Make the Spectrum answer

Spectrum BASIC classroom workbook · Learner edition · Version 0.1 · 17 October 2026

Make a small program display words you chose. Predict the result, change one instruction and explain what happened.

One greeting you could make

Hello, explorers!
to you
from the Spectrum

The first message is your choice. This is text output, not a screen capture.

Get ready together

Use a browser and internet connection. A computer with a keyboard gives you room to read and edit. You do not need an original Spectrum or a local installation.

Open code198x.com/try/spectrum-basic/ and follow Open the lesson to Run an editable listing. Use that listing for this workbook. You do not have to type the program into the Spectrum keyboard.

Working in pairs? One person edits and runs; the other predicts and checks. Swap after the first change. You can explain by speaking, writing or drawing.

If the tools will not run, trace the program on paper and mark your answers as predictions. Test them on the machine when you can.

Read, predict and change

The starting program has three stored lines. PRINT displays the text between quotation marks. Each instruction here finishes with a new line.

  10 PRINT "Welcome"
  15 PRINT "to you"
  20 PRINT "from the Spectrum"

Before running: which messages do you expect, and in what order?

Choose Run this code. Compare the result, then choose Back to the listing.

Make one deliberate change

Replace only Welcome in line 10 with your own short greeting. Keep the quotation marks, line number and other two instructions.

Write your changed line 10. Which message should change? Which should stay the same?

Run the edited listing. Swap roles and explain the result to each other.

What appeared? Which instruction explains it?

Try the order experiment

This is an optional extension. You can stop after your first working change.

In the editable text listing, change line number 15 to 25. Keep its message. Leave lines 10 and 20 alone.

This edits the complete listing. Typing a new numbered line directly into a running Spectrum would add that line and leave line 15 stored until you delete it. Use the text listing here.

Predict the three messages in their new running order.

Choose Run this code. Compare before looking for help.

What happened? What decided the order in this program?

If the screen disagrees

Read the error or unexpected output. Point to the first place it differs from your prediction.
Check quotation marks, line numbers and whether you ran the edited listing.
Use When the screen disagrees in the linked lesson. Ask for a hint whenever it helps.

Before the next page, decide whether to keep your reordered program or restore line 25 to 15 in the text listing.

Keep it, then explain it

Copy your complete three-line listing into a plain text file, such as greeting.txt. Save it somewhere you can find again.

Reload the lesson. Open your saved file, copy its full listing and replace the whole editable listing in the lesson. Choose Run this code and check for your chosen words. This tests your kept source, not a fresh example.

You can also open Listing options and choose Download tape to keep a .tap program for an emulator with tape-loading controls. In this browser activity, reopen readable source by pasting it into the listing.

Where did you save it? What did you check when reopening?

Working on paper? Keep your changed listing and record that the machine result is still untested.

Explain what you found

What does PRINT ask the machine to do?

How can one instruction change while the other messages stay the same?

What would you like to try or understand next?

You can stop when your change runs, you can explain it and you have kept a copy. There is no score or fixed time limit.

Adapted from Code Like It's 198x, Make the Spectrum answer and the first-session pack. Original and adapted prose: CC BY 4.0; code samples: MIT, copyright (c) 2025 Code Like It's 198x. Sources and notices are on the final page of the teacher guide and in the accompanying source record.