RAM/ROM switch on OSS cartridge?

[joeventura]

See this auction:

http://cgi.ebay.com/Atari-400-800-XL-compu...emZ320167988342

 

What is the purpose of the switch and the way it is labeled?

 

Thanks

[yorgle]

My guess is that this is a RAM cartridge with it's own powersupply (battery) and that one setting (marked RAM) simply provides additional RAM and the other (marked ROM) is really RAM holding a bootable OS. Keep in mind this is only a guess.

[+Larry]

See this auction:

http://cgi.ebay.com/Atari-400-800-XL-compu...emZ320167988342

 

What is the purpose of the switch and the way it is labeled?

 

Thanks

 

It looks to be a stock 2 X 2764 type cart. My guess would be that the switch allows shutting off the cart so that only the ram underneath is seen by the computer. Would work the same way as the OSS files SCOFF and SCON. The wires all appear to be attached to the component side of the pcb.

 

-Larry

[MEtalGuy66]

See this auction:

http://cgi.ebay.com/Atari-400-800-XL-compu...emZ320167988342

 

What is the purpose of the switch and the way it is labeled?

 

Thanks

 

It looks to be a stock 2 X 2764 type cart. My guess would be that the switch allows shutting off the cart so that only the ram underneath is seen by the computer. Would work the same way as the OSS files SCOFF and SCON. The wires all appear to be attached to the component side of the pcb.

 

-Larry

 

Thats a prototype cart.. It was used By OSS for development of their languages.

 

Heres how it works.. heh. Your gonna laugh.. Its the exact same bank switching logic that a normal Basic XL, basic XE, or Mac/65 cart uses.. They used equivelant density SRAMs instead of EPROMS.. The switch is tied to the WRITE ENABLE on the SRAMS.. heh.

 

So.. by flipping the switch to "ram" they can then toggle the bits necessary to switch banks, and actually WRITE each "chunk" (of the ROM image they were developing) into the SRAM.. Then, they flip the switch to "ROM" and as long is power is maintained to the cart, it acts like an actual ROM based OSS cart...

 

Kewl Idea, eh?

[yorgle]

Would it be useful for anything other than developing languages, e.g., as a programmable cartridge to store games, programs, etc.?

[MEtalGuy66]

Would it be useful for anything other than developing languages, e.g., as a programmable cartridge to store games, programs, etc.?

 

 

Sure, but anything you put on it has to be coded for OSS's proprietary bank-switching scheme.

 

 

So it wouldnt be real useful for developing stuff for "normal" atari carts (if there is such a thing.) It doesnt match the normal atari 8k/16k cart standard, nor does it match teh XEGS supercart standard. Whatever you developed for it would also have to be used on an OSS bank-switched cart.

 

Also, as soon as you turn the power off, or un-plug the cart, it's gone..

 

 

Heres what you could do with it..

 

get ROM images of all the OSS cart ROMs.. and save them to your atari's hardisk. Then write a simpleprogram that switches the banks of the cart, one at a time, and writes the ROM image of whichever .ROM file you specify into the cart, in the appropriate way.. Then you could use that OSS language.. And when you want to switch, just "write" the next language into it teh same way..

 

You can take a normal OSS cart and stick a 27512 EPROM in it, with 2 switches, and have all 4 langauges in ROM on a single cart, hard-switchable, which makes alot mre sense and is easy to do..

 

So.. NO.. Its just a novelty for collectors, really..

[yorgle]

Would it be useful for anything other than developing languages, e.g., as a programmable cartridge to store games, programs, etc.?

 

 

Sure, but anything you put on it has to be coded for OSS's proprietary bank-switching scheme.

 

 

So it wouldnt be real useful for developing stuff for "normal" atari carts (if there is such a thing.) It doesnt match the normal atari 8k/16k cart standard, nor does it match teh XEGS supercart standard. Whatever you developed for it would also have to be used on an OSS bank-switched cart.

 

Also, as soon as you turn the power off, or un-plug the cart, it's gone..

 

 

Heres what you could do with it..

 

get ROM images of all the OSS cart ROMs.. and save them to your atari's hardisk. Then write a simpleprogram that switches the banks of the cart, one at a time, and writes the ROM image of whichever .ROM file you specify into the cart, in the appropriate way.. Then you could use that OSS language.. And when you want to switch, just "write" the next language into it teh same way..

 

You can take a normal OSS cart and stick a 27512 EPROM in it, with 2 switches, and have all 4 langauges in ROM on a single cart, hard-switchable, which makes alot mre sense and is easy to do..

 

So.. NO.. Its just a novelty for collectors, really..

 

As I thought... beyond my simple uses. I see there's a similar cart called "Persistent RAM" on ebay right now. Any idea what that's all about?

[sup8pdct]

Would it be useful for anything other than developing languages, e.g., as a programmable cartridge to store games, programs, etc.?

 

 

Sure, but anything you put on it has to be coded for OSS's proprietary bank-switching scheme.

 

 

So it wouldnt be real useful for developing stuff for "normal" atari carts (if there is such a thing.) It doesnt match the normal atari 8k/16k cart standard, nor does it match teh XEGS supercart standard. Whatever you developed for it would also have to be used on an OSS bank-switched cart.

 

Also, as soon as you turn the power off, or un-plug the cart, it's gone..

 

 

Heres what you could do with it..

 

get ROM images of all the OSS cart ROMs.. and save them to your atari's hardisk. Then write a simpleprogram that switches the banks of the cart, one at a time, and writes the ROM image of whichever .ROM file you specify into the cart, in the appropriate way.. Then you could use that OSS language.. And when you want to switch, just "write" the next language into it teh same way..

 

You can take a normal OSS cart and stick a 27512 EPROM in it, with 2 switches, and have all 4 langauges in ROM on a single cart, hard-switchable, which makes alot mre sense and is easy to do..

 

 

This is what I have done with my OSS super cart. It has basic XL, basic XE, action and Mac65 all in one.

There are 2 versions of the oss supercart. one which is very similar to the one pictured with 2 eproms and another with a single eprom.

The code from each type is not interchangeable between the 2 versions, how ever, I have managed to do it with a bit of editing of the rom code. One bit has been changed in the bank switching logic so it wasn't too hard to do.

Also tho I am not 100% sure on this. the 2 eprom version, the lower 4K bank could be switched off and the ram under it could be accessed. the single rom version couldn't do this.

 

James