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Different variants of the 6502 Second Processor version

This site contains the source code for three different variants of the 6502 Second Processor version of Elite:

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 (_SNG45, _SOURCE_DISC and _EXECUTIVE), which are themselves set by parameters to the build command (such as variant=executive). See the associated repository for more about building different variants from the source.

To play Elite with an SSD disc image, load the disc image into drive 0 and press SHIFT-BREAK.

The official Acornsoft SNG45 release
------------------------------------

This variant was the first official release of 6502 Second Processor Elite, as Acornsoft SNG45. The same variant was later released as part of the multi-version Acornsoft SNG47 release.

Default build in repositoryYes
Product detailsAcornsoft SNG45
Acornsoft SNG47
Date1985
Build command parametervariant=sng45 (optional)
Source code variable_SNG45
Verification checksums (crc32)See the GitHub repository
Download SSD disc imageOriginal, Flicker-free
Play this variant onlineOriginal, Flicker-free

Ian Bell's source disc
----------------------

The source disc from Ian Bell's site contains a subtly different variant of the official Acornsoft SNG45 release. This was never released.

Default build in repositoryNo
Product details-
Date1985
Build command parametervariant=source-disc
Source code variable_SOURCE_DISC
Verification checksums (crc32)See the GitHub repository
Download SSD disc imageOriginal, Flicker-free
Play this variant onlineOriginal, Flicker-free

It has the following features that differentiate it from the other variants:

  • There is a new extended system description override for Lave (see RUPLA, RUGAL and RUTOK). It's the rather cryptic "Bits'n Pieces - End Of Part 1", whatever that means.
  • The top laser line in the source disc version aims slightly lower than in the SNG45 version (see LASLI).
  • The loader contains a long and rather involved check for Tube hardware, which was removed for the official release (see loader).
  • The copyright string that's buried in the SNG45 and Executive loaders is missing (see copyright).

The Executive version
---------------------

The Executive version, which is available from Ian Bell's site, was also never released. It has loads of unique features.

Default build in repositoryNo
Product details-
Date1985?
Build command parametervariant=executive
Source code variable_EXECUTIVE
Verification checksums (crc32)See the GitHub repository
Download SSD disc imageOriginal, Flicker-free
Play this variant onlineOriginal, Flicker-free

It has the following features that differentiate it from the other variants:

  • The memory map is slightly different: the K% workspace is bumped up from &8200 to &8500, the LP workspace is bumped up from &8600 to &8900, and the parasite variables workspace is two bytes bigger to cater for the two new configuration options.
  • There are new extended system description overrides for Lave and Riedquat (see RUPLA, RUGAL and RUTOK):
    • Lave: "This message is available only on the executive version of this program"
    • Riedquat: "Only this executive version has the @ toggle"
  • There are two new configurations settings that can be toggled when the game is paused: "@" toggles infinite jump range, and ":" toggles speech (see DKS3 and DK4 for the key-handling code, and the parasite variables for the new configuration variables).
  • Infinite jump range enables jumps to be made anywhere in the galaxy, without using any fuel (see hyp for the infinite jump range, and TT18 for the infinite fuel).
  • Speech is supported with the Watford Electronics Beeb Speech Synthesiser (see TALK and SPEECH for the speech code):
    • If speech is enabled, CHPR doesn't make beep noises (though BELL still does, so CONT 7 characters in recursive text tokens still make a beep, for example).
    • It says "Elite" when displaying the title screen (see part 1 of BR1).
    • It repeatedly says "Energy low" when energy is low (see part 15 of the main flight loop).
    • It says "Oh shit, it's a mis-jump" on a mis-jump (see MJP).
    • It repeatedly says "Incoming missile" when a missile is incoming (see SFRMIS).
  • Unlike the other versions, the Executive version's loader does not disable hardware interrupts from the User VIA, as this would disable the speech synthesiser that connects via the user port (see STARTUP).
  • The demo starts automatically when loading finishes (see TT170).
  • The scroll text in the demo is different (see DEMON). The new text is as follows:
    • PIZZASOFT PRESENTS (see acorn)
    • THE EXECUTIVE VERSION (see executive)
    • CONGRATULATIONS ON OBTAINING A COPY OF THIS ELUSIVE PRODUCT (see true3)
  • The Executive version has a unique, retro-futuristic font (see FONT%).
  • There are three changes to the recursive text tokens (see QQ18):
    • Token 35 is "L.Y." instead of "LIGHT YEARS" (which frees up space for the following changes).
    • Token 100 is "ENERGY LOW,SIR{beep}" instead of "ENERGY LOW{beep}".
    • Token 120 is "INCOMING MISSILE,SIR" instead of "INCOMING MISSILE".
  • There is an extra string, "Firebird", buried in the source that doesn't have any effect, but is presumably a reference to the publishers of the non-Acorn versions of Elite (see the Firebird string).
  • The default, starting commander is called Firebud and is maxed-out with loads of cash and a properly kitted-out ship (see NA%, CHK, CHK2).
  • The competition flags at COK have bit 7 set, to indicate that this commander file has been tampered with (see byte #14 in NA%).
  • The top laser line in the Executive version aims slightly lower than in the SNG45 version (see LASLI).
  • The loader contains a long and rather involved check for Tube hardware, which isn't present in the official release (see loader).