bank switching XEGS cart: can it be switched off?

[Marius]

Todays modern flash based carts have a feature to switch the cart off, so you even can switch on basic or whatever while the flash cart is actually inserted in the atari.

 

I'm wondering: is this feature also available in the XEGS carts? I have plenty of them, and I want to use them for something else than that is on the carts now.

 

If these carts could be switched off by software, that would be great.

[Rybags]

The Help system of Atari800Win+ has a good description of most of the Rom types and banking schemes used.

 

XEGS carts, there's 3 or 4 types but there's always a fixed bank at $A000-$BFFF at the least.

Part of the reasoning could be handling of RESET - there is no Reset line on the cart port so in a situation where a cart is swapped out that if the user presses Reset the system won't see the cartridge on warmstart.

In fact the system would likely do a coldstart because the cart insert status is constantly monitored and as well as that there's a checksum of the top of cart ROM that is compared when you press Reset to determine if a cart swap has occurred.

 

In the case of Atarimax carts, there is a workaround - if you plug in the state and checksum values into the relevant OS variables when bank-switching the system will handle Reset properly. Although you're having to do 3 things there, so there's still the chance of it not working if the user presses Reset while a switch is in progress.

[thorfdbg]

 

XEGS carts, there's 3 or 4 types but there's always a fixed bank at $A000-$BFFF at the least.

Part of the reasoning could be handling of RESET - there is no Reset line on the cart port so in a situation where a cart is swapped out that if the user presses Reset the system won't see the cartridge on warmstart.

In fact the system would likely do a coldstart because the cart insert status is constantly monitored and as well as that there's a checksum of the top of cart ROM that is compared when you press Reset to determine if a cart swap has occurred.

 

According to the documentation I have, at least some XEGS carts can be disabled by setting bit 7 of CARTCTL ($d500). The workaround you describe actually goes for all cards, regardless of their internal wiring. You need to update the TRIG3SHADOW register to avoid a coldstart and a system lock-up.

[Rybags]

Some XE carts act as little more than virtual disks - the game code is copied then run from RAM. So I guess that could be one reason to disable the cart.

[Marius]

Well my goal is this:

 

I have this SIO2IDE 3.3a built in a nice cigar box, and although it is no longer my primary harddisk solution, I want to start using that one on the atari in the living room.

One downside to this interface is that it needs a little startup time. So when my daughter switches on the atari, BASIC comes up, and just after that Sio2IDE is ready to start.

 

I want this:

1) Atari on (with the cart I'm planned to make)

2) Software on cart makes the atari wait for 5 seconds

3) Cart is switched off automatically and atari reboots. Now the Sio2IDE boots.

 

With SIC cart I already made this. Works perfect. I also added a Sio2IDE config tool to this.

 

But... I do not want to waste a SIC! cart for that, so I thought: let me create this on a XEGS cart. I have zillions of these, waiting in a drawer to be used .

 

Ofcourse I know there are plenty other solutions and they all would work. But I want to give this idea a goal. So when indeed it is possible to find an XEGS cart that can switch itself of like it is completely invisible to the system, I would love that.

 

Perhaps midnight magic does it... that ones copy itself entirely to atari RAM and then runs from RAM. No bankswitching during running. I'm not sure Cart is switched off with this one.

[Rybags]

You could just hold Reset or keep pressing it until the 5 seconds is up.

Or, make yourself a custom OS that has some extra delay at startup - maybe have it optional, like hold SELECT to ask for the delay.

 

So, the delay is for a HDD to spin up?

[+CharlieChaplin]

Hmmm,

 

crazy idea... if a Basic program contains lots of data statements, you often see "please wait initializing" on the screen. Maybe you can code a small Assembler program that shows that info on the screen (using a pause or for/next loop) and after approx. 5-10 seconds you switch off the cart and do a coldstart, so that SIO2IDE is able to boot. Alternatively, what about the OS/BIOS of SIO2IDE - maybe there is some space in the OS/BIOS left to make the new assembler code part of the OS/BIOS that will display immediately until the SIO2IDE is ready to boot...?!?

 

I do have a few XEGS carts created+modified by Nir Dary that contain 64k programs that are copied into RAM and then the carts are switched off (since the programs require the RAM from 8000-BFFF). Alas, some code was not enough to switch the XEGS cart off, Nir always had to modify the XEGS pcb to accomplish this. Looks like most XEGS carts cannot be switched off by software... and I wonder which XEGS carts can be switched off ?

-Andreas Koch.

Edited March 2, 2014 by CharlieChaplin

[+JAC!]

>which XEGS carts can be switched off ?

Only those that Nir created. So if you REALLY want THAT kind a solution, using a plain AtariMax/SIC cart will be the "simplest".

You can put the plain .XEX file as autostart on it that delays, switches the cart off and boots.

Alternativly, the girl could hold down RESET while... erm, sorry, wrong solution :-)

Edited March 2, 2014 by JAC!

[Marius]

@rybags: it is for initialisation of Sio2IDE... it is kind of slow. As soon as it gets on, it takes around 5 seconds before it is operational (even with flash media)

 

@Jac: indeed reset won't do the trick... it is an XE.

 

Well I might go for the SIC solution then.