constants.go

package main

/*
Memory map, pages:
	00: zero page
	01: stack
	02: mos vectors and other
	...
	80: loaded rom
	...
	fa: brk error messages
	fb: entrypoints trapped by the host
	fc: FRED
	fd: JIM
	fe: SHEILA
	ff: mos and 6502 entrypoints

*/
const (
	zpA            uint16 = 0x00ef
	zpX            uint16 = 0x00f0
	zpY            uint16 = 0x00f1
	zpStr          uint16 = 0x00f2 // OSCLI command line
	zpROMSelect    uint16 = 0x00f4
	zpAddress      uint16 = 0x00f6
	zpAccumulator  uint16 = 0x00fc
	zpErrorPointer uint16 = 0x00fd
	zpEscapeFlag   uint16 = 0x00ff

	vectorBRK           uint16 = 0x0202
	mosVariablesStart   uint16 = 0x0236
	mosRomTypeTable     uint16 = 0x023a
	mosSpoolFileHandle  uint16 = 0x0257
	mosCharDestinations uint16 = 0x027c
	mosCurrentLanguage  uint16 = 0x028c
	mosVariablesEnd     uint16 = 0x028f

	// ROM header https://tobylobster.github.io/mos/mos/S-s2.html#SP26
	userMemBottom             uint16 = 0x0e00
	romStartAddress           uint16 = 0x8000
	romEndAddress             uint16 = 0xbfff
	romServiceEntry           uint16 = 0x8003
	romTypeByte               uint16 = 0x8006
	romCopyrightOffsetPointer uint16 = 0x8007
	romVersion                uint16 = 0x8008
	romTitleString            uint16 = 0x8009

	// Support code on the firmware. Check firmware.lst when changing firmware.s
	procServiceRoms uint16 = 0xf000
	procOSBYTE_143  uint16 = 0xf015
	procGSINIT      uint16 = 0xf03b
	procGSREAD      uint16 = 0xf057

	// See http://beebwiki.mdfs.net/Service_calls
	//serviceNoOperation uint8 = 0
	serviceOSCLI  uint8 = 4
	serviceOSBYTE uint8 = 7
	serviceOSWORD uint8 = 8
	serviceHELP   uint8 = 9

	// Scratch area for errors in page 0xfa
	errorArea             uint16 = 0xfa00
	errorMessageMaxLength int    = 100
	errorTodo             uint8  = 129 // TODO: find proper error number

	// Entry points for host interception in page 0xfb
	entryPoints       uint16 = 0xfb00
	epUPT             uint16 = 0xfb00
	epEVNT            uint16 = 0xfb01
	epFSC             uint16 = 0xfb02
	epFIND            uint16 = 0xfb03
	epGBPB            uint16 = 0xfb04
	epBPUT            uint16 = 0xfb05
	epBGET            uint16 = 0xfb06
	epARGS            uint16 = 0xfb07
	epFILE            uint16 = 0xfb08
	epRDCH            uint16 = 0xfb09
	epWRCH            uint16 = 0xfb0a
	epWORD            uint16 = 0xfb0b
	epBYTE            uint16 = 0xfb0c
	epCLI             uint16 = 0xfb0d
	epIRQ2            uint16 = 0xfb0e
	epIRQ1            uint16 = 0xfb0f
	epBRK             uint16 = 0xfb10
	epUSER            uint16 = 0xfb11
	epSYSBRK          uint16 = 0xfb12
	epRDRM            uint16 = 0xfb13
	epVDUCH           uint16 = 0xfb14
	epGSINIT          uint16 = 0xfb15
	epGSREAD          uint16 = 0xfb16
	epNET             uint16 = 0xfb17
	epVDU             uint16 = 0xfb18
	epKEY             uint16 = 0xfb19
	epINS             uint16 = 0xfb1a
	epREM             uint16 = 0xfb1b
	epCNP             uint16 = 0xfb1c
	epIND1            uint16 = 0xfb1d
	epIND2            uint16 = 0xfb1e
	epIND3            uint16 = 0xfb1f
	epEntryPointsLast uint16 = 0xfb1f

	// Fred, Jim and Sheila
	sheilaStart    uint16 = 0xf000
	sheilaRomLatch uint16 = 0xfe30

	extentedVectorTableStart uint16 = 0xff00
	extentedVectorTableEnd   uint16 = 0xff51

	maxFiles          uint8 = 100
	maxFilenameLength int   = 255

	// Maximim delay to detect a double control C to quit
	controlCDelayToQuitMs = 500

	metadataExtension = ".inf"
)