Upcoming Jaguar Game Drive Cartridge

[DoTheMath]

I'm glad to see you seem to have overcome some of the problems you had.

Can't wait!

 

So I should be able to detect a keypress combination and reset the console.

Woudn't there be interference if using part of an already existing combination?

[Zerosquare]

You could choose something that's unlikely to be already used, like * + 0 + #.

Edited September 14, 2017 by Zerosquare

[SainT]

You could choose something that's unlikely to be already used, like * + 0 + #.

 

I was thinking *# held for like 3 seconds or something. So *# immediately does a software reset (if the game supports it), then held down for longer does a full reboot.

[productof76]

I'm glad to see you seem to have overcome some of the problems you had.

Can't wait!Woudn't there be interference if using part of an already existing combination?

17 buttons on a standard Jag Pad... means how many combinations? ...just DoTheMath!

[Zerosquare]

I was thinking *# held for like 3 seconds or something. So *# immediately does a software reset (if the game supports it), then held down for longer does a full reboot.

Pretty clever, I think that's a good idea.

[+Sporadic]

Can you go for an 11 button combo so the player has to use their nose too?

 

(The 3 second press sounds perfect)

[DoTheMath]

I was thinking *# held for like 3 seconds or something. So *# immediately does a software reset (if the game supports it), then held down for longer does a full reboot.

Nice! I think Doom needs some seconds to register the "* + # + Option" to reset the memory but that won't be needed here anyway.

 

How will we have to handle save files by the way?

[SainT]

On 9/14/2017 at 10:33 PM, DoTheMath said:

Nice! I think Doom needs some seconds to register the "* + # + Option" to reset the memory but that won't be needed here anyway.

How will we have to handle save files by the way?

If there any conflicts with anything I will resolve them in terms of the button combo.

 

I'm planning on having the EEPROM save stored on the memory card alongside the rom image. So with your game.j64 you'll have a game.sav which is read in with the rom image and saved back to the memory card as its altered by the jaguar. In theory you could have multiple saves for a game if you wanted...

Edited October 25, 2019 by SainT

[DoTheMath]

I'm planning on having the EEPROM save stored on the sd alongside the rom image. So with your game.j64 you'll have a game.sav which is read in with the rom image and saved back to the sd card as its altered by the jaguar. In theory you could have multiple saves for a game if you wanted...

That's pretty cool, pretty much what i expected. Thanks for you answers!

[mr-atari]

I definitely want one......

[Krip316]

I definitely want one......

[DoTheMath]

Looks like your project has been mentioned in the DF Retro episode on Doom Ports.

[leech]

Hmm, Maybe Pause/Option at the same time for a reboot? I don't think pushing those two together are used anywhere, are they?

[mrpjones]

Add me to the list please! Assume you're adopting a similar approach to the Lynx, working your way down a list of names? Very happy with the work on the Lynx card so looking forward to something similar for the Jag!

Edited September 20, 2017 by mrpjones

[Krip316]

Add me to the list please! Assume you're adopting a similar approach to the Lynx, working your way down a list of names? Very happy with the work on the Lynx card so looking forward to something similar for the Jag!

[leech]

Ha, I probably need to use that Gif far more frequently in life than I should....

[Krip316]

Ha, I probably need to use that Gif far more frequently in life than I should....

Yes! I tend to use it more than I'd like to.

[Hastor]

I don't see people saying "I definitely want one" as anything but expressing interest and encouragement that there will be a good demand for this.

Of course the first post covers asking about lists and stuff, but I think that person was probably just excited about the project, not asking for a list like the more recent one

Mod's call in the end though.

[SainT]

I've had a fun few days writing a bare bones game engine for the Jaguar -- it's been a few years since I've ported my old game engine to a new platform, so it's been nice to resurrect some old code. I've got a reasonably nice display system with sprites and console working, so now's time for the fun bit of setting up the boot sector / menu section on the flash and getting it flashing the menu section from the memory card on the cart. This will mean no more unplugging the cart and programming via my custom external programmer! w00t! Then it will be shortly followed by programming / running code via USB.

Edited October 25, 2019 by SainT

[SainT]

I'm having a really odd issue running code on the Jaguar. For some really bizarre reason, for no apparent reason, code is hanging. This is one of those really weird issues where adding code to try and narrow down where the issue is, actually stops the code hanging.

 

I can actually add code which is not run and the hang disappears. I've checked the code generated, and it cannot be directly effecting the hang. My gut feeling is either alignment issues caused by the change in code size, but looking at the map files everything looks ok. Next I tend to think uninitialised variables, but I'm clearing the BSS, so it shouldn't be that either.

 

Oh, and I should say, the code works fine in VJ, so it's something odd. Annoyingly though if I cant add any code to trace where the issue is happening, and without a hardware debugger, tracking it down is next to impossible. My next feeling is something interrupt-y..... but quite how code size is affecting things like this, is bloody mental.

 

Is anyone aware of any weird issues with the Jaguar hardware? I'm just using the 68000 here, no GPU or DSP.

[+CyranoJ]

Stick a .phrase above anything accessed by the GPU/DSP and make sure the OLP is phrase aligned.

[SainT]

Tracked it down -- gut instinct was right, uninitialised variable from data in the main heap. I was right in thinking it couldn't be BSS, and VJ and a real Jaguar will naturally have a very different starting state for untouched memory. That was unpleasant.

 

But on the upside, I now have a protected 16K boot section which contains the failsafe booter and recovery console and a 112K menu section for the updatable menu code. For now I can update the booter and menu from the memory card from the recovery console. If the menu checks out OK, this is booted after the splash screen by default unless you press OPTION to get into the recovery console. This is the same as my NeoGeo Pocket cart.

 

And I've got to use my compression code I wrote ages ago, too, which is nice! It's actually pretty good, about on-par with zip (for the small datasets I'm using), but the decompression is very simple. Need to write an optimised depack routine though. The booter and menu and decompressed from the cart into main ram and executed from there allowing full access to the emulated cart space when running.

 

Really starting to get somewhere...

Edited October 25, 2019 by SainT

[+Saturn]

Glad you worked it out! Was getting nervous there for a sec

[+madman]

Glad you worked it out! Was getting nervous there for a sec

Nervous about what?

[leech]

I've had a fun few days writing a bare bones game engine for the Jaguar -- it's been a few years since I've ported my old game engine to a new platform, so it's been nice to resurrect some old code. I've got a reasonably nice display system with sprites and console working, so now's time for the fun bit of setting up the boot sector / menu section on the flash and getting it flashing the menu section from the SD card on the cart. This will mean no more unplugging the cart and programming via my custom external programmer! w00t! Then it will be shortly followed by programming / running code via USB.

This comment made me think of one of the Atari ST menu disks which had a little mini platformer game as the game selector. Damned if I can remember which disk it was though.... but that would be awesome as a Jag launcher.