Anonymous user
Category:Locomotive Basic: Difference between revisions
→Features: screen modes
No edit summary |
(→Features: screen modes) |
||
Line 16:
Locomotive BASIC was comparatively advanced for its time (with e.g. software interrupts and comprehensive graphics and audio commands) and is very cleanly implemented, just like the rest of the Amstrad CPC ROM. No doubt this was partly because the CPC debuted relatively late during the era of 8-bit machines, so Locomotive Software had more of an opportunity to consider the good and bad software design decisions in existing home computers. System calls are made with <tt>CALL</tt> via dedicated jump blocks in RAM, so they are unaffected by changes to the ROM between CPC models. This makes software very compatible between the original three CPC models and ''mostly'' compatible for the later, considerably less popular "Plus" models that came out in 1990. Together with AMSDOS, the '''Ams'''trad '''D'''isk '''O'''perating '''S'''ystem, Locomotive BASIC is also used for disk and tape operations. (Some commands however, e.g. <tt>disckit3</tt> for formatting disks, are only available under CP/M.)
===Screen modes===
*mode 0: 160x200 pixels, 16 colors, 20x25 characters
*mode 1: 320x200 pixels, 4 colors, 40x25 characters
*mode 2: 640x200 pixels, 2 colors, 80x25 characters
*mode 3 (CPCBasic only!): 640x400 pixels, 16 colors, 80x50 characters
Pixels are addressed in physical units from BASIC, i.e. the center of the screen is always at 320, 200 and the top right corner is always at 639, 399, regardless of selected mode.
==Z80 Extensions==
| |||