basic_editor/basiced.s65 at master · tom-seddon/basic_editor · GitHub

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                .include "submodules/beeb/include/beeb.s65"

;-------------------------------------------------------------------------

; Valid ROMs:

; BUILD_TYPE==0: BBC Micro

; BUILD_TYPE==1: BBC Micro HI

; BUILD_TYPE==2: BBC Master MOS 3.50 relocatable ($8000 version) (runs
; as-is, but only really makes sense in conjunction with a bit of DIY
; so that the MOS can find its relocation bitmap)

; BUILD_TYPE==8: Electron

; BUILD_TYPE==9: Electron HI (untested)

;-------------------------------------------------------------------------

; Not valid ROMs:

; BUILD_TYPE==3: BBC Master MOS 3.50 relocatable ($b800 version) (only
; used to generate the relocation bitmap)

; BUILD_TYPE==4: assembled at $3800 (useable for testing routines from
; BASIC in the host processor)

;-------------------------------------------------------------------------

HI_ADDRESS = $b800

                .if BUILD_TYPE==0

RELOCATABLE=false
HI=false
ELECTRON=false
SVC_BASE=$8000
LANG_BASE=$8000

                .elsif BUILD_TYPE==1

RELOCATABLE=false
HI=true
ELECTRON=false
SVC_BASE=$8000
LANG_BASE=HI_ADDRESS

                .elsif BUILD_TYPE==2

RELOCATABLE=true
HI=false
ELECTRON=false
SVC_BASE=$8000
LANG_BASE=$8000

                .elsif BUILD_TYPE==3

RELOCATABLE=true
HI=false
ELECTRON=false
SVC_BASE=$8000
LANG_BASE=HI_ADDRESS

                .elsif BUILD_TYPE==4

RELOCATABLE=false
HI=false
ELECTRON=false

; the ROM ought to fit (at least, in Mode 7...) starting from $3c00,
; but the TOC and/or extra debug junk might push the size past 16K.
SVC_BASE=$3800
LANG_BASE:= $3800

                .elsif BUILD_TYPE==8

RELOCATABLE=false
HI=false
ELECTRON=true
SVC_BASE=$8000
LANG_BASE=$8000

                .elsif BUILD_TYPE==9

RELOCATABLE=false
HI=true
ELECTRON=true
SVC_BASE=$8000
LANG_BASE=HI_ADDRESS

                .endif

;-------------------------------------------------------------------------

                .include "zp.s65"
                .include "workspace.s65"
                .include "cmds.s65"
                .include "shared_constants.s65"

                .include "mainpart.s65"

*=0
                .dsection zp

                ; Zero page unused by BASIC:

; 1/2 = $4f... - see BASIC ROM user guide

; 4 = $4c... - not quite clear? see http://8bs.com/basic/memory.htm

; 4.32 = $4f... - see https://github.com/hoglet67/BBCBasic4r32/blob/master/disassembly/Basic432.asm

; So $60 should be fairly safe...

*=$60
                .dsection basic_unused_zp

                ; language zero page runs up to $8f, but it would be
                ; nice to leave $70...$8f free as BASIC reserves that
                ; for user stuff. Then you can go BASIC->BE->BASIC
                ; safe in the knowledge that this region will be
                ; preserved.
                ;
                ; (if this error is ever hit, there are options...)
                .cerror *>=$70,"too much zero page use"

*=SVC_BASE
                .dsection service

                .logical LANG_BASE+*-SVC_BASE

                .dsection language

                .here