---
title: "Blank the Screen"
type: "article"
slug: "blank-the-screen"
url: "http://localhost/article/blank-the-screen/"
markdown_url: "http://localhost/article/blank-the-screen.md"
published_at: "2026-11-11T11:07:31+00:00"
modified_at: "2026-11-11T11:07:31+00:00"
featured_image:
  url: "http://localhost/wp-content/uploads/2022/04/20230809-041332.jpg"
excerpt: "A 68000 assembler program, BLANK_EXE, that blanks the QL's screen after about three minutes without a keypress, to keep a static image from burning into the monitor's phosphor; pressing the space bar brings the screen back. The full commented source is listed, and the author offers the ready-to-use program to readers without an assembler."
post_tag:
  - name: "68000"
    slug: "68000"
    taxonomy: "post_tag"
    url: "http://localhost/tag/68000/"
  - name: "French language"
    slug: "french-language"
    taxonomy: "post_tag"
    url: "http://localhost/tag/french-language/"
  - name: "Machine language programming"
    slug: "machine-language"
    taxonomy: "post_tag"
    url: "http://localhost/tag/machine-language/"
  - name: "QL"
    slug: "ql"
    taxonomy: "post_tag"
    url: "http://localhost/tag/ql/"
  - name: "Type-in program"
    slug: "type-in-program"
    taxonomy: "post_tag"
    url: "http://localhost/tag/type-in-program/"
model:
  - name: "Sinclair QL"
    slug: "sinclair-ql"
    taxonomy: "model"
    url: "http://localhost/model/sinclair-ql/"
indiv:
  - name: "Real Gagnon"
    slug: "real-gagnon"
    taxonomy: "indiv"
    url: "http://localhost/indiv/real-gagnon/"
publication: "QL_DOC"
publication_r:
  id: 52925
  title: "QL_DOC"
  type: "periodical"
  url: "http://localhost/periodical/ql_doc/"
authors: "Réal Gagnon"
issue: "1"
issues_articles:
  - id: 76706
    title: "QL_DOC n1"
    type: "issue"
    url: "http://localhost/issue/ql_doc-n1/"
pages: "1-2"
pubdate: "January 1988"
archive_link: false
volumeissue: "n1"
---

# Blank the Screen

**In English:** A 68000 assembler program, BLANK_EXE, that blanks the QL's screen after about three minutes without a keypress, to keep a static image from burning into the monitor's phosphor; pressing the space bar brings the screen back. The full commented source is listed, and the author offers the ready-to-use program to readers without an assembler.

*The article below is in French, as printed in QL_DOC n1 (January 1988).*

***

Voici un programme qui éteint l’écran après un certain temps d’inactivité du clavier. Ceci est fait pour protéger le phosphore du tube-écran de votre moniteur, en effet si une image reste trop longtemps à l’écran, il se peut que celle-çi brûle le phosphore donnant ainsi naissance à une image fantôme.

Pour démarrer, le programme il faut faire EXEC xxxx_BLANK_EXE . Voilà après environ 3 minutes d’inactivité, l’écran s’éteindra par lui-même, et pour retrouver l’écran, appuyez sur barre d’espace. Si vous ne possédez pas d’ASSEMBLER, envoyez-moi un µdrive/disquette plus 1$ et vous recevrez par le retour du courrier le programme BLANK_ASM prêt à être utilisé.

```
******************************
*    BLANK_EXE  v 0.5        *
* début AOUT87               *
*    par Réal Gagnon         *
******************************

MT_PRIOR   $B                             Routine QDOS qui "set" la priorité
KEY_STATE  $2808A                         Système-variable pour le clavier
           BRA.S BLANK_INIT
           DC.L 4
           DC.W $4AFB
           DC.W 20
           DC.B "BLANK_screen by RG87"
BLANK_INIT MOVEQ #-1,D1                   La priorité de cette job
           MOVEQ #1,D2                    à "1"
           MOVEQ #MT_PRIOR,D0
           TRAP #1                        La trap qui le fait
           LEA.L OLD_KEY,A1               Dernière touche pressée
           MOVE.W (KEY_STATE),D0          La met dans le buffer
           MOVE.W D0,(A1)
BLANK_LOOP MOVE.W OLD_KEY,D0              Dernière touche
           MOVE.W KEY_STATE,D1            Touche nouvelle
           CMP.W D0,D1                    Pareil?
           BNE RESET_OLD_KEY              Si non, on "update"
           LEA.L TEMPS_KEY,A1
           ADDQ.L #1,(A1)                 Si oui, +1
           MOVE.L #$250000,D0
           CMP.L (TEMPS_KEY),D0           A la limite?
           BEQ BLANK_SCR
           BRA BLANK_LOOP

RESET_OLD_KEY   LEA.L OLD_KEY,A1
                MOVE.W D1,(A1)            Nouvelle touche->Ancienne touche
                LEA.L TEMPS_KEY,A1
                MOVEQ.L #0,D0
                MOVE.L D0,(A1)            Compteur à zéro
                BRA BLANK_LOOP            On recommence
BLANK_SCR       MOVEA.L #98403,A1         Eteint l'écran
                MOVEQ.L #2,D0
                MOVE.B D0,(A1)
BLANK_SCR_LOOP  MOVE.W (KEY_STATE),D0
                CMP.W #32,D0
                BEQ UNBLANK_SCR
                BRA BLANK_SCR_LOOP
UNBLANK_SCR     MOVEA.L #98403,A1
                MOVEQ.L #0,D0
                MOVE.B D0,(A1)
                BRA RESET_OLD_KEY
OLD_KEY         DC.W 0
TEMPS_KEY       DC.L 0
                END
```