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Elite on the BBC Micro

Version analysis of BR1 (Part 2 of 2)

This code appears in the following versions (click to see it in the source code):

Code variations between these versions are shown below.

Name: BR1 (Part 2 of 2) Type: Subroutine Category: Start and end Summary: Show the "Load New Commander (Y/N)?" screen and start the game
BRKV is set to point to BR1 by the loading process.
JSR msblob \ Reset the dashboard's missile indicators so none of \ them are targeted

Code variation 1 of 2Related to a standard feature

On the second title page (the one that says "Press Space Or Fire,Commander"), the cassette and Electron versions show a rotating Mamba, the disc version shows a rotating Krait, the 6502SP version shows a rotating Asp Mk II, and the Master version shows a rotating Cougar.

Tap on a version to expand it, and tap it again to show to all variations.

Cassette, Electron

Docked

Master

6502SP

LDA #147 \ Call TITLE to show a rotating Mamba (#3) and token LDX #3 \ 147 ("PRESS FIRE OR SPACE,COMMANDER.{crlf}{crlf}"), JSR TITLE \ returning with the internal number of the key pressed \ in A
LDA #7 \ Call TITLE to show a rotating Krait (#KRA) and token LDX #KRA \ 7 ("PRESS SPACE OR FIRE,{single cap}COMMANDER.{cr} JSR TITLE \ {cr}"), returning with the internal number of the key \ pressed in A
LDA #7 \ Call TITLE to show a rotating Cougar (#COU) and LDX #COU \ token 7 ("LOAD NEW {single cap}COMMANDER {all caps} LDY #100 \ (Y/N)?{sentence case}{cr}{cr}""), with the ship at a JSR TITLE \ distance of 100, returning with the internal number \ of the key pressed in A
LDA #7 \ Call TITLE to show a rotating Asp Mk II (#ASP) and LDX #ASP \ token 7 ("LOAD NEW {single cap}COMMANDER {all caps} JSR TITLE \ (Y/N)?{sentence case}{cr}{cr}""), returning with the \ internal number of the key pressed in A
 JSR ping               \ Set the target system coordinates (QQ9, QQ10) to the
                        \ current system coordinates (QQ0, QQ1) we just loaded

Code variation 2 of 2Specific to an individual platform

The 6502SP version inlines the code from the hyp1 routine here, instead of calling it (though it could just as easily call it, as the hyp1 routine is included in the 6502SP version and contains the same code).

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Cassette, Docked, Electron

6502SP, Master

JSR hyp1 \ Arrive in the system closest to (QQ9, QQ10) and then \ fall through into the docking bay routine below
JSR TT111 \ Select the system closest to galactic coordinates \ (QQ9, QQ10) JSR jmp \ Set the current system to the selected system LDX #5 \ We now want to copy the seeds for the selected system \ in QQ15 into QQ2, where we store the seeds for the \ current system, so set up a counter in X for copying \ 6 bytes (for three 16-bit seeds) \ The label below is called likeTT112 because this code \ is almost identical to the TT112 loop in the hyp1 \ routine .likeTT112 LDA QQ15,X \ Copy the X-th byte in QQ15 to the X-th byte in QQ2, STA QQ2,X DEX \ Decrement the counter BPL likeTT112 \ Loop back to likeTT112 if we still have more bytes to \ copy INX \ Set X = 0 (as we ended the above loop with X = &FF) STX EV \ Set EV, the extra vessels spawning counter, to 0, as \ we are entering a new system with no extra vessels \ spawned LDA QQ3 \ Set the current system's economy in QQ28 to the STA QQ28 \ selected system's economy from QQ3 LDA QQ5 \ Set the current system's tech level in tek to the STA tek \ selected system's economy from QQ5 LDA QQ4 \ Set the current system's government in gov to the STA gov \ selected system's government from QQ4 \ Fall through into the docking bay routine below
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