apple Lisa2. One working!! - one to go?
terry at webweavers.co.nz
Sat Dec 11 13:31:04 CST 2010
Thanks for commenting,
> But if you had a working IIGS would you sacrifice its IWM? :-)
Of course you wouldn't (-: Luckily places like arcadecomponents.com do have
such things for sale. Unfortunately they don't have Lisa ROMS
> I know you've said you're sure the I/O ROM says E8, does the sticker on
> the I/O board confirm this? It's very suspect to me.
No I corrected myself in a later post. It's actually H/EA which is maybe
even wierder! Consider I'm in New Zealand though, and I've noticed
sometimes our components can be slightly different (maybe due to 240v?).
> Also can you confirm that the floppy drive in that Lisa is a standard
> sony 400K one? If you take it apart, do you see only one head, and the
> top part of the clamp has a bit of foam?
Yes, it's definitely 400k.
> If that ROM is ok, it might well be the 800K ROM from SunRem. I'm
> guessing that it's either that, or it's corrupt.
Well, it could be either of those I guess, but it definitely is an Apple
ROM. I've searched hard but haven't found what version the 800k ROM uses.
Did Apple themselves ever bring a 800k one out?
> If either of those
> cases is wrong, well, you might have a new ROM that wasn't unreleased.
> Again, you're getting error 57, which is a timeout of the controller's
> self test, or a bus error during an attempt to access the controller.
> This has nothing to do with access to the floppy drive, but everything
> to do with the power on self test that 68000 does to check the 6504 is
Yes, that's what I suspected.
> Unless the IWM caused the 6504 to crash, it shouldn't cause a bus error
> or timeout when the 68000 tries to get status from the 6504. If on
> poweron the 6504 is fully functional, it does a self test also. Then,
> it writes the results into the shared floppy RAM, and the 68000 reads
> this status. Unfortunately, in all cases, you get the same error 57.
> It might be a timeout, bus error, or an internal 6504 failure, or a RAM
> The only clue we have is the oddball I/O ROM version. Please, check the
> sticker on the I/O ROM. If it says 88 on the label, either the EPROM
> went bad, or the I/O RAM is bad, or something went wrong that prevented
> the 6504 from reporting its version to the 68000. Does the sticker say
> E8 on it? Is there an Apple symbol on the sticker?
I'm sure it's a genuine Apple ROM. It has the same type of sticker than the
ROMS in the other machines (layout and font) and it's got a part number
341-0281-D plus a genuine Apple 84 trademark notice. I believe the usual
ROM is 314-0241-D. The H/EA is reported on the screen during the
self-tests. It's not on the sticker.
> Here's what the code looks like, all roads lead to 57 (EDISK)
> unfortunately, so we can't pinpoint exactly what went wrong. If you
> have a logic analyzer with the ability to analyze running 68000 code,
> and can catch the POST ROM going through this code, you might be able to
> see where it dies.
No I don't have one of those or indeed the knowledge to drive it.
> Perhaps if you can enter Service Mode, you could look at 02AE which is a
> copy of the result of the 6504's self test. If this is non-zero, it's
> what reported the error. 02A1 is a copy of the ROM version, which
> should contain E8.
No I can't enter the service mode. My keyboard (actually all three
keyboards) seem non-responsive in this respect.
>From what you've written Ray, I'm starting to think this repair might be a
bridge too far for me. I might have gone as far as I can. The options
might be to shelve it and wait until I can either source an IWM, a
replacement ROM, (or even a new board) from somewhere else. Not that they
come up that often (-: At least I have a Lisa 2 that at least tries to
access a disk so there is hope I can get one of these units fully working.
It would have been nice to have the one with the widget on-line though.
Anyway, the feedback is appreciated.
More information about the cctalk