Sometimes I get 2 bombs!

[Higgy]

Hi,

I did a dirty thing and bought an ST FM 512kb

Of course when I tested it before I handed over my money it seemed fine, but now sometimes it shows 2 bombs.
I have removed the 4 socketed chips (2 TOS, GLU and MMU?) and reseated but no change.
I need to see if it is time related and it gives no bombs for a while.
How long should it take GEM/TOS to appear without a disk in and on fresh power up? Reset circuit issues?
I will get a motherboard pic posted later today. No patch wires I could see.

Cheers.

[stween]

How long should it take GEM/TOS to appear without a disk in and on fresh power up?

20-30 seconds? You should see the drive access light lit up, and you should hear the drive trying to do something.

[rubber_jonnie]

I've had machines take easily a minute to boot to desktop, the simplest solution is to pop a blank formatted disk in the drive.

[Steve]

Two bombs means 'drive not ready' - so you may have a floppy drive problem (which could be many different things)
I think I'd approach it this way:
1st - Are you even wanting a physical drive, if you're thinking of getting a Gotek drive then that may solve all your problems straight away
2nd - If you want the real drive, then you gotta service the drive. Clean the heads, replace drive capacitors.
- then, depending on what route you go, test the machine and see how you go. If you still have problems there is more you can do.

[Higgy]

Thanks guys.

From what you say and it's behaviour, I would say it is disk drive related.
It came with loads of disks, many mouldy.
I am not one for magnetic media and have a spare Gotek. Just printing the Atari ST mount now.

@Steve I have quite a few PC disk drives, are they a direct swap? If so I might give it a try just to test disks. Otherwise I will just download images of the disks for the Gotek USB.

[stween]

If you disconnect the drive (and leave it disconnected), the system should get to the desktop almost immediately. You won't have any drive icons on the desktop, but you'll get a desktop.

[exxos]

From what you say and it's behaviour, I would say it is disk drive related.
It came with loads of disks, many mouldy.

That is likely your problem then. The drive heads probably need cleaning at least. I would do that first and then try formatting a floppy and see what happens. Is not going to make much difference if you change the drive if all your floppies are bad.

But also note these machines need servicing and many fixes doing to become liable these days. We have a whole section on such things.

[Steve]

Unless you're an archivist or someone with a massive collection of floppies IMO it just isn't worth it. Just get a Gotek (I use flash floppy with OLED in all my machines) then you can load whatever you wish. You can also make your own disk images in Hatari and then use them on your ST.

And no PC drives aren't compatible unless they're a Sony and have been modded.

[Higgy]

Printed off the Gotek mount and have a Gotek on order (removed disk drive is a Sony something, can't remember model number now)

Working my way through the mandatory fixes.

On the Reset fix, where are the corresponding C100 and C102 on a C070789 Rev D?

For the Bus Resistors I measured 2 at 3.6K ohms and the other 3 at about 1.2K ohms.