Games That Don't Work on the Beige TI-99/4a?

[Tempest]

As we all know the later beige version of the TI-99/4a came with an updated BIOS that supposedly had a locked out 3rd party carts and stopped them from working. Does this actually happen? I've never heard of people having games that don't work on the beige TI and can't find a list of non-working programs anywhere. My beige TI is in much nicer shape than my silver one and I'd like to use it (has a handy dandy reset button that someone installed as well) but if it's going to cause problems with certain programs I'll pass.

 

Tempest

[oracle_jedi]

Some beige consoles had the 1981 ROM like the last of the black/silver consoles.

 

Later beige consoles had the V2.2 ROM.

 

The V2.2 shows up at power up, with a copyright date of 1983. If you have this model, Atarisoft cartridges wont play, plus I am guessing any cartridge that by-passes the GROM. Beige consoles with the 1981 ROM play Atarisoft games just fine.

 

Corcomp did sell an adapter to defeat the lock-out, I have seen only one come up on Ebay.

 

My beige console has a 1981 ROM and plays Atarisoft games. However, side-car games like Miner 2049er do not play, the title never appears in the opening menu. I am guessing other side car games like Espial, Arcturus and Killer Caterpillar would also refuse to play.

[Tempest]

I wonder if I can just do a Mother Board swap between my two consoles?

 

The sidecar thing wouldn't bother me too much as the only one I own is Miner (good luck getting the others). Still, that makes me wonder if there are other incompatibilities that we just don't know of.

 

 

Tempest

[JamesD]

Can't you just change the ROM instead of the entire motherboard.

[Tursi]

The ROMs are soldered.. and it's the GROMs that have the difference, meaning you can't even burn your own replacements. The main 'lock out' is that they no longer scan the ROM cartridge memory for a header.

 

I'm not aware of any changes that should prevent the side cars from working, especially since the 1981 motherboards are (as far as I have seen) all the same... the updated motherboard came with the updated ROMs.

 

That said, if you were somehow stuck with a 2.2 motherboard as your only machine and didn't want to replace it with a cheap console off EBay, there are numerous ways around it... a RAMdisk with the boot menu can launch them, for instance.

 

It is a small problem since most of the new carts are currently ROM-based. I had intended to program an Atmel as a GROM replacement to see what performance was like. Will get to that soon-ish.

[zylon]

I'll have to check mine sometime. Somebody gave me a beige one a few years ago and I've never even turned it on.

[Tursi]

You can tell by looking at the side port actually. Mainbyte has a nice page with the differences and photos: http://www.mainbyte.com/ti99/computers/ti99qi.html

[S1500]

Can't you have some Game Genie-like thing in the middle? Ooh that could be fun.

[Tursi]

You could in theory. All you need is to get enough code running to read the cartridge header and start the code. The problem is getting that code going without the GPL hook needs something either in a custom GROM (which we don't have yet) or something that hijacks the powerup vector. Not sure if you can do that through the cart port, it's missing a few important pins.

 

But if you had a game genie like device with a GROM or GROM simulator in it that did that much, it would work fine. Likewise, if you can run your own assembly code (like, say you have Editor/Assembler installed in the console), you just need a couple lines of assembly to launch the cart. There's no lockout except that it doesn't offer the ROM-based carts in the startup menu.

 

The reason you don't see many workarounds is that it's not actually a big problem. The v2.2 consoles are actually relatively rare compared to the v1.x consoles. I guess there's not enough demand to bump up their prices but I don't know of anyone who's actually stuck, and if you were, someone would probably ship you a free console for the asking to get you unstuck.

[S1500]

I can understand why TI would want to lock out un-licensed 3rd party carts($), but the side effect is that it really can kill the popularity of the console or computer. Sure, it didn't hurt Nintendo for the NES, but....

[Tempest]

Turns out my beige TI is the original ROM and not a V2.2. Not only does it look better (the aluminum on my other one is all dented) but it seems to work better as well (no more screwy video flicker). Someone even installed a reset button on it for me which is really handy. Now if only they made a beige speech adapter...

 

Tempest

[zylon]

Update: My free beige ti99 does play the 3rd party games. I finally got around to buying a game to try. My side port has the copper and 1981 comes up on main screen.