch target, an efficient idiom for multi-exit subroutine control flow.
• Rounding of depreciation and present worth figures throughout uses the standard INT(x + 0.5) idiom for nearest-integer rounding.

  10 LET D=INT (((P-S)/N)+.5)
  11 FOR I=A TO N
  12 LET V=INT (P-I*D)
  13 SCROLL
  14 PRINT " ";I;TAB C;"$";D;TAB E;"$";V
  15 NEXT I
  16 RETURN
  20 LET SYD=(N*(N+1))/2
  22 FOR I=A TO N
  23 LET D=INT ((((N-I+A)*(P-S))/SYD)+.5)
  24 LET V=V-D
  25 SCROLL
  26 PRINT " ";I;TAB C;"$";D;TAB E;"$";V
  27 NEXT I
  28 RETURN
  30 PRINT AT A,C;" INPUT RATE" 
  31 INPUT R
  32 FOR I=A TO N
  33 LET D=INT ((R*P*((A-R)**(I-A)))+.5)
  34 IF V-D<S THEN LET D=V-S
  35 LET V=V-D
  36 SCROLL
  37 PRINT " ";I;TAB C;"$";D;TAB E;"$";V
  38 NEXT I
  39 RETURN
  90 SAVE "DEPRECIATIO[N]"
 100 PRINT AT 0,C;"DEPRECIATION";AT A,C;"▀▀▀▀▀▀▀▀▀▀▀▀"
 120 PRINT AT B,B;" INPUT INITIAL VALUE"
 130 INPUT P
 140 PRINT AT B,B;" INPUT SALVAGE VALUE"
 150 INPUT S
 160 PRINT AT B,B;" INPUT EXPECTED LIFE"
 170 INPUT N
 200 CLS
 210 PRINT AT B,2;"SELECT DEPRECIATION METHOD:"
 220 PRINT AT 7,2;"CODE  METHOD"
 230 PRINT AT C,B;"1   STRAIGHT LINE"
 240 PRINT AT 10,B;"2   SUM OF YEARS DIGITS"
 250 PRINT AT 11,B;"3   DECLINING BALANCE"
 260 PRINT AT 12,B;"4   NEW DATA"
 270 INPUT X
 280 IF X<A OR X>B THEN GOTO 210
 284 CLS
 285 IF X=4 THEN GOTO 100
 286 PRINT AT 20,0;"YEAR   DEPRECIATION   BOOK VALUE"
 287 PRINT " 0";TAB 12;"-";TAB E;"$";P
 289 LET V=P
 290 GOSUB X*10
 291 PAUSE 40000
 300 GOTO 200
 
 
 100 PRINT AT 1,3;"PRESENT WORTH COMPARISON"
 110 PRINT AT 2,3;"▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀"
 120 PRINT AT 5,1;" INPUT NUMBER OF ALTERNATIVES"
 125 LET L=0
 130 INPUT N
 140 DIM D(6,N)
 150 PRINT AT 5,1;" INPUT DATA FOR ALTERNATE  ";
 160 FOR X=1 TO N
 170 PRINT AT 5,28;X
 180 PRINT AT 7,7;" FIRST COST?    "
 190 INPUT D(1,X)
 220 PRINT AT 7,6;"   YEARLY COST?"
 230 INPUT D(2,X)
 240 PRINT AT 7,3;"    SALVAGE VALUE?      "      
 250 INPUT D(3,X)
 260 PRINT AT 7,7;"EXPECTED LIFE?"
 270 INPUT D(4,X)
 275 IF L<D(4,X) THEN LET L=D(4,X)
 280 NEXT X
 290 PRINT AT 7,7;"INTEREST RATE"
 300 INPUT A
 310 FOR X=1 TO 20
 320 LET S=0
 330 LET C=L*X
 340 FOR I=1 TO N
 350 IF INT (C/D(4,I))-C/D(4,I)<0 THEN GOTO 380
 360 LET S=S+1
 370 NEXT I
 375 IF S=N THEN GOTO 381
 376 CLS
 377 PRINT "  NO COMMON MULTIPLE FOUND";AT 1,8;" FOR YEARS"
 378 GOTO 520
 380 NEXT X
 381 CLS
 382 PRINT TAB 5;"ALT";TAB 15;"PRESENT WORTH"
 390 FOR X=1 TO N
 400 LET F=D(1,X)
 410 LET Y=D(2,X)
 420 LET V=D(3,X)
 430 LET E=D(4,X)
 440 LET L=(1+A)**C
 450 LET Z=(C/E)-1
 455 LET S=0
 460 FOR I=1 TO Z
 470 LET S=S+(F-V)*(1/((1+A)**(I*E)))
 480 NEXT I
 490 LET D(6,X)=INT (S+F-V/L+Y*((L-1)/(A*L)))
 500 PRINT AT 3+X,6;X;TAB 18;"$";D(6,X)
 510 NEXT X
  10 GOTO 100
  50 LET G=I
  60 IF P+(Y1*((1+I)**N-1))/(I*(1+I)**N)>=Y2*((1+I)**N-1)/(I*(1+I)**N)+F/(1+I)**N THEN GOTO T
  70 RETURN
 100 PRINT AT 0,8;"RATE OF RETURN"
 110 PRINT AT 1,8;"▀▀▀▀▀▀▀▀▀▀▀▀▀▀"
 120 PRINT AT 5,1;"INPUTS:"
 125 PRINT AT 7,3;"INITIAL INVESTMENT?"
 130 INPUT P
 140 PRINT AT 7,21;"..$";P;AT 9,3;"YEARLY COST?"
 150 INPUT Y1
 160 PRINT AT 9,14;".........$";Y1;AT 11,3;"YEARLY RETURN?"
 170 INPUT Y2
 180 PRINT AT 11,16;".......$";Y2;AT 13,3;"FINAL VALUE?"
 190 INPUT F
 200 PRINT AT 13,14;".........$";F;AT 15,3;"INVESTMENT TERM?"
 210 INPUT N
 220 PRINT AT 15,18;".....";N;" YEARS"
 225 PAUSE 200
 230 FAST
 300 FOR I=0 TO 2 STEP .05
 305 LET T=400
 310 IF I=0 THEN GOTO 330
 320 GOSUB 50
 330 NEXT I
 400 FOR I=G-.05 TO G+.01 STEP .01
 405 LET T=500
 410 IF I=0 THEN GOTO 430
 420 GOSUB 50
 430 NEXT I
 500 FOR I=G-.01 TO G+.01 STEP .001
 505 LET T=600
 510 IF I=0 THEN GOTO 530
 520 GOSUB 50
 530 NEXT I
 600 IF I<=.001 THEN LET I=0
 603 LET I=(INT (I*10000+.5))/100
 605 SLOW
 610 PRINT AT 17,3;"RATE OF RETURN......";I;" P/C"