Enhanced Joystick ports - mega STE

[Xebec]

Are there any mods available that allow you to add the enhanced joystick ports to a Mega STE?

[ParanoidLittleMan]

That will not work, because port for enhanced joysticks (I/O address) is used for DIP switch (settings) reading. I found it while digged in TOS 2.06 looking for HD floppy mode setting.

[Cyprian]

exactly,

TT/MSTE DIP switches uses Extended Joystick port hardware address: byte $FFFF9200

More here: http://www.atari-forum.com/viewtopic.php?t=28953

[Lynxpro]

So you're saying a VME expansion card couldn't be used to add the Enhanced Joystick Ports to a Mega STe or TT?

[ParanoidLittleMan]

This is not what we said. But, since that I/O address is used for some another function, you can not solve it so, that will be compatible with SW - games.

Only way is to remap port for DIP switch read (what means + HW logic, not something complicated and expensive), then Enhanced joystick port will be free. Of course, it needs mods in TOS too .

[Xebec]

Continuing the thread -  as an electronics n00b -

 

Does the VME bus on the Mega STE already have access to what it needs to access the ports/registers/"etc stuff" it needs if someone built a the enhanced ports into a VME card?

 

Would desoldering the dipswitches and patching TOS just for the HD floppy (dip switch 7) be enough?  (i.e. just force HD floppy on or off with the right ROM) -- the other thread seems to indicate that's the only actual use of the dip switches relative to TOS.   (No hardware changes).  

[ParanoidLittleMan]

VME bus has own address space. I know that IDE adapter via VME worked not without adding extra address logic for IDE port. So, most likely enhanced joystick port is not accessible there too.

Whole thing seems too complicated. And will need to add more than just connectors for the port self - there are 6 chips and lot of resistors in STE at those connectors . 

I guess that getting STE will be better solution, especially for someone inexperienced with electronic.

[Cyprian]

as @ParanoidLittleMan mentioned, VMA has its own address space. Enhanced Joystick ports through VME will be visible in Mega STE VME address space: $A00000 - $DFFFFF  ( ftp://retronn.de/docs/atari/VME_Spec_7-19-1991.pdf )

 

The problem is that appropriate software (like games) are expecting Enhanced Joystick under their own address space: $FF9200 - $FF9222

 

ST/TT address map:

http://cd.textfiles.com/ataricompendium/BOOK/PDF/APPENDB.PDF

ftp://ftp.lip6.fr/pub/atari/Docs/hardware.txt

 

Edited October 14, 2019 by Cyprian_K
additional link

[Lynxpro]

13 hours ago, Cyprian_K said:

as @ParanoidLittleMan mentioned, VMA has its own address space. Enhanced Joystick ports through VME will be visible in Mega STE VME address space: $A00000 - $DFFFFF  ( ftp://retronn.de/docs/atari/VME_Spec_7-19-1991.pdf )

 

The problem is that appropriate software (like games) are expecting Enhanced Joystick under their own address space: $FF9200 - $FF9222

 

ST/TT address map:

http://cd.textfiles.com/ataricompendium/BOOK/PDF/APPENDB.PDF

ftp://ftp.lip6.fr/pub/atari/Docs/hardware.txt

 

That's good to know. If only there was more ST games patched to use the Enhanced Joystick Ports that would have to be further modded to detect these addresses... 

 

What about the regular Mega ST and its expansion slot?

[Cyprian]

Mega ST has MegaBus expansion port. If I'm not wrong it has almost plain CPU pinout. Therefore should be possible to map additional hardware to any available address. E.g. new enhanced joysticks to $FF9200 - $FF9222