Hello,

some time ago, I discovered my first software package which runs on any 68k
Mac, tested up to OS 9. But crashes on PPC.

I observed this on the SNA.ps application, as soon as I'm trying to connect
too a peer system. What is SNA.ps? See link below.

<https://try-as400.pocnet.net/wiki/Apple_SNA.ps>

Does any of you observe another software which reproducibly crashes only on
PPCs but not on 68k Macs? I found no difference on 68k between 24- and 32 bit
addressing mode. But I suddenly got the idea to probably retest with virtual
memory enabled.

--

:wq! PoC

Patrik Schindler wrote:

> any of you observe another software which reproducibly crashes
> only on PPCs but not on 68k Macs?

Yes, this will occur for any 68k encoded Mac software that requires
Floating Point Math, i.e.; an onboard FPU to be present. This is a 68k
FPU that's required, not a built-in PPC FPU.

PPC's 68k emulation does not emulate a 68k FPU, so any 68k software
requiring an FPU, will not run on that PPC Mac.

The workaround for this is a 3rd party FPU emulator, to enable those
68k programs to run on PPC hardware.

The best 68k FPU emulator solution for PPC Mac's is PowerFPU.
<http://macintoshgarden.org/apps/powerfpu>

Not saying this is the cause of your 68k program not working on PPC
hardware. Only, that it does occur for any 68k program that requires
floating point math.

Another cause of 68k software being unable to run on PPC Macintosh, is
any 68k software that requires the presence of a Memory Management Unit
(MMU). <https://en.wikipedia.org/wiki/Memory_management_unit>

PPC's 68k emulation does not emulate a 68k MMU either, and I don't know
of a 3rd party soulution to this one. It is however, rare for 68k
software to demand this. It happens, but it's rare.

--
dee

Mike Dee <mikedee@emteedee.invalid> wrote:

> Patrik Schindler wrote:
>
>> any of you observe another software which reproducibly crashes only on PPCs
>> but not on 68k Macs?
>
> Yes, this will occur for any 68k encoded Mac software that requires Floating
> Point Math, i.e.; an onboard FPU to be present. This is a 68k FPU that's
> required, not a built-in PPC FPU.

Ah, that's a good hint, thanks!

> Not saying this is the cause of your 68k program not working on PPC
> hardware. Only, that it does occur for any 68k program that requires
> floating point math.
>
> Another cause of 68k software being unable to run on PPC Macintosh, is any
> 68k software that requires the presence of a Memory Management Unit (MMU).
> <https://en.wikipedia.org/wiki/Memory_management_unit>

The system requirements according to the package are a Mac Plus and System
7.0. For the client, and that's what I'm talking about. That one has neither
an FPU, nor an MMU. But maybe the emulator code uses a gestalt call to know
what kind of machine it's running on, and dynamically branches to differently
optimized code? On the other hand, we're talking about a terminal emulator.

I dimly remember MacsBug stating an unimplemented instruction or trap which
supports your thinking. I'll try an 68k FPU emulator and check if this fixes
the error.

Again, thanks for the hint!

> PPC's 68k emulation does not emulate a 68k MMU either, and I don't know
> of a 3rd party soulution to this one. It is however, rare for 68k
> software to demand this. It happens, but it's rare.

I guess that the requirement for an MMU is more an OS thing. Maxima comes to
mind: A control panel extension to provide virtual memory when running System
6.

--

:wq! PoC

Patrik Schindler wrote:

> The system requirements according to the package are a Mac Plus
> and System 7.0. For the client, and that's what I'm talking about.
> That one has neither an FPU, nor an MMU. But maybe the emulator
> code uses a gestalt call to know what kind of machine it's running
> on, and dynamically branches to differently optimized code? On the
> other hand, we're talking about a terminal emulator.

The web link you provided in your OP, goes on to say, under System
Compatibility:
"The client crashes upon connecting via a SNA�ps gateway when ran on
PowerPC Macs,
[...]
The gateway software requires special hardware for the SNA network
connection and is therefore limited to NuBus systems. [...] Testing of
the gateway software on the first generation NuBus equipped PowerMacs
also hasn�t been done, yet."

And under Pitfalls:
"Neither SNA�ps 5250, nor SNA�ps print can be used on PowerPC machines
when connecting via a SNA�ps gateway. As soon as the connection is to
be set, the client crashes with an illegal instruction error."

I cannot imagine there are many Nubus slotted Macs that can run Mac OS
9. But, as the author also says, "untested".

It seems though that compatibility for running this software on PPC
Macintosh, if it is going to work, has very specific requirements.

So, good luck with your tests, I hope the FPU emulator is of use, not
only for this program, but for any others you might trial.

--
dee

Mike Dee <mikedee@emteedee.invalid> wrote:

> The web link you provided in your OP, goes on to say, under System
> Compatibility:
> "The client crashes upon connecting via a SNA?ps gateway when ran on
> PowerPC Macs,
> [...]

FYI, that's my Wiki and I have written that text myself. :-)

> The gateway software requires special hardware for the SNA network
> connection and is therefore limited to NuBus systems. [...] Testing of
> the gateway software on the first generation NuBus equipped PowerMacs
> also hasn?t been done, yet."

Yes. I think the text shows that there is a distinction between client and
server. The server (gateway) runs fine. I have not yet tested the gateway on a
NuBus PPC machine, because it runs good enough on the Quadra 700 I've picked
as gateway machine. NuBus is mandatory because my sole possibility for network
connection to AS/400 is the Token Ring Card as described in the article.

> And under Pitfalls:
> "Neither SNA?ps 5250, nor SNA?ps print can be used on PowerPC machines
> when connecting via a SNA?ps gateway. As soon as the connection is to
> be set, the client crashes with an illegal instruction error."
>
> I cannot imagine there are many Nubus slotted Macs that can run Mac OS
> 9. But, as the author also says, "untested".

Please don't confuse client (e. g. the 5250 terminal emulator) and gateway
software. The gateway is a protocol converter/encapsulator for the IBM SNA
protocol.

The gateway software needs "special" NuBus hardware as pointed out in the Wiki
article, and thus requires a Mac II class machine.

The client needs any Mac starting with a Mac Plus, and running System 7.

> It seems though that compatibility for running this software on PPC
> Macintosh, if it is going to work, has very specific requirements.

Which software? The gateway? Or the client?

> So, good luck with your tests, I hope the FPU emulator is of use, not
> only for this program, but for any others you might trial.

Thanks! As said, this is the first application I've encountered in years which
crashes on PPC but runs fine on the latest 68k hardware.

--

:wq! PoC

In article <lmlma3Fo2arU3@mid.individual.net>,
poc@pocnet.net (Patrik Schindler) wrote:

> Hello,
>
> some time ago, I discovered my first software package which runs on any 68k
> Mac, tested up to OS 9. But crashes on PPC.
>
> I observed this on the SNA.ps application, as soon as I'm trying to connect
> too a peer system. What is SNA.ps? See link below.
>
> <https://try-as400.pocnet.net/wiki/Apple_SNA.ps>
>
> Does any of you observe another software which reproducibly crashes only on
> PPCs but not on 68k Macs? I found no difference on 68k between 24- and 32 bit
> addressing mode. But I suddenly got the idea to probably retest with virtual
> memory enabled.

I remember the first time I ran into this was when I tried to run either Think C
5 or 6 on my Power Mac 8600. Very excited about the move up from coding on a
IIci and the resulting shorter compiling times, I hit the shortcuts for running
my code and ... a hard crash followed. Reboot, tried again and same result.

Given I had moved the code over from the IIci and *knew* it runs, it had to be a
Think C problem. Some online research later confirmed that.

In article <lmvp8sFb9b7U1@mid.individual.net>,
poc@pocnet.net (Patrik Schindler) wrote:

> Mike Dee <mikedee@emteedee.invalid> wrote:
>
> > The web link you provided in your OP, goes on to say, under System
> > Compatibility:
> > "The client crashes upon connecting via a SNA?ps gateway when ran on
> > PowerPC Macs,
> > [...]
>
> FYI, that's my Wiki and I have written that text myself. :-)
>
> > The gateway software requires special hardware for the SNA network
> > connection and is therefore limited to NuBus systems. [...] Testing of
> > the gateway software on the first generation NuBus equipped PowerMacs
> > also hasn?t been done, yet."
>
> Yes. I think the text shows that there is a distinction between client and
> server. The server (gateway) runs fine. I have not yet tested the gateway on a
> NuBus PPC machine, because it runs good enough on the Quadra 700 I've picked
> as gateway machine. NuBus is mandatory because my sole possibility for network
> connection to AS/400 is the Token Ring Card as described in the article.
>
> > And under Pitfalls:
> > "Neither SNA?ps 5250, nor SNA?ps print can be used on PowerPC machines
> > when connecting via a SNA?ps gateway. As soon as the connection is to
> > be set, the client crashes with an illegal instruction error."
> >
> > I cannot imagine there are many Nubus slotted Macs that can run Mac OS
> > 9. But, as the author also says, "untested".
>
> Please don't confuse client (e. g. the 5250 terminal emulator) and gateway
> software. The gateway is a protocol converter/encapsulator for the IBM SNA
> protocol.
>
> The gateway software needs "special" NuBus hardware as pointed out in the Wiki
> article, and thus requires a Mac II class machine.
>
> The client needs any Mac starting with a Mac Plus, and running System 7.
>
> > It seems though that compatibility for running this software on PPC
> > Macintosh, if it is going to work, has very specific requirements.
>
> Which software? The gateway? Or the client?
>
> > So, good luck with your tests, I hope the FPU emulator is of use, not
> > only for this program, but for any others you might trial.
>
> Thanks! As said, this is the first application I've encountered in years which
> crashes on PPC but runs fine on the latest 68k hardware.

Hi, Patrick.

I also have seen that sometimes. There was a version of Joshua Stein's
wonderful Wallops IRC client that worked on 68K, but crashed on my G3.

He immediately sent out an updated version which didn't crash, so he
might know what caused that crash.

Regards,
Rene