Description

BLS is a image viewer created by Seiga. BLS is a classic multi-format image viewer application for the MSX-DOS.

BLS has been enhanced by FRS. The latest version of it is the v3.0A.

Features

• A simple built-in file manager
• Joystick support
• 7 different variations of the MSX1 palette to try
• A direct mode to view files from the command line, without having to open the built-in file manager
• Full support for the NEOS MA-20 "Version Up Adapter"
• Subdirectory support on MSX-DOS2/Nextor
• Can convert SCREEN12 images to SCREEN8 on the fly, with high-res interlaced dithering
• Downscaling and aspect ratio adjustment for images from other platforms

Supported image formats

• MSX BLOAD image format (.SCx): The well-known MSX-BASIC image format that require no introductions. The .PIC files saved by Philips Video Graphics and Matsushita Video Graphics will be automatically recognized as .SC8 by their header. BLS3 added the missing support for .SC2 to .SC4.
• MSX Interlaced BLOAD images (.SCx+.S1x files, optionally .S0x+.S1x): dual file BLOAD image used to display with interlace, for 424 lines of resolution
• Graph Saurus screen images (.SRx+.PLx / .SRI+.PL7). Another very popular MSX image format that, when not compressed or interlaced, is just a variation of the BLOAD image format with an external palette file containing 8 independent 16-color palettes. BLS3 now also supports the compressed and interlaced .SRx variations.
• MSX2 COPY images (.SHx, .GLx). It's the file format used by the MSX-BASIC for images smaller than the screen (also called shapes). An optional .PLx file containing a single or eight 16-color palettes is usually paired to customize the colors of the image.
• QLD format (.GRA): This is a little known image format with 8 fixed colors that was used on some Japanese BBSs
• Makichan v1 (.MKI): An early Japanese image format that was quickly succeeded by the v2. It's mostly PC-98 oriented, with some rudimentary support for other platforms
• Makichan v2 (.MAG): It was by far the most popular Japanese legacy image format, with support for multiple platforms including the MSX2/2+. Achieves excellent compression ratios on par with the GIF format, and was widely used on MSX disk magazines in the 90s.
• Yanagisawa's PIC: Another Japanese multi-platform image format, mostly used on the Sharp X68000 due to its support for high-color. It also achieves excellent compression ratios, but was rarely used for MSX images.
• Dynamic Publisher. This was a desktop publishing app for the MSX2. It used three different file types:
  • Page files (.PCT)
  • Font files (.FNT)
  • Stamp files (.STP, it's a synonym for .SHx)
• Sega Bitmap (.SBM): Image format used to store VRAM dumps of the Sega consoles: SG-1000, Sega Master System and Game Gear
• ZX-Spectrum image (.SCR): Image format widely used to store VRAM dumps of the UK ZX-Spectrum computer.
• Text files are also supported (.TXT, .DOC, .DIZ, .HED, .HIS, .ENG), with either ASCII or Shift_JIS encoding

Requirements

• MSX2 or higher with 64KB or more of RAM and 64KB or more of VRAM (128KB of VRAM is required for SCREEN7/higher and the TextViewer)
• MSX-DOS1 and MSX-DOS2(/Nextor), with subdirectory support on the latter

Limitations and known bugs

• MSX2 machines with 64KB of VRAM will show garbage if any screen mode that requires 128KB of VRAM is used, or on the TextViewer
• MAG:
  • The scroll is being set one line above than it should for some files.
  • Some horizontal banner images will only be shown left-justified.
  • Banner images taller than 256 lines can only be scrolled up to their last 256 lines.
  • There's no horizontal scroll yet. The image will be redrawn cropped to the left, center or right.
• PCT: No support for scrolling yet. The whole image is already loaded to the VRAM though.
• SCx: Some images saved by MIFui have an incorrect size value on the BLOAD header. This will result in spurious sprites showing up for those images in gallery mode. It's not a bug on BLS.COM
• Depending on the palette, the filename text might be unreadable on SCR4 to SCR7.
• When the Z option, used to display PIC images in grayscale, is requested for 16-color images, only the first half of the colors will be displayed in grayscale.
• MSX2+ to MSX2 conversion:
  • The SCREEN10/11 are treated SCREEN12. This means that the colors will look off, but it's still better on an MSX2 than without any conversion.
  • Vertical banner images are not fully supported. Only parts of the image will be converted
• PIC: Native MSX images are accepting the dithering/force-SCR12 parameters (and respective keys D/C on the viewer), when they shouldn't, resulting in incorrect conversions