OSS ACTION! programming language

[+MrFish]

There's also this Atari BASIC machine language subroutine that was published in Compute magazine. It doesn't include the source code, but it could be disassembled easily enough.

 

 

Access - 130XE Banked RAM.txt

 

[rsh]

1 hour ago, rsh said:

Yep PORTB magic! ... I would be interested in looking at that same basic program as well.  Do you remember what/where I could get it.  I found a page but can't seem to find the full code behind it.

I found it https://archive.org/details/1985-11-anticmagazine/page/n55/mode/2up   

In the text of the mag.  Interesting thing is it seems to be switching modes as well as banks.  Not sure why it does this yet (see below). 

 

There are 4 modes to toggle for extended Ram.  I'm thinking the "extend" command in Basic XE put's you in: "CPU extended RAM mode" and automatically moves your program in to secondary bank area.

 (referenced modes here https://www.atariarchives.org/mapping/appendix16.php )

    MODE                BANK
No. 6502   ANTIC        No.    Address
0   Extd   Extd         0      $0000-$3FFF
1   Main   Exd          1      $4000-$7FFF  
2   Extd   Main         2      $8000-$BFFF
3   Main   Main         3      $C000-$FFFF

POKE 54017, 193 + (MODE * 16) + (BANK * 4)     

The above program is doing this:

 

Bank 0 or (1 in program):  POKE 54017, 193 + (1 * 16) + (0 *4) = POKE 54017, 209          Mode (extd/extd)

Bank 1 or (2 in program): POKE 54017, 193 + (1 * 16) + (1 *4) = POKE 54017, 213               "

Bank 2 or (3 in program):  POKE 54017, 193 + (1 * 16) + (2 *4) =  POKE 54017, 217              "  

Bank 3 or (Main in program):  POKE 54017, 193 + (3 * 16) + (3 *4)   = POKE 54017, 253    Mode (main/main)

 

I believe Basic XE uses this mode:  Poke 54017,193   (to start, the move and bput/bget commands must set the Bank and buffer bank data for read/write)

1   Main   Exd          1      $4000-$7FFF  CPU extended RAM mode

 

The question now is which mode to pick for ACTION! ..  I will try and copy Basic XE's mode and usage and maybe implement the video extended RAM mode (this is like a giant video ram disk)

both would solve my problem. 

 

 

[rsh]

2 hours ago, MrFish said:

There's also this Atari BASIC machine language subroutine that was published in Compute magazine. It doesn't include the source code, but it could be disassembled easily enough.

 

 

Access - 130XE Banked RAM.txt 9.24 kB · 2 downloads

 

Nice!  This is cool it says you access all 65K without having to worry about the 16K bank limit.   I wonder if it will split read/write across banks as well.   Can I shove that in to ACTION! lol not sure but seems to be very clean.  Thanks!

Edited December 29, 2020 by rsh

[+MrFish]

24 minutes ago, rsh said:

Nice!  This is cool it says you access all 65K without having to worry about the 16K bank limit.   I wonder if it will split read/write across banks as well.   Can I shove that in to ACTION! lol not sure but seems to be very clean.  Thanks!

 

I've used this for years in Turbo-BASIC XL programs. It works great and is also relocatable (just don't relocate to an area of RAM in the banking window!)

 

Yes, it will read/write across banks. You don't have to concern yourself with banks when using it. It just treats extended RAM as one giant array of 64k bytes (0 to 65535), from the user side.