---
title: "Degree of Conversion"
id: 57026
type: "computer_media"
slug: "degree-of-conversion"
url: "http://localhost/computer_media/degree-of-conversion/"
markdown_url: "http://localhost/computer_media/degree-of-conversion.md"
published_at: "2024-10-02T07:47:41+00:00"
modified_at: "2026-03-30T21:20:01+00:00"
author: "David Anderson"
featured_image:
  url: "http://localhost/wp-content/uploads/2024/10/50_Conv.png"
excerpt: "Enter a Fahrenheit range and step size, and this temperature converter prints a tidy three-column F/C/K table with randomly-generated block-graphic borders."
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: "Mathematics"
    slug: "mathematics"
    taxonomy: "genre"
    url: "http://localhost/type/mathematics/"
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/2024/10/50_Conv.png"
media_type_tags: "Mathematics"
---

# Degree of Conversion

This program converts temperatures from Fahrenheit to Celsius and Kelvin across a user-defined range and step size. The user inputs a low temperature, a high temperature, and a step interval; the program then prints a three-column table of F, C, and K values. A decorative border effect is produced by printing 32 (then 21) random block-graphic characters using CHR$(10*RND+128), which selects from the Spectrum/TS2068 block graphics in the range 128–137. The program handles reversed input order (high entered before low) by swapping A and B into E and F before the loop at line 300.

***

## Program Analysis

### Program Structure

The program is laid out in three broad phases:

1. **Title / decoration (lines 10–60):** Clears, prints a title, then draws a random block-graphic border of 32 characters.
2. **Input (lines 70–210):** Asks for the lowest Fahrenheit temperature, the highest, and the step size. Lines 160–190 reorder inputs so that `F` always holds the lower bound and `E` the upper, regardless of which the user entered first.
3. **Output (lines 220–360):** Clears the screen, prints a column header (F, C, K), draws a second random border of 21 characters, then loops from `F` to `E+Z` in steps of `Z`, computing and printing each row. On exit it saves and re-runs.

### Temperature Conversion

The Celsius conversion at line 310 uses the standard formula `C = 5*(D-32)/9`. Kelvin is derived at line 320 as `K = C+273`, using the common rounded value rather than the more precise 273.15. Results are printed with `TAB 8` for the Fahrenheit column and `TAB 24` for Kelvin; the comma separator after `C` advances to the next print zone, placing Kelvin approximately at column 24.

### Input Reordering Logic

Lines 160–190 implement a conditional swap without a dedicated temporary variable, using two separate flag-style assignments:

- Line 160: `IF B<A THEN LET E=A` — E gets the larger value when B is smaller
- Line 170: `IF A<B THEN LET F=A` — F gets the smaller value when A is smaller
- Line 180: `IF B<A THEN LET F=B` — F gets the smaller value when B is smaller
- Line 190: `IF A<B THEN LET E=B` — E gets the larger value when B is larger

This works correctly for the case where A ≠ B, but if `A = B` neither branch fires and `E` and `F` remain uninitialised, which would cause an error at line 300.

### Decorative Block Graphics

The border effect at lines 40–60 and 260–280 selects a random starting character with `H = 10*RND` (giving a value in [0,10)), adds 128, and prints that single CHR$ character in a loop. Since block graphic characters occupy codes 128–143, this lands within the block graphic set. However, using the same character repeated rather than cycling through them produces a uniform stripe rather than a varied pattern. A fresh random offset is chosen each time the program loops (via `RUN` at line 360), giving visual variety between runs.

### Variable Usage

| Variable | Purpose |
| --- | --- |
| `A` | First temperature entered by user |
| `B` | Second temperature entered by user |
| `E` | Upper bound of range (after reordering) |
| `F` | Lower bound of range (after reordering) |
| `Z` | Step size |
| `D` | Loop variable (current Fahrenheit value) |
| `C` | Celsius result |
| `K` | Kelvin result (also reused as decoration RND seed at line 30) |
| `H` | Second decoration CHR$ offset |
| `S`, `U` | Loop counters for decoration loops |

### Notable Anomalies

- Variable `K` is used first as a decoration seed (line 30) and then overwritten as the Kelvin temperature (line 320). This is harmless but slightly confusing.
- Line numbers 80–110 and 240 are absent, suggesting the program was edited and some lines deleted.
- The loop at line 300 runs to `E+Z` rather than `E`, which means the table always includes one extra row beyond the requested upper bound.
- The `SAVE "1005%0"` at line 357 (where `%0` is an inverse `0`) is an auto-run save; line 360 then immediately `RUN`s the program, creating a continuous loop.

## Source Code

```
   5 REM CONVERSION PROGRAM
  10 RAND 
  20 PRINT "     A DEGREE OF CONVERSION"
  30 LET K=10*RND
  40 FOR S=1 TO 32
  50 PRINT CHR$ (K+128);
  60 NEXT S
  70 PRINT AT 5,0;"WHAT IS THE LOWEST TEMP,(F)YOU"
 120 PRINT "WANT TO CONVERT?"
 130 INPUT A
 140 PRINT ,"AND HIGHEST?"
 150 INPUT B
 160 IF B<A THEN LET E=A
 170 IF A<B THEN LET F=A
 180 IF B<A THEN LET F=B
 190 IF A<B THEN LET E=B
 200 PRINT "IN WHAT DEGREE STEPS?"
 210 INPUT Z
 220 CLS 
 230 PRINT TAB 8;"F","C";TAB 24;"K"
 250 LET H=10*RND
 260 FOR U=1 TO 21
 270 PRINT CHR$ (H+128);
 280 NEXT U
 290 PRINT 
 300 FOR D=F TO E+Z STEP Z
 310 LET C=5*(D-32)/9
 320 LET K=C+273
 330 PRINT TAB 8;D,C;TAB 24;K
 350 NEXT D
 357 SAVE "1005%0"
 360 RUN
```