Here are the features of the Open ROMs not found in the original ROMs from the 80s (many of them are configurable during compilation):

• improved keyboard scanning, resistant to ghosting and joystick interference, supports additional C128 keys

• joystick can be used to move text cursor

• pre-defined function keys

• JiffyDOS and DolphinDOS protocols support

• DOS wedge (direct mode only) - @<unit_number>, @<command>, @$[mask], @<unit_number>$, @<unit_number>$[mask] @

• BASIC extensions, see the documentation

• extended / tweaked LOAD / VERIFY commands

  • start/end addresses are displayed, in the Final cartridge style
  • command with just the file name tries to use the last device if it's number seems sane; otherwise uses 8
  • command without parameters tries to load first file from drive chosen as above

• LIST command should never damage the screen if trying to list memory content which is not a BASIC program

• high performance garbage collector

• turbo tape load support (as device 7, or using ←L / ←M, optionally with a file name), quite sophisticated: up to 250 blocks (can store bytes under I/O), on MEGA65 motherboard automatically adjusts itself for tape speed differences

• normal tape load error log is limited by free stack space only (no artificial limitation like in original ROMs)

• tape format autodetection; normal vs turbo is mostly transparent to user

• improved support for tape adapters (for using regular casette players and other audio devices instead of Datasette) and emulators

• built-in tape head align tool (only feasible to use on machines with extended memory, like MEGA65)

• uses RAM under ROM and I/O: 51199 bytes free (up to $CFFF) by default, but 61438 is also possible

• cold/warm start silences multiple SID chips

• warm start due to BRK prints out the instruction address

NOTE: extra features and their syntax can change in the future!

Features missing

The following ROM features are currently missing and are not planned due to space considerations:

• full tape support - VERIFY, SAVE, sequential files; tape is considered a legacy medium, so its support is going to be limited
• mock 6551 emulation - this only complicates the RS-232 support for original ROMs, probably noone needs it

The following ROM features are currently missing:

• most BASIC commands
• BASIC integer/float variables/arrays (strings work now, with the exception of undefined arrays)
• BASIC expression handling (again, strings should work now)
• RS-232 support
• NMI handling is incomplete

Hardware support status

Keyboard

Driver	Status	Remarks
C64	DONE
C128	DONE
MEGA65	PARTIAL	code mostly complete, but not tested yet

Screen

Driver	Status	Remarks
VIC-II	DONE
80 columns, VDC	NOT DONE
80 columns, MEGA65	PARTIAL	no windowing mode and C65/M65 extra keys support

Tape port (LOAD only!)

• Tapuino
• Datasette

Driver	Status	Remarks
normal	DONE	up to 202 blocks, like original ROM
turbo	DONE	up to 250 blocks, like the best implementations

IEC bus

• SD2IEC, petSD+, µIEC
• Pi1541, Ultimate II
• most disk drives and printers
• some hard drives

Driver	Status	Remarks
standard	DONE
JiffyDOS	PARTIAL	LOAD needs improvement for better performance
ELoad v1	NOT DONE
DolphinDOS	DONE
CIA burst mod	NOT DONE
MEGA65 burst	NOT DONE

IEEE-488 bus

• petSD+
• PET era disk drives and printers
• various scientific equipment

Driver	Status	Remarks
CBM cartridge	NOT DONE

MEGA65 storage

Driver	Status	Remarks
SD card	PARTIAL	work-in-progress, can already load files
floppy drive	NOT DONE
ram disk	NOT DONE

RS-232

• modems (telephone, WiFi)
• parallel port printers

Driver	Status	Remarks
UP2400	NOT DONE
UP9600	NOT DONE	work started, not functional yet
ACIA 6551	NOT DONE

API status

Status of the various APIs and variables from the original ROMs

Low memory locations (pages 0 - 3)

For the current status of the low memory location implementation andd usage check this file. NOTE: available vector to certain routine does not mean that this routine is fully implemented!

BASIC

Official BASIC routines

Entry	Unofficial	Name	Status	Remarks
(\$0003)		ADRAY1	NOT DONE
(\$0005)		ADRAY2	NOT DONE
(00300)	$E38B	ERROR	NOT DONE
(00302)	$A483	MAIN	NOT DONE	some implementation exists, but not connected here
(00304)	$A57C	CHRNCH	NOT DONE
(00306)	$A71A	QPLOP	NOT DONE	some implementation exists, but not connected here
(00308)	$A7E4	GONE	NOT DONE	some implementation exists, but not connected here
(0030A)	$AE86	EVAL	NOT DONE	some implementation exists, but not connected here
($A000)	$E394	cold start	PARTIAL
($A002)	$E3B7	warm start	PARTIAL

Math package

Floating point mathematical routines - not official, but well known and broadly used. Note: there is an awful mess regarding naming (sometimes same name references different routines in different sources), so a custom naming scheme was applied.

Address	Name	Status	Remarks
$A9C4	convert_FAC1_to_INT	NOT DONE
$AABC	print_FAC1	NOT DONE
$AF7B	compute_TI	NOT DONE
$AF7E	not named yet	NOT DONE
$AF87	set_FAC1_mantissa	DONE
$AF9A	compute_ST	DONE
$B1AA	FACINX	NOT DONE	convert FAC1 to 16-bit signed integer
$B1BF	convert_FAC1_to_s16	NOT DONE
$B391	GIVAYF	DONE	From the Microsoft BASIC, original name: GIVAYF
$B3A2	convert_Y_to_FAC1	DONE	From the Microsoft BASIC, original name: SNGFLT
$B794	convert_u8_A_to_FAC1	DONE
$B7B5	STRVAL	PARTIAL	Only for 38k memory model
$B7F7	convert_FAC1_to_ADDR	NOT DONE
$B849	add_HALF_FAC1	DONE	From the Microsoft BASIC, original name: FADDH
$B850	sub_MEM_FAC1	DONE	From the Microsoft BASIC, original name: FSUB
$B853	sub_FAC2_FAC1	DONE	From the Microsoft BASIC, original name: FSUBT
$B862	add_align_exponents	DONE	From the Microsoft BASIC, original name: FADD5
$B867	add_MEM_FAC1	DONE	From the Microsoft BASIC, original name: FADD
$B86A	add_FAC2_FAC1	DONE	From the Microsoft BASIC, original name: FADDT
$B8D2	abs_and_normal_FAC	DONE	From the Microsoft BASIC, original name: FADFLT
$B8D7	normal_FAC1	DONE	From the Microsoft BASIC, original name: NORMAL
$B8F7	zero_FAC1	DONE	From the Microsoft BASIC, original name: ZEROFC
$B8FE	add_mantissas_FAC1..	DONE	From the Microsoft BASIC, original name: FADD2
$B936	shift_carry_into_FAC	DONE	From the Microsoft BASIC, original name: SQUEEZ
$B947	inv_FAC1_mantissa	DONE	From the Microsoft BASIC, original name: NEGFAC
$B96F	inc_FAC1	DONE	From the Microsoft BASIC, original name: INCFAC
$B983	shiftr_FAC1	DONE	From the Microsoft BASIC, original name: SHIFTR
$B9EA	log_FAC1	DONE	From the Microsoft BASIC, original name: LOG
$BA28	mul_MEM_FAC1	DONE	From the Microsoft BASIC, original name: FMULT
$BA2B	mul_FAC2_FAC1	DONE	From the Microsoft BASIC, original name: FMULTT
$BA8C	mov_MEM_FAC2	DONE	From the Microsoft BASIC, original name: CONUPK
$BA90	get_FAC2_via_INDEX	DONE	From the Microsoft BASIC, no label
$BAE2	mul10_FAC1	DONE	From the Microsoft BASIC, original name: MUL10
$BAFE	div10_FAC1_p	DONE	From the Microsoft BASIC, original name: DIV10
$BB07	div_FAC2_MEM	DONE	From the Microsoft BASIC, original name: FDIVF
$BB0F	div_MEM_FAC1	DONE	From the Microsoft BASIC, original name: FDIV
$BB12	div_FAC2_FAC1	DONE	From the Microsoft BASIC, original name: FDIVT
$BB8F	mov_RES_FAC1	DONE	From the Microsoft BASIC, original name: MOVFR
$BBA2	mov_MEM_FAC1	DONE	From the Microsoft BASIC, original name: MOVFM
$BBA6	get_FAC1_via_INDEX	DONE	From the Microsoft BASIC, no label
$BBC7	mov_r_FAC1_TMP2	DONE	From the Microsoft BASIC, original name: MOV2F
$BBCA	mov_r_FAC1_TMP1	DONE	From the Microsoft BASIC, original name: MOV1F
$BBD0	mov_r_FAC1_VAR	DONE	From the Microsoft BASIC, original name: MOVVF
$BBD4	mov_r_FAC1_MEM	DONE	From the Microsoft BASIC, original name: MOVMF
$BBFC	mov_FAC2_FAC1	DONE	From the Microsoft BASIC, original name: MOVFA
$BC0C	mov_r_FAC1_FAC2	DONE	From the Microsoft BASIC, original name: MOVAF
$BC0F	mov_FAC1_FAC2	DONE	From the Microsoft BASIC, original name: MOVEF
$BC1B	round_FAC1	DONE	From the Microsoft BASIC, original name: ROUND
$BC2B	sgn_FAC1_A	DONE	From the Microsoft BASIC, original name: SIGN
$BC39	sgn_FAC1	DONE	From the Microsoft BASIC, original name: SGN
$BC3C	convert_A_to_FAC1	DONE	From the Microsoft BASIC, original name: FLOAT
$BC44	convert_i16_to_FAC1	DONE	From the Microsoft BASIC, original name: FLOATS
$BC58	abs_FAC1	DONE	From the Microsoft BASIC, original name: ABS
$BC5B	FCOMP	DONE	From the Microsoft BASIC, original name: FCOMP
$BC9B	QINT	DONE	From the Microsoft BASIC, original name: QINT
$BCCC	int_FAC1	DONE	From the Microsoft BASIC, original name: INT
$BCE9	clear_FAC1	DONE	From the Microsoft BASIC, original name: CLRFAC
$BCF3	FIN	PARTIAL	From the Microsoft BASIC Only for 38k memory model
$BD7E	FINLOG	DONE	From the Microsoft BASIC, original name: FINLOG
$BDDD	FOUT	DONE	From the Microsoft BASIC, original name: FOUT
$BF71	sqr_FAC1	DONE	From the Microsoft BASIC, original name: SQR
$BF74	sqr_FAC2	DONE	From the Microsoft BASIC, no label
$BF78	pwr_FAC2_MEM	DONE	From the Microsoft BASIC, no label
$BF7B	pwr_FAC2_FAC1	DONE	From the Microsoft BASIC, original name: FPWRT
$BFB4	toggle_sign_FAC1	DONE	From the Microsoft BASIC, original name: NEGOP
$BFED	exp_FAC1	PARTIAL	From the Microsoft BASIC Only for the 38k model
$E043	poly1_FAC1	DONE	From the Microsoft BASIC, original name: POLYX
$E059	poly2_FAC1	DONE	From the Microsoft BASIC, original name: POLY
$E097	rnd_FAC1	DONE
$E09A	rnd_A	DONE
$E0BE	rnd_generate	DONE
$E264	cos_FAC1	DONE	From the Microsoft BASIC, original name: COS
$E26B	sin_FAC1	DONE	From the Microsoft BASIC, original name: SIN
$E2B4	tan_FAC1	DONE	From the Microsoft BASIC, original name: TAN
$E30E	atn_FAC1	DONE	From the Microsoft BASIC, original name: ATN

In addition to the routines, the following floating-number constants are available at their original locations:

Address	Name	Status	Remarks
$AEA8	const_PI	DONE	π
$B1A5	const_NEG_32768	DONE	-32768
$B9BC	const_ONE	DONE	1.0
$B9D6	const_INV_SQR_2	DONE	1.0 / sqr(2.0)
$B9DB	const_SQR_2	DONE	sqr(2.0)
$B9E0	const_NEG_HALF	DONE	-0.5
$B9E5	const_LOG_2	DONE	log_e(2.0)
$BAF9	const_TEN	DONE	10.0
$BDB3	const_NZ0999	DONE	99999999.9
$BDB8	const_NZ9999	DONE	999999999.2
$BDBD	const_NZMIL	DONE	1000000000.0
$BF11	const_HALF	DONE	0.5
$BFBF	const_INV_LOG_2	DONE	1.0 / log_e(2.0)
$BFE8	const_ONE duplicate	DONE	1.0
$E2E0	const_HALF_PI	DONE	PI / 2.0
$E2E5	const_DOUBLE_PI	DONE	PI * 2.0
$E2EA	const_QUARTER	DONE	0.25
$E309	const_DOUBLE_PI duplicate	DONE	PI * 2.0

And the following big endian int32 constants at their original locations:

Address	Name	Status	Remarks
$BF16	FOUTBL	DONE	100000000
$BF1A	FOUTBL + 4	DONE	10000000
$BF1E	FOUTBL + 8	DONE	-1000000
$BF22	FOUTBL + 12	DONE	100000
$BF26	FOUTBL + 16	DONE	-10000
$BF2A	FOUTBL + 20	DONE	1000
$BF2E	FOUTBL + 24	DONE	-100
$BF32	FOUTBL + 28	DONE	10
$BF36	FOUTBL + 32	DONE	-1
$BF3A	FDCEND	DONE	-2160000
$BF3E	FDCEND + 4	DONE	216000
$BF42	FDCEND + 8	DONE	-36000
$BF46	FDCEND + 12	DONE	3600
$BF4A	FDCEND + 16	DONE	-600
$BF4E	FDCEND + 20	DONE	60

Other unofficial BASIC routines/locations

Not all of them - only these we want to have implemented.

Address	Name	Status	Remarks
$A004	revision str	DONE
$A408	REASON	NOT DONE
$A453	(unknown)	NOT DONE
$A533	LINKPRG	DONE
$A644	new	NOT DONE
$A659	set txt ptr	NOT DONE
$A68E	RUNC	DONE
$A7AE	NEWSTT	PARTIAL	redirected to RUN command
$AB1E	STROUT	DONE
$AD9E	FRMEVL	PARTIAL
$BDCD	LINPRT	DONE	temporary implementation
$E3A2	MOVCHG	DONE	memory model 38K only
$E3BF	INIT	NOT DONE
$E422	INITMSG	DONE
$E453	RVECT	NOT DONE

Kernal

Official Kernal routines

NOTE: Even the 'DONE' routines won't support features described as missing in one of the previous chapters!

Address	Unofficial	Name	Status	Remarks
(\$028F)		KEYLOG	DONE
$FF81	$FF5B	CINT	DONE
$FF84	$FDA3	IOINIT	DONE
$FF87	$FD50	RAMTAS	DONE
$FF8A	$FD15	RESTOR	DONE
$FF8D	$FD1A	VECTOR	DONE
$FF90		SETMSG	DONE
$FF93		SECOND	DONE
$FF96		TKSA	DONE
$FF99	$FE25	MEMTOP	DONE
$FF9C		MEMBOT	DONE
$FF9F		SCNKEY	DONE
$FFA2		SETTMO	DONE
$FFA5		ACPTR	DONE
$FFA8		CIOUT	DONE
$FFAB		UNTLK	DONE
$FFAE		UNLSN	DONE
$FFB1		LISTEN	DONE
$FFB4		TALK	DONE
$FFB7		READST	DONE
$FFBA		SETFLS	DONE
$FFBD		SETNAM	DONE
$FFC0	$F34A	OPEN	DONE
$FFC3	$F291	CLOSE	DONE
$FFC6	$F20E	CHKIN	DONE
$FFC9	$F250	CKOUT	DONE
$FFCC	$F333	CLRCHN	DONE
$FFCF	$F157	CHRIN	PARTIAL	no screen device support
$FFD2	$F1CA	CHROUT	DONE
$FFD5	$F49E	LOAD	DONE
(\$0330)	$F4A5	LOAD	DONE
$FFD8	$F5DD	SAVE	DONE
(\$0332)	$F5ED	SAVE	DONE
$FFDB		SETTIM	DONE
$FFDE		RDTIM	DONE
$FFE1	$F6ED	STOP	DONE
$FFE4	$F13E	GETIN	PARTIAL	no screen device support
$FFE7	$F32F	CLALL	DONE
$FFEA		UDTIM	DONE
$FFED		SCREEN	DONE
$FFF0	$E50A	PLOT	DONE
$FFF3		IOBASE	DONE
($FFFA)		NMI vec	PARTIAL
($FFFC)	$FCE2	RESET vec	DONE
($FFFE)		IRQ/BRK vec	DONE

Unofficial Kernal routines/locations

Not all of them - only these we want to have implemented.

Address	Name	Status	Remarks
$E518	legacy part of CINT	DONE
$E51B	init screen keyboard, no VIC	DONE
$E544	clear screen	DONE
$E50C	set cursor position	DONE
$E536	init screen ?	PARTIAL
$E566	home cursor	DONE
$E56C	set PNT and USER values	DONE
$E5A0	setup VIC II & I/O	DONE
$E6B6	advance cursor	NOT DONE
$E701	previous line	NOT DONE
$E716	screen CHROUT	NOT DONE
$E8DA	color code table	DONE
$E8EA	scroll logical line up	DONE
$E96C	insert line on top	NOT DONE
$E9FF	clear line	DONE
$EA31	default IRQ	PARTIAL
$EA7E	ack CIA1 + below	DONE
$EA81	ret from IRQ/NMI	DONE
$EB48	set keyboard mapping table	DONE
$F142	get key from buffer	DONE
$F3F6	(unknown)	NOT DONE
$F646	IEC close	NOT DONE
$FD30	default vectors	DONE
$FD90	(unknown)	NOT DONE
$FE2D	memtop set part	DONE
$FE47	default NMI	PARTIAL
$FE66	default BRK	DONE
$FF80	revision byte	DONE

API extensions - MEGA65 build

Note: this is likely to change in the future, possibly in an incompatible way!

Address	Name	Status	Remarks
?	MONITOR	WIP	launches a machine language monitor
?	BOOTCPM	WIP	launches the CP/M operating system
?	PRHEX	DONE	print hex value from .A
$FF7D	PRIMM	DONE	print immediate, address compatible with C128 and C65 ROMs
$FFF8		DONE	reset vector for usage within hypervisor, starts in legacy mode