exxos's Atari, Amiga & retro forum

Okay, interesting thing... I got a working FPU (68882) from a friend, I've plugged it in the socket and suddenly the TT starts to boot - I can see the Atari logo, memory test.... Then it waits for a long time and ends with 2 bombs, but I'm still missing the DCU (UA01) on motherboard and no floppy or hard drive is connected.

I didn't expect the FPU to be required in TT to boot.

Wow you're getting close now!!! :)

I can't remember if TOS 3.06 bombs without a floppy or not. If you have one laying about you could pop one on I imagine.

TOS 2.x and 3.x needs floppy drive

Cyprian wrote: 08 Jul 2021 17:54 TOS 2.x and 3.x needs floppy drive

TOS 2.06 does. TOS 3.06 doesn't. Proof: My TT with Atari TOS 3.06 booted to the Desktop without any drives whatsoever:

ok, good to know

jookie wrote: 08 Jul 2021 15:36 I didn't expect the FPU to be required in TT to boot.

As the TT was never sold without FPU, the TOS 3 developers did not bother checking for the FPU before using it.

That's even more interesting trivia, thanks czietz.

czietz wrote: 08 Jul 2021 18:22 As the TT was never sold without FPU, the TOS 3 developers did not bother checking for the FPU before using it.

Okay, nice to know... This one seems to be sorted out by plugging in the new FPU.

czietz wrote: 08 Jul 2021 18:08TOS 3.06 doesn't. Proof: My TT with Atari TOS 3.06 booted to the Desktop without any drives whatsoever:

So I'll got some other problem, which won't be fixed just by plugging in the floppy...

jookie wrote: 09 Jul 2021 07:53 So I'll got some other problem, which won't be fixed just by plugging in the floppy...

I did not test this on my TT, but I find it plausible that a missing SCSI DCU might cause a bus error while TOS is trying to boot from SCSI.