| Developer: | Mike Leaman |
| Latest Release Version: | YSMegaBasicV4.0 |
| Operating System: | ZX Spectrum |
| Genre: | BASIC programming language interpreter |
| License: | Proprietary |
YS MegaBasic is a BASIC programming language interpreter for the 1982 Sinclair Research ZX Spectrum microcomputer, written by Mike Leaman.[1] The interpreter was available by mail-order from Your Spectrum magazine, hence the name "YS MegaBasic".
When loaded it left the user 22K of usable memory. YS MegaBasic allowed keywords to be spelled out letter-for-letter, which was quicker if the user had fitted a full-size full-travel keyboard to their machine, a very popular modification for serious users. This also removed the necessity for memorising the sometimes arcane key combinations necessary to enter less-commonly-used Sinclair BASIC keywords. It also featured three different font sizes, user definable keys, copy-and-paste, a Sinclair QL-like windowing system, sprites and sound effects.[1]
New commands added by YS MegaBasic:
| AUTO | Causes the computer to automatically produce line numbers | |
| BACKUP | Copies tape files | |
| CHANGE | Manipulates the attributes file | |
| CLW | Clears the current window on-screen | |
| CURRENT | Changes the window used for screen output | |
| DELETE | Erases a block of program lines | |
| DOWN | Prints a string down the screen | |
| EDIT | Displays a program line for editing | |
| EXAMINE | Displays headers of tape files | |
| FADE | Produces special effects on-screen | |
| FONT | Selects the character set used for printing | |
| FX | Handles miscellaneous functions | |
| INVERT | Changes INK to PAPER and vice versa | |
| KEY | Creates user-defined keys | |
| MODE | Changes the current character size | |
| MON | Jumps to front panel | |
| PAN | Scrolls a window to the left or right, pixel by pixel | |
| PLAY | Produces complex sound effects | |
| RESTART | Equivalent to ON ERROR GO TO | |
| SPEED | Used in conjunction with TRON to reduce the speed of program execution | |
| SWAP | Swaps one attribute for another | |
| TROFF | Turns 'trace' mechanism off | |
| TRON | Turns 'trace' mechanism on | |
| VDU | Equivalent to PRINT CHR$ | |
| WINDOW | Defines the size and location of the current window on-screen |