Ram OS Swap for XL/XE?

[+Larry]

Does anyone know of software to make a ram OS (switcher) for the XL/XE? I'm aware of the basic requirements, but I'm hoping to find a generalized "maker" that would read a rom/bin file and make the swap. This is an XE to XE type swap, not an XE to 800 type (if that makes any difference).

 

Thanks,

Larry

[Rybags]

A short assembly program would do the trick.

 

Would this run with BASIC enabled, or would it be with/without?

 

I guess the easiest method would be to have your customized OS load around $4000, then have a routine which copies it to RAM under the OS.

 

Then, have a short initialization program that runs each time you press RESET.

[+Larry]

A short assembly program would do the trick.

 

Would this run with BASIC enabled, or would it be with/without?

 

I guess the easiest method would be to have your customized OS load around $4000, then have a routine which copies it to RAM under the OS.

 

Then, have a short initialization program that runs each time you press RESET.

 

Hi Rybags-

 

Without Basic -- I want to use a disk-based assembler.

 

Thanks,

Larry

[Rybags]

So, are you going to write it yourself?

 

It would be pretty easy. Just have it as a binary file which you can then just append to any modified ROM images you create.

 

When you disable the OS to copy stuff to the RAM, you just have to disable interrupts.

 

Simple case of LDA #0, STA $D40E, SEI

 

CLI, LDA #$40, STA $D40E when you're done.

[+Larry]

So, are you going to write it yourself?

 

It would be pretty easy. Just have it as a binary file which you can then just append to any modified ROM images you create.

 

When you disable the OS to copy stuff to the RAM, you just have to disable interrupts.

 

Simple case of LDA #0, STA $D40E, SEI

 

CLI, LDA #$40, STA $D40E when you're done.

 

My first choice is to never "reinvent the wheel," especially if it is in assembler. I'm pretty sure this has been done before and is in print (probably Analog or maybe Antic).

 

Second choice is to roll-my-own -- I found something similar this AM called "Swap Dos" from an old Creative Computing "Outpost Atari" column. The source code is there, and I probably can adapt it. I'll look a bit longer, and then if I don't find it, I'll have a go at it.

 

Thanks for the outline/info.

-Larry

[JayoK]

So, are you going to write it yourself?

 

Source code to do this is published in Mapping the Atari by Ian Chadwick. No need to reinvent this wheel I'm sure there's a copy on line

[+Larry]

Source code to do this is published in Mapping the Atari by Ian Chadwick. No need to reinvent this wheel I'm sure there's a copy on line

 

Thanks, Jayok-

 

I knew I had seen it somewhere. It's there in Appendix 12, p 216 - 219. I also found another one today in Analog April, 1985. "RamOS for XL's."

 

The one in Mapping appears a little more complete, though, with more code commenting.

 

-Larry