Jump to content
IGNORED

The FinalGROM 99


ralphb

Recommended Posts

The only thing limiting current to the sideport or cartridge port is the width of the copper along the way as far as I could tell.

 

I thought you needed an external power supply? Or was that only if you attached it to the right of the Speech Synth?

Link to comment
Share on other sites

I'm currently working on a "RAM mode" with RAM support (not GRAM!), and I'd like your feedback on this matter.

 

Right now I favor to have a ROM section from >6000 to >6FFF and a RAM section from >7000 to >7FFF. A bank switch is done by writing to >6xxx, while writing to >7xxx will update the RAM value. This is quite simple to implement. IIRC the Wiesbaden Supermodule did it like this, and it also looks like the MiniMem.

 

The ROM area could be reduced down to >6000->6100. This is the smallest area that needs to be reserved for bank switching to work. But having a smaller ROM area makes the internal logic mode complex, which is why I favor the 4K/4K variant.

 

Now the main question is: Should the RAM be shared by all banks, or does each bank have its own 4K of RAM? The first version is much simpler to program for, but it has only 4K of RAM instead of the 256K of the second version. Can some developers comment what they would prefer (other than "both" ;))?

 

Note that RAM mode will be a special mode that programs will have to choose; it's not the default for legacy programs. In other words, backward compatibility is not an issue here.

 

Besides accommodating the Mini Memory, you'll be creating "a new format" only supported by The FinalGROM 99. One that would probably soon be supported by the main emulators. Let's roughly describe the options as

 

1) 256K(4K) ROM and 4K RAM

 

or

 

2) 512K(4K ROM+4K RAM)

 

Remember, the 512K(8K ROM) option is already there. And this may default to case 2) !?!!

 

With case 1) you select a program from the FG99 menu, and I guess the 4K RAM could be preloaded from the first 8K chunk. All other banks would then deliver 4K ROM as not to overwrite the 4K RAM !?

 

With case 2) you, the laidback programmer, will miss the shared RAM - if you think "console only" and FG99. But then a lot of software, and also most newer software, expect to find the common 32K RAM Expansion. And these days the 32K doesn't have to come in a big box (CF7, nano, internal and the new one from jedimatt42). So there's almost no aesthetic arguments, - like opt out on everything but yet accept the FG99. But there's the arguments of beginners, money, wifes and more, - going for the FG99 and not getting around to the 32K.

 

Still with case 2) let's consider a game with 60 grand locations. All locations preloaded. All locations individually manipulated and sections put to the screen one way or another. RPG, space shooter, whatever, even consider Office stuff like word-processors, databases etc. keeping in mind that there's no 32K limit (but a 256K RAM limit) and no slow disk access. But then comes the question: - How do we save the 256K !? Or do the FG99 retain the 512K for the next powerup and how to select that ? Maybe you want to play another game and then go back to where you left off ...

 

Bottomline. As a programmer and looking to the future, I would like the non shared version - or could we have it all !?!?!!!?

 

;)

Edited by sometimes99er
  • Like 1
Link to comment
Share on other sites

Bottomline. As a programmer and looking to the future, I would like the non shared version - or could we have it all !?!?!!!? ;)

 

Thank you for your thoughts, but ... yes. :) You'll have ROM banks >6000->6FFF and as many RAM banks >7000->7FFF, and can bank switch both independently. So, you have both.

  • Like 2
Link to comment
Share on other sites

Thank you for your thoughts, but ... yes. :) You'll have ROM banks >6000->6FFF and as many RAM banks >7000->7FFF, and can bank switch both independently. So, you have both.

 

Excellent. Brilliant solution. Thanks. :thumbsup:

 

Any plans for a button to dump all of the 512K to the SD card ? Please. Software controlled dumps of any specific 4K bank to SD would be nice too (possible states, high scores, memory dumps, screen shots etc.). ;)

Edited by sometimes99er
Link to comment
Share on other sites

Any plans for a button to dump all of the 512K to the SD card ? Please. Software controlled dumps of any specific 4K bank to SD would be nice too (possible states, high scores, memory dumps, screen shots etc.). ;)

 

That's a nice idea, but it also eats up lots of resources. It also serves no "historical" purpose but only caters to newly developed programs. As such, I won't implement this for the release, but may evaluate this later after the dust has settled.

  • Like 1
Link to comment
Share on other sites

I thought you needed an external power supply? Or was that only if you attached it to the right of the Speech Synth?

Only if the speech synthesizer is in the way. I regularly run a modded speech synthesizer that passes the +5v, too. The speech synthesizer doesn't limit, it simply doesn't connect it.

 

But that is the sideport.

 

There are no active current limiters that I could find on either port.

 

-M@

  • Like 1
Link to comment
Share on other sites

With the talk of ram/rom, I am curious if it will be possible to emulate the 8k supercart by placing RAM at 0x6000-7fff?

 

Unfortunately, this is highly unlikely. The CPLD has only a limited amount of "logic", and spending some just to support one single cartridge is unreasonable.

 

There have been some suggestions here, like the cheat mode, but it turned out that this cannot be implemented without sacrificing the load performance, so I dropped it.

  • Like 1
Link to comment
Share on other sites

Only if the speech synthesizer is in the way. I regularly run a modded speech synthesizer that passes the +5v, too. The speech synthesizer doesn't limit, it simply doesn't connect it.

 

But that is the sideport.

 

There are no active current limiters that I could find on either port.

 

-M@

 

Though there is this little nugget ;)

post-48993-0-24574900-1491851100_thumb.jpg

Link to comment
Share on other sites

 

Unfortunately, this is highly unlikely. The CPLD has only a limited amount of "logic", and spending some just to support one single cartridge is unreasonable.

 

There have been some suggestions here, like the cheat mode, but it turned out that this cannot be implemented without sacrificing the load performance, so I dropped it.

 

It sounds like the FG99 is more or less finished. Do you have the specifications and/or any documentation ready?

Link to comment
Share on other sites

You probably wonder what's happening, so let me give you a short update.

 

Hardware and software for the FinalGROM is mostly done. What you see here is the final board (never mind the color), handsoldered by me.

 

post-35214-0-89989700-1492062641_thumb.jpg

 

This PCB order was only to confirm the working of the final board. About a week ago, I also ordered some assembled boards from a different supplier, also as a test. Since I've never ordered assembled boards before, I couldn't trust my KiCAD to generate a correct pick-and-place file. Should the assembled carts (due in about three weeks) work, I can put it a large order, and the fun begins.

 

Looking at the board, you'll notice that the SD module is flipped now. This was the only way to fit it into a cart shell (well, I need to confirm that yet). But you can also solder and glue a micro-SD adapter in place, if you prefer the smaller format.

 

The cart now has 1 MB of RAM. I'll put up the detailed specs and the manual in the next weeks.

 

  • Like 11
Link to comment
Share on other sites

You KNOW it's great when everyone say's, "+1" without even asking about the price... and in this case justifiably so. Once you use and populate this thing, most of you will never want to take it out of your TI. In fact, you'll wonder how you ever got along without it. It's a definite game changer.

 

In the future, if I'm asked to recommend any hardware to a returning TI'er, the FinalGROM 99 will be at the very TOP of that list in order of priority.

 

Hmmm.... time to consider a new label design.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...