---
title: "Designing Operating Systems: A ROM Based O.S. for the Z81"
type: "article"
slug: "designing-operating-systems-a-rom-based-o-s-for-the-z81"
url: "http://localhost/article/designing-operating-systems-a-rom-based-o-s-for-the-z81/"
markdown_url: "http://localhost/article/designing-operating-systems-a-rom-based-o-s-for-the-z81.md"
published_at: "2023-06-26T23:02:08+00:00"
modified_at: "2024-05-26T13:29:21+00:00"
featured_image:
  url: "http://localhost/wp-content/uploads/2022/04/20230809-041332.jpg"
excerpt: "Article describes implementing a smaller operating system, with CP/M as the starting point, on the Sinclair ZX81/TS 1000."
category:
  - name: "The Computer Journal"
    slug: "the-computer-journal"
    taxonomy: "category"
    url: "http://localhost/category/periodicals/the-computer-journal/"
post_tag:
  - name: "CP/M"
    slug: "cp-m"
    taxonomy: "post_tag"
    url: "http://localhost/tag/cp-m/"
  - 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/"
indiv:
  - name: "Clark Calkins"
    slug: "clark-calkins"
    taxonomy: "indiv"
    url: "http://localhost/indiv/clark-calkins/"
publication_r:
  id: 10251
  title: "The Computer Journal"
  type: "periodical"
  url: "http://localhost/periodical/the-computer-journal/"
authors: "Clark Calkins"
issue: "32"
pages: "18-19"
download: "https://archive.org/download/clark-a-calkins/ZCPM.zip"
archive_link: false
archiveurl: "https://archive.org/details/the-computer-journal-32/page/n19/mode/1up"
---

# Designing Operating Systems: A ROM Based O.S. for the Z81

Article describes implementing a smaller operating system, with CP/M as the starting point, on the Sinclair ZX81/TS 1000.