Vector graphics for the ZX81

Discussion about ZX80 / ZX81 Software
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bbock
Posts: 53
Joined: Wed Jan 12, 2011 7:59 pm

Vector graphics for the ZX81

Post by bbock »

SVG (= Scalable Vector Graphics) is the standard format for vector graphics on the Internet. Unfortunately, this format is too complex to be displayed directly on 8-bit computers like the ZX81. My Java program TinySVG extracts "line drawings" from SVG files and converts them into simplified vector formats for retro computers. For the ZX81, it can create .p files that contain the vector data in a REM line. It uses the high-resolution graphic HRG-ms by Matthias Swatosch: http://www.swatosch.de/zx81/index.html.

The current version of TinySVG can be found here: https://joyceforum.de/viewtopic.php?f=5&t=65&start=20

A small manual:
  • Start TinySVG.jar with a double click (Java Runtime version 8 or higher required).
  • Under Options > Configuration the following items should be activated: Center, Resize, Bézier curve approximation, Arc approximation, Activate line reducer. To set the Output files and Screen resolution sections, simply choose "ZX81" under Presets.
  • File > Open > Select SVG file
  • The .p file can be found in the same directory as the SVG file, but with the extension .p (e.g. laempel.svg -> laempel.p).
SVG.zip
Some SVG files to try out
(637.43 KiB) Downloaded 32 times

The vector graphics can be drawn on a real (HRG capable) ZX81 or in the emulator.

Settings in EightyOne:
  1. Options > Hardware or F6
  2. Register "Sinclair"
  3. Select ZX81
  4. RAM Pack: set to 48k
  5. Tab "Interfaces": Set High Resolution to "WRX"
  6. Tab "Advanced Settings": Activate "Enable M1Not Circuit"
Load the graphic in EightyOne:
  1. Tape Manager via Tools > Activate Tape Manager
  2. Deactivate the "Auto LOAD on insert" button in the Tape Manager (top right); "Flash Load" and "Auto Start/Stop" remain on.
  3. File > Open Tape > Select hrg-64k.p
  4. LOAD "" -> the HRG-ms start screen appears
  5. Press spacebar -> HRG shows to which memory area it was loaded, e.g. "OK. HRG LOADED TO 30144"
  6. In the Tape Manager, click on the Open button and select the .p file.
  7. In the EightyOne main window enter LOAD "".
  8. Enter RUN
User avatar
bbock
Posts: 53
Joined: Wed Jan 12, 2011 7:59 pm

Re: Vector graphics for the ZX81

Post by bbock »

The following SVG files can be used in TinySVG, too, showing some nice "impossible figures":

Figuren.zip
Impossible figures
(6.43 KiB) Downloaded 27 times
User avatar
bbock
Posts: 53
Joined: Wed Jan 12, 2011 7:59 pm

Re: Vector graphics for the ZX81

Post by bbock »

A few teaser pictures:

Sinclair-ZX81.png
Sinclair-ZX81.png (4.11 KiB) Viewed 422 times
laempel.png
laempel.png (10.85 KiB) Viewed 422 times
leopard-lilly.png
leopard-lilly.png (3.18 KiB) Viewed 422 times
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