---
title: "Ad Profit"
id: 56991
type: "computer_media"
slug: "ad-profit"
url: "http://localhost/computer_media/ad-profit/"
markdown_url: "http://localhost/computer_media/ad-profit.md"
published_at: "2024-10-02T01:22:17+00:00"
modified_at: "2026-03-30T21:20:25+00:00"
author: "David Anderson"
featured_image:
  url: "http://localhost/wp-content/uploads/2024/10/16_AdPro.png"
excerpt: "Enter your retail price, wholesale cost, ad spend, and units sold to instantly calculate campaign profit — or find your break-even point automatically."
category:
  - name: "Archived Media"
    slug: "archived-media"
    taxonomy: "category"
    url: "http://localhost/category/archived-media/"
post_tag:
  - name: "Downloadable"
    slug: "downloadable"
    taxonomy: "post_tag"
    url: "http://localhost/tag/downloadable/"
  - name: "TS 1000"
    slug: "ts1000"
    taxonomy: "post_tag"
    url: "http://localhost/tag/ts1000/"
model:
  - name: "Timex/Sinclair 1000"
    slug: "ts-1000"
    taxonomy: "model"
    url: "http://localhost/model/ts-1000/"
genre:
  - name: "Business"
    slug: "business"
    taxonomy: "genre"
    url: "http://localhost/type/business/"
media_contents:
  - id: 56732
    title: "Timex Sinclair Public Domain Library Tape 1001"
    type: "computer_media"
    url: "http://localhost/computer_media/timex-sinclair-public-domain-library-tape-1001/"
media_type: "Program"
mediadate: "198x"
images:
  - url: "http://localhost/wp-content/uploads/2024/10/16_AdPro.png"
media_type_tags: "Business"
---

# Ad Profit

This program calculates advertising campaign profit, taking inputs for retail price, wholesale cost, advertising expenditure, and quantity sold. It then computes net profit using the formula E = A×B − A×C − D. A break-even mode is triggered when the user enters 0 for quantity sold, whereupon the program instead solves for the number of units required to achieve a desired profit target using the rearranged formula A = (F+D)/(B−C). The program loops continuously, clearing the screen and restarting the input sequence after each calculation.

***

## Program Analysis

### Program Structure

The program is divided into clearly delineated functional blocks:

1. Lines 1–4: Title display and instructions
2. Lines 10–120: Input collection (retail price, wholesale cost, ad cost, quantity sold)
3. Line 130: Branch decision — normal profit vs. break-even mode
4. Lines 200–220: Normal profit calculation and display
5. Lines 300–350: Break-even unit calculation
6. Lines 400–450: Loop control — wait for keypress, clear screen, restart
7. Lines 475–600: Save and auto-run block (never reached in normal execution)

### Key Variables

| Variable | Meaning |
| --- | --- |
| `B` | Retail (list) price per unit |
| `C` | Manufacturing or wholesale cost per unit |
| `D` | Total advertising cost |
| `A` | Quantity sold (or computed break-even quantity) |
| `E` | Calculated profit |
| `F` | Desired profit (break-even mode input) |

### Profit Calculation

In normal mode (line 200), profit is computed as `E = A*B - A*C - D`, which represents total revenue minus total cost-of-goods minus fixed advertising spend. This could be simplified to `E = A*(B-C) - D`, but the expanded form is functionally correct.

In break-even mode (line 330), the formula is algebraically rearranged to `A = (F+D)/(B-C)`, solving for the number of units needed. Entering 0 for profit wanted (`F=0`) gives the true break-even unit count.

### Key BASIC Idioms

- The keypress-wait loop at line 430 uses `IF INKEY$="" THEN GOTO 430`, a standard polling idiom on this platform.
- Each `INPUT` statement is preceded by a `PRINT` prompt and followed by an echoing `PRINT` of the entered value, giving a clean audit trail on screen.
- The infinite main loop is driven by `GOTO 10` at line 450 after a `CLS`, recycling the program without restarting it.

### Notable Anomalies

- Lines 475 (`CLEAR`), 500 (`SAVE`), and 600 (`RUN`) are unreachable during normal execution; the loop at line 450 never falls through to them. They exist solely as a tape-saving convenience to be run manually.
- No input validation is performed: entering identical values for `B` and `C` (i.e., zero margin) in break-even mode causes a division-by-zero error at line 330.
- The `PRINT A` echo at line 120 prints the raw numeric value of the quantity entered rather than formatting it with a label, which is inconsistent with the labelled echoes used for `B`, `C`, and `D`.

## Source Code

```
   1 REM AD PROFIT
   2 PRINT "%A%D% %C%A%M%P%A%I%G%N% %P%R%O%F%I%T"
   3 PRINT "ANSWER QUESTIONS AS REQUESTED.  IF YOU WISH TO KNOW HOW MANY UNITS TO SELL TO BREAK EVEN,ANSWER 0 TO NUMBER SOLD AND $ PROFIT WANTED"
   4 PRINT 
  10 PRINT "ITEM LIST/RETAIL PRICE: ";
  20 INPUT B
  30 PRINT "$";B
  40 PRINT "MFG OR WHOLESALE COST: ";
  50 INPUT C
  60 PRINT "$";C
  70 PRINT "AD COST: ";
  80 INPUT D
  90 PRINT "$";D
 100 PRINT "QUANTITY SOLD: ";
 110 INPUT A
 120 PRINT A
 130 IF A=0 THEN GOTO 300
 200 LET E=A*B-A*C-D
 210 PRINT "$";E;" PROFIT"
 220 GOTO 400
 300 PRINT "PROFIT WANTED: $ ";
 310 INPUT F
 320 PRINT F
 330 LET A=(F+D)/(B-C)
 340 PRINT "YOU MUST SELL  ";A
 350 PRINT "FOR $ ";F;" PROFIT"
 400 PRINT 
 410 PRINT 
 420 PRINT "FOR MORE,PRESS ANY KEY"
 430 IF INKEY$="" THEN GOTO 430
 440 CLS 
 450 GOTO 10
 475 CLEAR 
 500 SAVE "1001%6"
 600 RUN
```