Mega STe DIP switch #8 (DMA sound)?

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Pacman
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Mega STe DIP switch #8 (DMA sound)?

Post by Pacman » Thu Sep 21, 2017 10:47 am

I'm in the process of repairing my Mega STe and one of the problems I've been having is "Stereo sound is not available" whenever I try to open the "Sound" CPX module.
I'm pretty sure I had DIP switch #8 turned ON to allow stereo sound, but I found the opposite to be true now! Unfortunately there's not much information to be found on this online, and none of Atari's own documentation or service notes appear to mention it either.
Have I misunderstood, and the correct setting for DIP #8 should be OFF? Or could there be another reason why it's the opposite?
megaste_DIP8.png
megaste_DIP8.png (196.96 KiB) Viewed 504 times
Come to think of it, in the STe there's a similar row of jumper pads (instead of a DIP switch block) but I've only had to enable one of them, and that was for allowing HD (1.44MB) floppy disk formatting from the TOS 2.06 desktop. Maybe I've just misunderstood and DIP #8 on the Mega STe is for "Disable DMA sound", which means that it's turned OFF when the switch is turned ON...?
Mega STe | MonSTer with dual IDE-CF memory card adapter | STe | SM-144 |NEC Multisync 1990SXi | IDE doubler | ST_ESSC | RSVE | ICD Link II | Link '97 | HD floppy drive/AJAX | HD floppy module | Minolta PCMCIA card-drive | Realtime Clock module | Discovery cartridge | Unitor-2 | Export | Combiner | Steady Eye | Human Touch | Unicorn USB

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Re: Mega STe DIP switch #8 (DMA sound)?

Post by exxos » Thu Sep 21, 2017 12:12 pm

Try moving switch #7 up.
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Re: Mega STe DIP switch #8 (DMA sound)?

Post by Pacman » Thu Sep 21, 2017 12:26 pm

It's already up (on) and enables HD floppy formatting in TOS. If I turn it off then reboot I no longer get the "High density" TOS desktop formatting option.

I've checked the electrical connection of switch #8 and it's fine. I figure I must have been told/read that switch #8 handles DMA sound, so I assumed I had to enable it in order to get DMA sound. I always thought I had #8 turned on as well, but I must have remembered it incorrrectly.
Mega STe | MonSTer with dual IDE-CF memory card adapter | STe | SM-144 |NEC Multisync 1990SXi | IDE doubler | ST_ESSC | RSVE | ICD Link II | Link '97 | HD floppy drive/AJAX | HD floppy module | Minolta PCMCIA card-drive | Realtime Clock module | Discovery cartridge | Unitor-2 | Export | Combiner | Steady Eye | Human Touch | Unicorn USB

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Re: Mega STe DIP switch #8 (DMA sound)?

Post by exxos » Thu Sep 21, 2017 12:55 pm

What does sysinfo say ?

I did spot this post on Atari Age about similar issues...

http://atariage.com/forums/topic/245167 ... nd-no-dma/
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
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Re: Mega STe DIP switch #8 (DMA sound)?

Post by Pacman » Thu Sep 21, 2017 2:06 pm

Sysinfo says that DMA sound is ON when DIP #8 is OFF and OFF when DIP#8 is ON.
So my theory about hearing from somewhere that DIP #8 concerns audio but not not getting the facts right about the switch position seems to be the explanation.

Thanks for the link. I found it earlier on as well, but although it discusses these issues and someone fiddled with DIP #8 and got it working it doesn't specifically say in which position the switch should be in order to enable DMA audio. Oh well, I'll just leave it in the OFF position since that's what gives me DMA audio ;)
Mega STe | MonSTer with dual IDE-CF memory card adapter | STe | SM-144 |NEC Multisync 1990SXi | IDE doubler | ST_ESSC | RSVE | ICD Link II | Link '97 | HD floppy drive/AJAX | HD floppy module | Minolta PCMCIA card-drive | Realtime Clock module | Discovery cartridge | Unitor-2 | Export | Combiner | Steady Eye | Human Touch | Unicorn USB

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Re: Mega STe DIP switch #8 (DMA sound)?

Post by exxos » Thu Sep 21, 2017 2:11 pm

So just confirm, leaving dip switch #8 OFF, enables the DMA audio ?

And for future reference dip switch #7 ON, enables 1.44 floppy mode ?
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

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Re: Mega STe DIP switch #8 (DMA sound)?

Post by Pacman » Thu Sep 21, 2017 2:32 pm

Correct.
Mega STe | MonSTer with dual IDE-CF memory card adapter | STe | SM-144 |NEC Multisync 1990SXi | IDE doubler | ST_ESSC | RSVE | ICD Link II | Link '97 | HD floppy drive/AJAX | HD floppy module | Minolta PCMCIA card-drive | Realtime Clock module | Discovery cartridge | Unitor-2 | Export | Combiner | Steady Eye | Human Touch | Unicorn USB

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