---
title: "ZX81 Programs"
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published_at: "2021-06-26T12:47:58+00:00"
modified_at: "2024-05-26T13:41:29+00:00"
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excerpt: "Several programs from club members. Child1: visual aid to teaching pre-school children numbers from 1 to 10 (Bill Harmer).VROP: voltage regulator circuit design program using a 741 op-amp (Bill Harmer).Screen Fill: short machine language program to fill screen with any single character.Stop-Watch: timer based on internal FRAMES variable; max of 18.2 minutes.Flashing Prompts: demonstration of…"
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  title: "Timex Sinclair User Group Newsletter: Ottawa Chapter"
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volume: "4"
issue: "1"
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    title: "Timex Sinclair User Group Newsletter: Ottawa Chapter v4 n1"
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pages: "4-8"
pubdate: "April 1987"
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---

# ZX81 Programs

Several programs from club members.

- Child1: visual aid to teaching pre-school children numbers from 1 to 10 (Bill Harmer).
- VROP: voltage regulator circuit design program using a [741 op-amp](https://en.wikipedia.org/wiki/Operational_amplifier#741) (Bill Harmer).
- Screen Fill: short machine language program to fill screen with any single character.
- Stop-Watch: timer based on internal FRAMES variable; max of 18.2 minutes.
- Flashing Prompts: demonstration of flashing text.