How BasinC differs from a real Spectrum

BasinC, although as functionally close to being a Sinclair Spectrum on a PC as possible, has several differences. Mostly these affect the way you enter programs into the emulated Spectrum. Firstly, the Spectrum ROM used has been patched extensively to allow new features and bug-fixes, though no changes have been made to the ROM that would affect how your programs would run on a real Spectrum. One example of this is the lack of K, L, C, E, and G cursors - because of the addition of PC keyboard support, these are no longer necessary, as is also the case with the Symbol Shift key. The main cursor in INPUT commands is now a white and blue flashing square, which hovers over the input rather than nestled between tokens. The editor does support the usual text processing operations such as cut, copy, paste and search/replace functions.

Editor and keyboard

Tokens are handled differently too. You no longer enter entire words using a single key-press - the editor is based on the 128k Spectrum, which means full typing support with the available use of every key on a modern keyboard. You are also free to use the mouse to make selections and get context sensitive help. For more information, consult the section devoted to Using the Editor.

As mentioned before, the keyboard does not function as a 48k Spectrum's keyboard would. This means that retrieving key states by reading the result of a BASIC IN instruction from port $FE (254) no longer works. INKEY$ is not affected, however. Machine code instructions that read the keyboard from a Z80 IN opcode will retrieve the correct keys - but the keyboard is significantly different from a PC. The CTRL key is designated to Symbol Shift, the Shift keys act as expected, but bear in mind that CTRL-P will produce a quote (") mark, as opposed to shift-2 on a UK keyboard.

Screen display

The main display output (the Spectrum "screen") has been divorced from the editor and made a standalone window. When a program is running, this window will be where any program output appears. It behaves exactly the same way as a real Spectrum's display. The split display has the benefit that the current program can be traced and debugged at runtime without corrupting the picture. On a related note, runtime errors no longer report to the bottom of the display - they can be redirected to an error dialog which also provides information on that error. This again helps prevent display corruption, but is a feature that can be turned off.

prompts have been enhanced: they use the same blue-and-white cursor as the editor, and they support cut and paste operations.

Loading and saving files

BasinC uses text files with the .bas extension to store BASIC code. This code is in raw text format (windows notepad compatible) with escape codes to represent tokens that cannot be rendered in plain text. See the chapter on .BAS File Format for more details. These files can be used just like tape files on the original hardware - they can store runtime variable contents and auto-start when loaded. Code blocks, such as ones saved with SAVE "foo" CODE address, length are saved either as raw binary bytes, or as BasinC's own format - .bsc files. Similarly, .bsd files are used for SAVE DATA variable blocks. Again, these formats are described elsewhere. Be aware that any SAVE or LOAD command will look for files on your hard disk - and if you specify long filenames with paths included, the resulting program will likely fail to load anything on a real Spectrum. You can work with Tape Image files in BasinC, so it may be worth your while testing on an image before you distribute your work.

See Loading and saving files for more information.