| Paradigm(s) | imperative |
|---|---|
| Appeared in | 1984 |
| Designed by | ? |
| Developer | Microsoft Corporation |
| Stable release | 4.1 (?) |
| Typing discipline | ? |
| Major implementations | ? |
| Dialects | ? |
| Influenced by | GW-BASIC |
| Influenced | Vilnius BASIC |
| OS | Optional; Any suitable OS is O.K. |
| License | MS-EULA |
| Website | www.microsoft.com |
MSX BASIC is a dialect of the BASIC programming language. It is an extended version of Microsoft Standard BASIC Version 4.5, and includes support for graphic, music, and various peripherals attached to MSX Personal Computers. Generally, MSX-BASIC is designed to follow GW-BASIC, which is one of the standard BASICs running on 16-bit computers.[1] During the creation of MSX-BASIC, a major effort was made to make the system as flexible and expandable as possible.
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MSX BASIC came bundled in the ROM of all MSX computers. At system start-up MSX BASIC is invoked, causing its command prompt to be displayed, unless other software placed in ROM takes control (which is the typical case of game cartridges and disk interfaces, the latter causing the MSX-DOS prompt to be shown if there is a disk present which contains the DOS system files).
When MSX BASIC is invoked, the ROM code for BIOS and the BASIC interpreter itself are visible on the lower 32K of the Z80 addressing space. The upper 32K are set to RAM, of which about 23K to 28K are available for BASIC code and data (the exact amount depends on the presence of disk controller and on the MSX-DOS kernel version).
MSX BASIC development environment is very similar to that of the Dartmouth Time Sharing System associated with Dartmouth BASIC. It has a command line-based Integrated Development Environment (IDE) system; all program lines must be numbered, all non-numbered lines are considered to be commands in direct mode (i.e., to be executed immediately). The user interface is almost completely command line, except for the function key shortcuts at the bottom and an initial copyright notice at the top of the screen.
Every new version of the MSX computer was bundled with an updated version of MSX BASIC. All versions are backward compatible and provide new capabilities to fully explore the new and extended hardware found on the newer MSX computers.
MSX BASIC 2.1 exists on computers Yamaha YIS-805[2] and Sanyo MPC-2300[3] with Cyrillic keyboard and Cyrillic symbols support.
Since MSX BASIC was meant to be expandable from inception, it was possible to write add-on modules quite easily. Support for specific hardware was commonly added by means of expansion cartridges, which also served as the interface to the hardware in question. MSX Disk-BASIC is an example, bundled in the cartridge that provides the hardware interface to the disk drives, it adds commands to access the floppy disk drives.
Exploring the MSX BASIC extensibility it was possible to extend MSX BASIC solely via software. A very interesting extension to the MSX BASIC 1.0/1.1 was Screen IV, a tweak of MSX BASIC adding the mixed graphic/text mode Screen 4 (hence its name Screen IV), with 64 x 24 characters and Screen 2 resolution for graphics (256 x 192 pixels, 16 colors).