Software

SPECTRA Image Converter

The SPECTRA Image Converter utility is a .NET application that runs on Microsoft Windows and allows images (in a range of popular formats) to be converted into any of the attribute modes supported by the SPECTRA interface and then saved out in a variety of forms. It was used to create the range of screenshots shown in the Screen Gallery. The SPECTRA Image Converter utility is shown below:

The utility allows an image file (in either .BMP, .GIF, .PNG, .JPG or .TIFF format) to be loaded (using the toolbar, menu, via drag and drop, or right click and Paste) and automatically converts it into the selected SPECTRA attribute mode (as specified by the Attribute Size, Colours and Encoding Size options). Dithering may be applied, which aims to produce a more accurate colour representation of the original image. Images are automatically scaled to 256 by 192 pixels upon loading.

The converted image can be saved (using the toolbar or menu) in the following formats:

• Binary
• Tape
• Assembler
• Image

Binary generates a file containing the bytes from the display and attribute files, with any regions between them filled with bytes of $FF to form a contiguous block. The format supports a sub-option to include a Display Program. This is a small machine code routine that loads the data into the display and attribute files and switches the SPECTRA interface into the appropriate attribute mode. If the Display Program is included then sub-option Target ROM is available to configure the program to run from ROM space (address $0000) instead of RAM (address $8000). This allows the program to be run from a ZXC2, ZXC3 or ZXC4 ROM cartridge, created using the ZX Cartridge Creator utility. When targetting the ROM space, the attribute file data is stored immediately after the display file data, and hence there are no regions of $FF bytes inserted. The Display Program allows the flash bits of every attribute file byte to be exercised. When displaying an image using a single byte attribute mode, pressing key F will toggle the flash bits. When displaying an image using a double byte attribute mode, pressing key I or P will toggle the ink and paper flash bits respectively.

Tape generates a virtual cassette file which, via a Spectrum emulator, can be saved to a real cassette and then loaded into a Spectrum (which has a SPECTRA interface attached). The sub-option to include the Display Program is available and functions as described above. The virtual cassette file can be created in either .TAP or .TZX format.

Assembler generates an assembly language version of the Binary output. Sub-options to include the Display Program and Target ROM are available and function as per the Binary output format. Two other sub-options are also available. The sub-option Tab Indent selects whether to indent each assembly language instruction with a single tab character or with 8 spaces. The sub-option Lower Case specifies whether the assembly language instructions and labels are output in lower case or upper case.

Image allows the converted image to be saved as either a .BMP, .GIF, .PNG, .JPG or .TIFF file. The image can also be copied to the Windows clipboard by right clicking on it and selecting Copy.

The SPECTRA Image Converter utility also allows the number of colours used in the original or converted image to be determined by right clicking on the images and selecting Properties. A description of the output file format options can be displayed by clicking on the 'i' symbol located on the toolbar.

Click here to download the SPECTRA Image Converter [V1.1.0].