Version analysis of TRNME - Elite on the BBC Micro and NES

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

Cassette, Disc (docked), 6502 Second Processor, Master and Electron

Code variations between these versions are shown below.

       Name: TRNME
       Type: Subroutine
   Category: Save and load
    Summary: Copy the last saved commander's name from INWK to NA%


.TRNME

 LDX #7                 \ The commander's name can contain a maximum of 7
                        \ characters, and is terminated by a carriage return,
                        \ so set up a counter in X to copy 8 characters

Code variation 1 of 2Specific to an individual platform

This variation is blank in the Cassette, Disc (docked), 6502 Second Processor and Electron versions.

Master
 LDA thislong           \ Copy the length of the commander's name from thislong
 STA oldlong            \ to oldlong (though this is never used, so this
                        \ doesn't have any effect)

.GTL1

Code variation 2 of 2Specific to an individual platform

Tap on a block to expand it, and tap it again to revert.

Cassette, Electron
Docked, 6502SP, Master
 LDA INWK,X             \ Copy the X-th byte of INWK to the X-th byte of NA%
 STA NA%,X
 LDA INWK+5,X           \ Copy the X-th byte of INWK+5 to the X-th byte of NA%
 STA NA%,X

 DEX                    \ Decrement the loop counter

 BPL GTL1               \ Loop back until we have copied all 8 bytes

                        \ Fall through into TR1 to copy the name back from NA%
                        \ to INWK. This isn't necessary as the name is already
                        \ there, but it does save one byte, as we don't need an
                        \ RTS here