---
title: "Extensions to Basic"
type: "article"
slug: "extensions-to-basic"
url: "http://localhost/article/extensions-to-basic/"
markdown_url: "http://localhost/article/extensions-to-basic.md"
published_at: "2020-10-27T17:19:15+00:00"
modified_at: "2024-06-23T07:48:26+00:00"
featured_image:
  url: "http://localhost/wp-content/uploads/2022/04/20230809-041332.jpg"
excerpt: "USR routines to invert every character on the screen, print bytes of free memory, create an inverse program listing, and simulate READ, DATA and RESTORE."
category:
  - name: "SYNC"
    slug: "sync"
    taxonomy: "category"
    url: "http://localhost/category/periodicals/sync/"
post_tag:
  - name: "1983"
    slug: "year-1983"
    taxonomy: "post_tag"
    url: "http://localhost/tag/year-1983/"
  - name: "TS 1000"
    slug: "ts1000"
    taxonomy: "post_tag"
    url: "http://localhost/tag/ts1000/"
  - name: "Type-in program"
    slug: "type-in-program"
    taxonomy: "post_tag"
    url: "http://localhost/tag/type-in-program/"
  - name: "ZX81"
    slug: "zx81"
    taxonomy: "post_tag"
    url: "http://localhost/tag/zx81/"
model:
  - name: "Sinclair ZX81"
    slug: "zx81"
    taxonomy: "model"
    url: "http://localhost/model/zx81/"
  - name: "Timex/Sinclair 1000"
    slug: "ts-1000"
    taxonomy: "model"
    url: "http://localhost/model/ts-1000/"
indiv:
  - name: "John Richard Coffey"
    slug: "john-richard-coffey"
    taxonomy: "indiv"
    url: "http://localhost/indiv/john-richard-coffey/"
publication: "Sync"
publication_r:
  id: 10243
  title: "SYNC"
  type: "periodical"
  url: "http://localhost/periodical/sync-magazine/"
authors: "John Richard Coffey"
volume: "3"
issue: "5"
issues_articles:
  - id: 26651
    title: "SYNC v3 n5"
    type: "issue"
    url: "http://localhost/issue/sync-v3-n5/"
pages: "86-89"
pubdate: "September/October 1983"
archive_link: false
volumeissue: "v3n5"
---

# Extensions to Basic

USR routines to invert every character on the screen, print bytes of free memory, create an inverse program listing, and simulate READ, DATA and RESTORE.