CT63 only starts from 030 mode

[foft]

I just got a new CT63 installed on my Falcon. I’ve been trying to debug a little with help from Centurion and on Atari-forum, but thought exxos is the ‘place to be’ for this kind of issue! https://www.atari-forum.com/viewtopic.p ... &start=275

The Falcon is fairly stock except:
I) it’s installed in a space case so has midi port extensions and a keyboard adaptor.
ii) Has a basic 74 series piggyback clock patch.
iii) Has an FPU fitted.
iv) Has the nvram battery replaced.

It’s the machine I’ve tried dfb1 on, which is working fine.

Symptoms:
CT63 030 mode works
CT63 060 mode ‘no sync’

Known problems:
I bought CL3 rather than CL2 pc133 ram

What I’ve found:
It appeared to boot sometimes. After some time I realised that it boots when I start in 030 mode, remove the jumper then press reset.

What I’ve tried:
Nano psu (itx085 from Cheiftec) and Full size ATX psu from my pc (Medion pc, not the best quality)
Replaced C7 with a 47uF cap
Removed ram. There is a no ram screen but this also only appears after starting first in 030 mode.

Tonight I’m going to try it my other falcon (with CT1 evolution 3b) to see if that works.

Any other ideas appreciated. Centurion suggested cleaning the extension pins, other than that I’m not sure what to check. I have a scope and logic analyser.

[exxos]

What speed are you trying to run the thing at in 060 mode ? I would always drop to 50MHz for initial testing.

[foft]

It’s running at 66MHz. I forgot to mention it has an on-board CTCM which allows 66MHz to 110MHz. So I don’t think I can set 50MHz. Though it has some kind of half clock speed jumper, not sure what that actually does.

[exxos]

Though it has some kind of half clock speed jumper, not sure what that actually does.

It does exactly that half the clock speed. So if you set 66Mhz in the control panel it will actually run at 33Mhz.

But like you say I would try it in a different Falcon first anyway.

[foft]

I just tried it on the other falcon.

This is a desktop falcon with a Centurbo 1 evolution 3b in and an FPU. It doesn't have the C7 capacitor fix.

This one seems to have the same issue, except slightly worse! It will not boot into 030 or 060 mode if I start it with the bus speeder off. To get it into 030 mode I can start it with the bus speeder on, then switch it off. After which I can then remove the 030/060 jumper to enable the 060 and reset to get the 060 to boot!

Once either machine is in a 'working state' I can reset it and it boots back up into 060 mode just fine.

Edit: Added C7 to this falcon, no change. For good measure I also tried another 68060, no change.

[Steve]

The creator of the ct63 is very specific on his original website that the memory has to be ... I'm guessing from my memory? CL2 high density? Please check yourself to be certain. I do not understand why you would try *anything* else till you have the correct memory.

[foft]

The creator of the ct63 is very specific on his original website that the memory has to be ... I'm guessing from my memory? CL2 high density? Please check yourself to be certain. I do not understand why you would try *anything* else till you have the correct memory.

I thought this myself, then Centurion told me that it also pops up a memory error screen with no memory installed. This does the same thing, it only works after starting in 030 mode.

[mikro]

It will not boot into 030 or 060 mode if I start it with the bus speeder off. To get it into 030 mode I can start it with the bus speeder on, then switch it off. After which I can then remove the 030/060 jumper to enable the 060 and reset to get the 060 to boot!

Definitely smells like a clock patch issue.

[foft]

The 'Space Case' Falcon that I'd like to install it in (without the CT1) has this installed:

clock_patch.JPG (183.51 KiB) Viewed 7646 times

I read that maybe I should remove the clock patch, but won't that break 030 mode? Or does it somehow work around this? Would I be best to remove it and install the exxos patch?

This is the screen with no ram, which I can only get to if I boot in 030 mode then remove jumper and reset. With ram installed I can get to the desktop with this process repeatedly, but to exclude the CL3 ram.

The_happy_no_ram_screen.JPG (79.1 KiB) Viewed 7646 times

[foft]

One silly thought... I haven't powered the floppy. CT60 TOS doesn't wait for it, while built in TOS doesn't?