---
title: "Zone Selection"
type: "article"
slug: "zone-selection"
url: "http://localhost/article/zone-selection/"
markdown_url: "http://localhost/article/zone-selection.md"
published_at: "2022-10-07T12:24:07+00:00"
modified_at: "2024-05-26T13:32:28+00:00"
featured_image:
  url: "http://localhost/wp-content/uploads/2022/04/20230809-041332.jpg"
excerpt: "Program successively adds 232 and 10 to the DATA value. If the initial value is > 23, the first addition results in a sum > 255; therefore a carry. If 13 < data < 24, then the second addition gives a carry, If data < 16, then no carry at all. BC is originally loaded…"
category:
  - name: "ISTUG Newsletter"
    slug: "istug-newsletter"
    taxonomy: "category"
    url: "http://localhost/category/periodicals/istug-newsletter/"
post_tag:
  - name: "Machine language programming"
    slug: "machine-language"
    taxonomy: "post_tag"
    url: "http://localhost/tag/machine-language/"
  - name: "TS 1000"
    slug: "ts1000"
    taxonomy: "post_tag"
    url: "http://localhost/tag/ts1000/"
  - name: "Tutorial"
    slug: "tutorial"
    taxonomy: "post_tag"
    url: "http://localhost/tag/tutorial/"
  - name: "Type-in program"
    slug: "type-in-program"
    taxonomy: "post_tag"
    url: "http://localhost/tag/type-in-program/"
model:
  - name: "Timex/Sinclair 1000"
    slug: "ts-1000"
    taxonomy: "model"
    url: "http://localhost/model/ts-1000/"
indiv:
  - name: "John (Basil) Wentworth"
    slug: "john-basil-wentworth"
    taxonomy: "indiv"
    url: "http://localhost/indiv/john-basil-wentworth/"
publication_r:
  id: 39269
  title: "ISTUG Newsletter"
  type: "periodical"
  url: "http://localhost/periodical/istug-newsletter/"
authors: "John (Basil) Wentworth"
issues_articles:
  - id: 39792
    title: "ISTUG Newsletter Feb 1987"
    type: "issue"
    url: "http://localhost/issue/istug-newsletter-feb-1987/"
pages: "2"
pubdate: "February 1987"
archive_link: false
---

# Zone Selection

Program successively adds 232 and 10 to the DATA value. If the initial value is > 23, the first addition results in a sum > 255; therefore a carry. If 13 < data < 24, then the second addition gives a carry, If data < 16, then no carry at all. BC is originally loaded with 58 and is incremented twice, once, or zero times, according to how many carries take place.