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Re: Atari Mega ST 1 Rev 1 no boot
Posted: 28 Feb 2025 09:38
by rubber_jonnie
Dwh18 wrote: 28 Feb 2025 09:32
rubber_jonnie wrote: 27 Feb 2025 11:41
Definitely looking like a RAM issue. I'd definitely recommend using a serial cable, it will tell you an awful lot about the RAM during boot.
One thing I would add here is that the Mega ST mainboards are pretty fragile, so handle with care, I had one board where I plugged an IDE adapter into the MegaBus connector and it popped 2 vias and broke it.
Quick question.... serial output only works with Diag cart on right? or a regular boot should show some output?
Just with the diag cart.
Re: Atari Mega ST 1 Rev 1 no boot
Posted: 07 Mar 2025 10:31
by Dwh18
Hi
Not great output... get some artifacts in some tests but nothing special....One symptom I notice with the diag cart is that main menu takes ages to load
WhatsApp Image 2025-03-07 at 10.29.07_2cde6525.jpg
Re: Atari Mega ST 1 Rev 1 no boot
Posted: 07 Mar 2025 10:37
by HigashiJun
Is everything correctly set ?
Re: Atari Mega ST 1 Rev 1 no boot
Posted: 07 Mar 2025 10:50
by Dwh18
HigashiJun wrote: 07 Mar 2025 10:37
Is everything correctly set ?
I'm using 9600, N,1, and tried several control types ... HW, None, XonXoff
Any clue why Diag menu loads sooo slowwwww?
Re: Atari Mega ST 1 Rev 1 no boot
Posted: 07 Mar 2025 11:09
by HigashiJun
@Dwh18
I use Putty with an USB to RS232 cable, with the following settings:
Baud rate to 9600 , 8 data bits, no parity, 1 stop bit and no flow control.
Re: Atari Mega ST 1 Rev 1 no boot
Posted: 07 Mar 2025 11:23
by Dwh18
HigashiJun wrote: 07 Mar 2025 11:09
@Dwh18
I use Putty with an USB to RS232 cable, with the following settings:
Baud rate to 9600 , 8 data bits, no parity, 1 stop bit and no flow control.
With an adapter to convert DB9 to DB25?
Re: Atari Mega ST 1 Rev 1 no boot
Posted: 07 Mar 2025 11:46
by Badwolf
Dwh18 wrote: 07 Mar 2025 10:50
Any clue why Diag menu loads sooo slowwwww?
Lots of errors?
It looks like you're getting a full character set dump (in ascending order) on your terminal so something's happening.
BW
(BTW, a floating [or toggling] HALT or BR line could produce slow motion output)
Re: Atari Mega ST 1 Rev 1 no boot
Posted: 07 Mar 2025 11:54
by HigashiJun
Dwh18 wrote: 07 Mar 2025 11:23
With an adapter to convert DB9 to DB25?
No, there is no adapter.
The USB plugs directly into my USB port and the DB25 into the ATARI.
Re: Atari Mega ST 1 Rev 1 no boot
Posted: 07 Mar 2025 11:59
by rubber_jonnie
HigashiJun wrote: 07 Mar 2025 11:09
@Dwh18
Baud rate to 9600 , 8 data bits, no parity, 1 stop bit and no flow control.
These settings are indeed correct.
You should see data on screen as the machine boots and you will eventually get a menu over the terminal that shows the same thing as on the computer screen.
Did you revert the RAM upgrade fully as yet?
Re: Atari Mega ST 1 Rev 1 no boot
Posted: 07 Mar 2025 12:20
by Dwh18
Yes, all reverted ... but no onscreen duplicated on serial for sure