---
title: "ZX81/TS 1000 Tips"
type: "article"
slug: "zx81-ts-1000-tips"
url: "http://localhost/article/zx81-ts-1000-tips/"
markdown_url: "http://localhost/article/zx81-ts-1000-tips.md"
published_at: "2025-07-27T01:52:23+00:00"
modified_at: "2025-07-27T01:52:24+00:00"
featured_image:
  url: "http://localhost/wp-content/uploads/2022/04/20230809-041332.jpg"
excerpt: "Here is a little function, which may be placed at the beginning or within a machine code program, to stop the program until the tape player starts inputting data. XXXX DBFE HOLD: IN A,(FE) CB7F BIT 7,A 28FA JR Z, HOLD Where XXXX represents the address. This is a routine to set RAMTOP and then…"
category:
  - name: "The Data Expansion"
    slug: "the-data-expansion"
    taxonomy: "category"
    url: "http://localhost/category/periodicals/the-data-expansion/"
post_tag:
  - 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/"
model:
  - name: "Timex/Sinclair 1000"
    slug: "ts-1000"
    taxonomy: "model"
    url: "http://localhost/model/ts-1000/"
indiv:
  - name: "Don Lamen"
    slug: "don-lamen"
    taxonomy: "indiv"
    url: "http://localhost/indiv/don-lamen/"
publication_r:
  id: 50143
  title: "The Data Expansion"
  type: "periodical"
  url: "http://localhost/periodical/the-data-expansion/"
authors_r:
  - name: "Don Lamen"
    slug: "don-lamen"
    taxonomy: "indiv"
    url: "http://localhost/indiv/don-lamen/"
volume: "5"
issue: "3"
issues_articles:
  - id: 50245
    title: "The Data Expansion v5 n3"
    type: "issue"
    url: "http://localhost/issue/the-data-expansion-v5-n3/"
pages: "24"
pubdate: "March 1988"
archive_link: false
---

Here is a little function, which may be placed at the beginning or within a machine code program, to stop the program until the tape player starts inputting data.

```
XXXX  DBFE       HOLD: IN A,(FE)
      CB7F             BIT 7,A
      28FA             JR Z, HOLD
```

Where XXXX represents the address.

This is a routine to set RAMTOP and then install your machine code above it. As an example, let’s say that you have 80 bytes of machines code in 1 REM and you want to install it as address 20000 [7530 hex].