---
title: "QL Serial to Parallel Converter"
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slug: "ql-serial-to-parallel-converter"
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markdown_url: "http://localhost/article/ql-serial-to-parallel-converter.md"
published_at: "2026-03-15T00:48:42+00:00"
modified_at: "2026-03-15T00:48:42+00:00"
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  url: "http://localhost/wp-content/uploads/2022/04/20230809-041332.jpg"
excerpt: "Full circuit documentation for converting the Sinclair QL's 9600-baud serial RS232 output to Centronics parallel format, enabling use of standard parallel printers. Explains operation of the 74HC02 NOR gate, TL0556 timer, and 74HC164 serial-to-parallel shift register with detailed adjustment instructions for clock frequency (9600 Hz) and frame byte timing. Circuit schematic appears on the cover…"
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  - name: "QL"
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model:
  - name: "Sinclair QL"
    slug: "sinclair-ql"
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    url: "http://localhost/model/sinclair-ql/"
indiv:
  - name: "Rex Lundgren"
    slug: "rex-lundgren"
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    url: "http://localhost/indiv/rex-lundgren/"
publication_r:
  id: 21571
  title: "Timelinez"
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authors_r:
  - name: "Rex Lundgren"
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volume: "7"
issue: "2"
issues_articles:
  - id: 38867
    title: "Timelinez v7 n2"
    type: "issue"
    url: "http://localhost/issue/timelinez-v7-n2/"
pages: "1"
pubdate: "February 1989"
archive_link: false
---

# QL Serial to Parallel Converter

Full circuit documentation for converting the Sinclair QL’s 9600-baud serial RS232 output to Centronics parallel format, enabling use of standard parallel printers. Explains operation of the 74HC02 NOR gate, TL0556 timer, and 74HC164 serial-to-parallel shift register with detailed adjustment instructions for clock frequency (9600 Hz) and frame byte timing. Circuit schematic appears on the cover page.