Re: IIGS CPU: How can ROM version be identified?

[dockery@griffin.cuc.ab.ca (Sean Dockery)]

sebugg@presby.edu wrote the following article:

|         IDENTIFYING WHICH ROM VERSION ON IIGS?
|         =====================================
| 
|        I am unable to identify the ROM version (00, 01, 03) of a IIgs
| cpu.   Any advice on how to do this?  There is no indication on any of
| the screens or on the control panel.   Is there a ROM identifier
| address as there is on the IIc?

You could look at the boot screen.  It will identify itself if it is a ROM
01 or ROM 03; it no identity, then it is a ROM 00.

For completeness, there is also the non-interactive way of doing it from
6502 (65816) assembly:

---------------------------------------------------------------------------
	ORG	$0300

ROMID	DW	$FFFF

* Confirm that this is a IIGS to begin with.  Exit early, if not.

IDIIGS	SEC
	JSR	$FE1F
	BCS	:EXIT

* Enable native mode, save previous mode state, enable 16 bit registers.
	
	CLC
	DFB	$FB	;XCE
	PHP
	DFB	$C3,$30	;REP $30

* Call IDROUTINE ($FE1F).  Y register has ROM version information.

	JSR	$FE1F
	STY	ROMID	;16-bit STY!

* Restore previous mode and register sizes.

	PLP
	DFB	$FB	;XCE

* If ROM 01 or ROM 03, we're done.

	LDA	ROMID
	BNE	:EXIT

* It is a ROM 00.  Check if faulty, exit if not.

	LDA	ROMID+1
	BNE	:EXIT

* ROMID will be set to $7F if faulty ROM 00.

	LDA	#$7F
	STA	ROMID

:EXIT	RTS
---------------------------------------------------------------------------

or, in Applesoft BASIC:

---------------------------------------------------------------------------
10  FOR I = 768 TO 768 + 35 : READ A: POKE I, A: NEXT I
20  CALL 770: ID = PEEK (768)
30  IF ID = 127 PRINT "BAD ROM 00" : END
40  PRINT "ROM 0";ID : END
50  DATA 255, 255,  56,  76,  31, 254, 176,  28
60  DATA  24, 251,  40, 195,  48,  76,  31, 254
70  DATA 140,   0,   3,  40, 173,   0,   3, 208
80  DATA  11, 173,   1,   3, 208,   6, 169, 127
90  DATA 141,   0,   3,  96
---------------------------------------------------------------------------

The Applesoft BASIC program was hand assembled (ie: the numbers in the DATA
statements are subject to human error.)

|        In the event that I have a Rom 00 version, is the free ROM upgrade
| deal still available from Apple?  If so, how do I request it?  (I have
| much experience getting IIc computers upgraded.)

Can't help you there.

| Stephen Buggie               sebugg@presby.edu         7/25/94
-- 
Sean Dockery                        |  Tickle us, do we not laugh?
Griffin Software Development Group  |  Prick us, do we not bleed?
dockery@griffin.cuc.ab.ca           |  Wrong us, shall we not revenge?