I have renamed the tool to ZX81 Screen Converter, as it how handles more than BMP files as input.
What is it?
ZX81 Screen Converter is an online tool target preserving ZX81 software for ZXDB, helping to create proper screen shots in formats like s81, scr and png. It take as input a screen dump file and converts to different formats. Allowed input formats:
* .bmp as produced by various emulators (e.g. EightyOne and SZ81)
* .png as produced by the ZX81 emulator for iOS (by Kevin Palser) and Retrospecs (Pixelate your pics!) also for iOS
* .s81 for standard non-hires ZX81 screens (a sequence of 768 character codes from the ZX81 charset)
* .scr widely used screen format used for ZX Spectrum screens, suitable for preserving ZX81 hi-res screens
It will always produce the following output:
* .s81 for standard non-hires ZX81 screens (a sequence of 768 character codes from the ZX81 charset) - if it is a hi-res screen, or the offset parameters is not correct - this will just be garbage.
* .scr for hires screens with regular size (in ZX Spectrum display format)
* .png for big screens, that goes beyond the 256x192 size (for example MaxDemo or QS Defenda)
* .txt for printing in console - mostly for fun (ANSI control codes to implement inverse print) - as with s81, it will be gargabe if hi-res or offset parameters are not aligned to 8x8 blocks. Use this to verify correct offset parameters.
For iOS ZX81 emulator, make sure to have at least v1.9.0 - as this version fixes some issues with the screen dump.
All border sizes from EightyOne with the following sizes are supported:
* No Border: 256x192 pixels
* Small Border: 264x200 pixels
* Standard Border: 320x240 pixels
* Large border: 400x300 pixels
* Full frame: 413x312 pixels
You can find the online converter here:
https://zxinfo.dk/scr/ - and as always, leave a comment here
/Thomas