---
title: "Modification to Multi-Tasking Article"
type: "article"
slug: "modification-to-multi-tasking-article"
url: "http://localhost/article/modification-to-multi-tasking-article/"
markdown_url: "http://localhost/article/modification-to-multi-tasking-article.md"
published_at: "2026-03-15T00:22:03+00:00"
modified_at: "2026-03-15T00:22:03+00:00"
featured_image:
  url: "http://localhost/wp-content/uploads/2022/04/20230809-041332.jpg"
excerpt: "Correction and addendum to the February 1987 multi-tasking article on IM2 interrupts on the TS2068. Clarifies SCLD chip behavior (places 255 on the bus during interrupts), reducing the needed interrupt table to 2 bytes. Also recommends disabling BIT 6 of port 255 during IM2 initialization, adding NOPs, and ending interrupt service routines with RETI rather…"
category:
  - name: "Timelinez"
    slug: "timelinez"
    taxonomy: "category"
    url: "http://localhost/category/periodicals/timelinez/"
post_tag:
  - name: "TS 2068"
    slug: "ts2068"
    taxonomy: "post_tag"
    url: "http://localhost/tag/ts2068/"
model:
  - name: "Timex/Sinclair 2068"
    slug: "ts-2068"
    taxonomy: "model"
    url: "http://localhost/model/ts-2068/"
indiv:
  - name: "Fred Templeton"
    slug: "fred-templeton"
    taxonomy: "indiv"
    url: "http://localhost/indiv/fred-templeton/"
publication_r:
  id: 21571
  title: "Timelinez"
  type: "periodical"
  url: "http://localhost/periodical/timelinez/"
authors_r:
  - name: "Fred Templeton"
    slug: "fred-templeton"
    taxonomy: "indiv"
    url: "http://localhost/indiv/fred-templeton/"
volume: "5"
issue: "3"
issues_articles:
  - id: 38849
    title: "Timelinez v5 n3"
    type: "issue"
    url: "http://localhost/issue/timelinez-v5-n3/"
pages: "4"
pubdate: "March 1987"
archive_link: false
---

# Modification to Multi-Tasking Article

Correction and addendum to the February 1987 multi-tasking article on IM2 interrupts on the TS2068. Clarifies SCLD chip behavior (places 255 on the bus during interrupts), reducing the needed interrupt table to 2 bytes. Also recommends disabling BIT 6 of port 255 during IM2 initialization, adding NOPs, and ending interrupt service routines with RETI rather than JP.