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NFG Forums => SIG X68000 => Topic started by: Psygnosis8 on October 25, 2016, 01:43:41 AM

Title: Removing internal RAM expansion Module?
Post by: Psygnosis8 on October 25, 2016, 01:43:41 AM
Hey, experts!

I've got an XVI Compact that someone put an internal RAM expansion into, but it turns out my external card has more. A number of games aren't booting because of this, so I'd like to remove the internal expansion and put the other one in the external slot.

I've been scanning the Wiki and I'm not seeing anything about where internal memory modules are located/how to remove them.  Anybody have a reference to pics/etc.

Thanks again!
Title: Re: Removing internal RAM expansion Module?
Post by: kamiboy on October 25, 2016, 02:09:34 AM
It plugs into a slot on the board if memory serves me right. Should be easy to spot once you pop that baby open. You can find pictures of the memory expansion boards online.
Title: Re: Removing internal RAM expansion Module?
Post by: neko68k on October 25, 2016, 03:23:01 AM
Internal RAM should be left there. Slot RAM is supplementary to this. Is your slot RAM card set up correctly. Dip switches and all that?
Title: Re: Removing internal RAM expansion Module?
Post by: Psygnosis8 on October 25, 2016, 04:06:20 AM
There are no dip switches.  It's got 10 Megs and a math co processor.  I can look up which module it is when I get home.

I assumed the lhes errors I get when I try to boot bigger/more complex games was due to not enough memory.  Maybe it's another reason?  Clearing the sram doesn't seem to help.
Title: Re: Removing internal RAM expansion Module?
Post by: Psygnosis8 on October 25, 2016, 11:51:26 AM
Okay...the model of external RAM board I have is a KGB-PRK II from BASIC House.  It doesn't have dip switches but it has jumpers.

This one is not listed in the Wiki.  Anyone have any idea how to get it properly configured?

Edit:

Ahhh, found it:
http://gamesx.com/wiki/doku.php?id=x68000:kgb-prkii_-_fpu_memory_board

Since I'm putting it in a new machine, does anyone know how to configure it?
Title: Re: Removing internal RAM expansion Module?
Post by: neko68k on October 26, 2016, 08:20:06 AM
I tweeted, got nothing. There's another thread here where the guy just tried different combinations of jumpers. I don't have a link handy.
Title: Re: Removing internal RAM expansion Module?
Post by: Psygnosis8 on October 27, 2016, 12:40:56 AM
Hey, thanks!  I was thinking of trying that.  There's 5 jumpers which means a gazillion permutations, but I'll try and mess around with it when I get a minute.
Title: Re: Removing internal RAM expansion Module?
Post by: neko68k on October 27, 2016, 01:42:30 AM
I can say it probably controls where the RAM sits in address space and that your goal is to get it to not overlap the internal RAM and to not leave any gaps in address space. Since its all just discrete logic on the board you could probably figure out what they do by following the traces and working out whats happening to the logic.
Title: Re: Removing internal RAM expansion Module?
Post by: corpsicle on October 27, 2016, 01:46:18 AM
How much is on the internal expansion?
Did you set the ram amount with switch?
Also AFAIK some of the expansion-bay ram expansions cant handle 16mhz.
Title: Re: Removing internal RAM expansion Module?
Post by: Psygnosis8 on October 29, 2016, 12:50:55 AM
It's an 8mb expansion.  I set Switch.x to 12mb because that's the max it can do.  I guess it's a guessing game with the jumpers.  Everything works okay when I remove it, except Valis II (LHES error--which is why I was trying to install the expansion ;) )
Title: Re: Removing internal RAM expansion Module?
Post by: neko68k on October 29, 2016, 01:03:51 PM
Switch should be set to what you have. It doesn't auto detect your max or anything.  That being said, make sure you let us know if you figure it out and we'll add it to the wiki page ☺
Title: Re: Removing internal RAM expansion Module?
Post by: Psygnosis8 on November 02, 2016, 01:15:14 PM
Will do.  I haven't had much luck yet but when I have some time I'll give it a go.