---
title: "Memory Decoding Above 16K"
type: "article"
slug: "memory-decoding-above-16k"
url: "http://localhost/article/memory-decoding-above-16k/"
markdown_url: "http://localhost/article/memory-decoding-above-16k.md"
published_at: "2020-10-27T17:11:10+00:00"
modified_at: "2024-06-23T01:09:33+00:00"
featured_image:
  url: "http://localhost/wp-content/uploads/2022/04/20230809-041332.jpg"
excerpt: "Sinclair made the ZX81 RAM easy to decode up to 16K, but you may want to add memory beyond this point. To add more than 16K memory to your ZX80/81, you must do more than just: /A13 AND /A14 AND /A15 = /ROM CS. You’ll also need to account for the behavior of the display…"
category:
  - name: "Syntax"
    slug: "syntax"
    taxonomy: "category"
    url: "http://localhost/category/periodicals/syntax/"
post_tag:
  - name: "1982"
    slug: "year-1982"
    taxonomy: "post_tag"
    url: "http://localhost/tag/year-1982/"
  - name: "Hardware project"
    slug: "hardware-project"
    taxonomy: "post_tag"
    url: "http://localhost/tag/hardware-project/"
  - name: "ZX80"
    slug: "zx80"
    taxonomy: "post_tag"
    url: "http://localhost/tag/zx80/"
  - name: "ZX81"
    slug: "zx81"
    taxonomy: "post_tag"
    url: "http://localhost/tag/zx81/"
model:
  - name: "Sinclair ZX80"
    slug: "zx80"
    taxonomy: "model"
    url: "http://localhost/model/zx80/"
  - name: "Sinclair ZX81"
    slug: "zx81"
    taxonomy: "model"
    url: "http://localhost/model/zx81/"
indiv:
  - name: "John Oliger"
    slug: "john-oliger"
    taxonomy: "indiv"
    url: "http://localhost/indiv/john-oliger/"
publication: "Syntax"
publication_r:
  id: 10246
  title: "Syntax"
  type: "periodical"
  url: "http://localhost/periodical/syntax/"
authors: "John Oliger"
volume: "3"
issue: "5"
issues_articles:
  - id: 26704
    title: "Syntax/Syntax ZX80 v3 n5"
    type: "issue"
    url: "http://localhost/issue/syntax-syntax-zx80-v3-n5/"
pages: "5"
pubdate: "May 1982"
archive_link: false
volumeissue: "v3n5"
---

Sinclair made the ZX81 RAM easy to decode up to 16K, but you may want to add memory beyond this point. To add more than 16K memory to your ZX80/81, you must do more than just: /A13 AND /A14 AND /A15 = /ROM CS. You’ll also need to account for the behavior of the display file.