The FinalGROM 99

[Asmusr]

This looks like the ultimate cartridge for assembly developers and will open up a lot of doors - for development as well as for distribution. I definitely also want one.

[+retroclouds]

One for me too please! :-)

[ralphb]

I appreciate all your interest, but there's no need to stake a claim here. Just send me an email when I'm ready; I hope there won't be a long wait after that.

[Omega-TI]

It's kind of nice to put all of the Rasmus games in one spot for easy access and play...

[ralphb]

This weekend, I received the professionally assembled FinalGROM sample, and they work beautifully!

 

 

And yes, you can see the professional work. No flux gunk, like on my boards. But I already knew from my plain PCBs that I mixed up two signals, so I had to add two wires on the backside. While I fixed the design, I also added one more feature. What could possibly go wrong?

 

Using this updated design, I already contacted two PCBA houses for a quote. The production will take up to 28 working days, though, so if everything goes according to plan, I'll have carts in early June. (The SRAM is apparently super weird -- they're either not there, or outrageously expensive. I resorted to supplying them with the ICs.)

 

I was less lucky posting the documentation today. GitHub mangled their Pages editor, so I'll need to get an extra tool before I can publish it.

[+jedimatt42]

That is pretty! Seriously pretty.

 

-M@

[Omega-TI]

I really like the new designs SD card connection point at the back of the cartridge!

 

[brain]

Ralph, you sure you don't want to skip the daughtercard and just do the SD card on the main board?

[eightbit]

I will take one of these the second they are available!

[tuf]

I hate to do this b/c I realize this is not yet a purchase thread, but here goes just in case it does turn into one:

 

Put me down for 1 when they're available

[ralphb]

Ralph, you sure you don't want to skip the daughtercard and just do the SD card on the main board?

 

Yes, I thought about that. An SD card adapter costs between €3 and €6 on my supplier sites, which is just outrageous. Of course I can get cheap Chinese ones, but then I usually don't get a datasheet, and most certainly not an official part number. Different adapters are mechanically incompatible, so I'd have to go with the expensive ones. Plus, I need to prolong the board so that the slot protrudes a little.

 

There is one relatively cheap Digikey adapter for €2,29 plus tax, but still, this would need additional development time.

[brain]

 

Yes, I thought about that. An SD card adapter costs between €3 and €6 on my supplier sites, which is just outrageous. Of course I can get cheap Chinese ones, but then I usually don't get a datasheet, and most certainly not an official part number. Different adapters are mechanically incompatible, so I'd have to go with the expensive ones. Plus, I need to prolong the board so that the slot protrudes a little.

 

There is one relatively cheap Digikey adapter for €2,29 plus tax, but still, this would need additional development time.

Well, I have this part, which looks to be an order of magnitude cheaper:

 

 

Would it be of help?

[ralphb]

I finally uploaded the preliminary documentation for the FinalGROM 99: https://endlos99.github.io/finalgrom99/.

 

You'll notice that I didn't implement System GROM mode and Cheat mode.

 

System GROM mode seems impractical for now, as the FinalGROM doesn't initialize fast enough to catch the first GROM address write. One could probably get around this if the system GROMs are still present in the console, but this seemed like missing the point. I decided to postpone this topic for later.

 

Cheat modes could not be implemented with the current architecture, as the bytes read from the SD card bypass the main program for efficiency. And after-load patching was also not possible, as the load is a sequential, one-shot process. I think the result wouldn't justify the necessary work. My recommendation is to patch images directly and simply use patched images as cheats.

 

The help text system and the dump I'm going to look at now. I also wondered if I should support MBX games natively, but there are already conversions that use 32K instead, so I probably won't.

[InfiniteTape]

I finally uploaded the preliminary documentation for the FinalGROM 99: https://endlos99.github.io/finalgrom99/.

 

That documentation is very well done. Great work!

[dphirschler]

Oh boy! I can't wait for these to go on sale.

 

Darryl

[+arcadeshopper]

Awesome!

 

Sent from my LG-H830 using Tapatalk

[x24b]

I'll have to dust-off my machine for this.

[iKarith]

.... it looks like the man is going to be very, VERY busy assembling carts when this project is ready.

 

I don't know about that. If he goes with a SMT microSD socket, possibility exists that the board can be made in small quantities at prices people will be happy to pay. For the Apple II, we have the Uthernet II cards. Glenn gets these things manufactured with the SMD components pre-applied. He solders the Ethernet connectors himself because the cost is prohibitive to have through-hole components installed on the board as well as SMD by the company he uses. Then it's just a matter of testing the things.

 

He went through 500 of them pretty quick. I dunno if there's call for that many FinalGROMs out there, but as these systems are gaining in popularity and still have _wide_ availability pretty cheaply, it's not hard to imagine. Especially since people around here are likely to want more than one.

 

If it can be done in some way that's compatible, I'd like to suggest some method of paging larger programs in. Mostly because Tursi's Dragon's Lair needs 128MB of ROM, and that's insane for any cartridge out there, but a drop in the bucket for a modern SD card.

 

Also, is there a possibility to perhaps have a file provide a name for carts that don't have one? Or maybe for carts that do but are big?

[iKarith]

Also, +1.

[weirdocollector]

As I already said, please book me for one [emoji2]

Edited May 10, 2017 by weirdocollector

[weirdocollector]

 

Edited May 10, 2017 by weirdocollector

[Omega-TI]

I'll have to dust-off my machine for this.

 

You... and I dunno how many others!

 

About 2 weeks after this thing hits the world market, I'm planning on another poll. I'm thinking we'll get some new and returning people, but I bet even some of the lurkers will come out of hiding for a while as well.

[Tursi]

 

 

Mostly because Tursi's Dragon's Lair needs 128MB of ROM

 

I won't be able to distribute DL as a freebie anyway, I need to report and pay royalties on each copy distributed. So to have a flash cart support it isn't high on the priority list.

[Asmusr]

If it can be done in some way that's compatible, I'd like to suggest some method of paging larger programs in. Mostly because Tursi's Dragon's Lair needs 128MB of ROM, and that's insane for any cartridge out there, but a drop in the bucket for a modern SD card.

 

From the documentation:

 

Reloading

Although 1024 KB is plenty of space for a TI 99 program, the FinalGROM 99 enables programs to reload and start other programs from the SD card. Any program type may load any program type.

To initiate the reload of a new program, the sequence >99, "RELOAD", >99 must be sent, followed by the program file data. To detect when the new image has been loaded, the program must watch addresses >6000->6200 for a non-zero word to appear. (For a reloaded ROM program, watching >6000suffices.)

Since the new image will overwrite the running image, the reload code must be relocated to RAM before it can be run.

[ralphb]

From the documentation:

 

Although 1024 KB is plenty of space for a TI 99 program, the FinalGROM 99 enables programs to reload and start other programs from the SD card. Any program type may load any program type.

 

Thanks, Rasmus. It should be added, though, that reloading 1 MB from the SD card is like loading a program from floppy, i.e., it takes a while. 14 seconds, to be precise.