This site contains the source code for two different variants of the BBC Micro disc version of Elite:
- The variant from the Stairway to Hell archive
- The variant from the game disc on Ian Bell's website
See below for comprehensive details of the differences between the variants, along with links to the relevant bits of the source code.
All these differences are implemented within the source code using BeebAsm IF statements, which determine which variant is compiled. These IF statements check the values of the relevant source code variables (_STH_DISC and _IB_DISC), which are themselves set by parameters to the build command (such as variant=ib-disc). See the associated repository for more about building different variants from the source.
Note that in the following, I have only included differences that appear in the main game code, rather than those that appear in the loaders, as these files can differ extensively between variants without affecting the game itself. The variant on Ian Bell's site contains a whole load of copy protection differences when compared to the same code in the Stairway to Hell variant, and it also contains two more binary files (ELITE5 and ELITE6), plus a !BOOT file that contains even more copy protection code. I haven't disassembled the loader files from this variant as that's a whole different rabbit hole.
To play Elite with an SSD disc image, load the BBC Micro disc image into drive 0 and press SHIFT-BREAK.
The Stairway to Hell variant
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The variant in the Stairway to Hell archive is a cracked version of the original Acornsoft release. It has all the known bugs fixed and the copy protection is disabled, so this looks like the second release of BBC Micro disc Elite. The same variant was later released as part of the multi-version SNG47 release.
| Default build in repository | Yes |
| Product details | Acornsoft SNG38 Acornsoft SNG47 |
| Date | 1984 |
| Build command parameter | variant=sth (optional) |
| Source code variable | _STH_DISC |
| Verification checksums (crc32) | See the GitHub repository |
| Download SSD disc image | Original, Flicker-free, Music |
| Play this variant online | Original, Flicker-free, Music |
It has the following features that differentiate it from the other variants:
- Bit 5 is set in the version number in the competition flags (see DFAULT).
The game disc on Ian Bell's site
--------------------------------
The variant on Ian Bell's site appears to be the very first release of BBC Micro disc Elite. The binaries match the very first Acornsoft release (with the refund and asteroid bugs), so this looks like the original disc variant.
| Default build in repository | No |
| Product details | Acornsoft SNG38 |
| Date | 1984 |
| Build command parameter | variant=ib-disc |
| Source code variable | _IB_DISC |
| Verification checksums (crc32) | See the GitHub repository |
| Download SSD disc image | Original, Flicker-free |
| Play this variant online | Original, Flicker-free |
It has the following features that differentiate it from the other variants:
- The refund bug is present (see refund).
- Asteroids are never spawned (see Main game loop part 2).
- Bit 2 is set in the version number in the competition flags (see DFAULT).
- The docked code's workspace noise is different (see Checksum).