About wAxpander - Chysn/VIC20-wAx2 GitHub Wiki

wAxpander is a cartridge that includes one 8K ROM chip containing wAx2 at $A000 (Block 5), and 27K of RAM:

• 3K at $0400-$07FF
• 24K at $2000-$7FFF (Blocks 1, 2, and 3)

When you turn on your VIC-20 with wAxpander installed, the BASIC banner will indicate 28159 bytes free, which includes the on-board 3.5K plus the 24K starting at Block 1. The 3K at $0400 will be available for machine code, or wAx BASIC stages. Screen and color memory will be positioned as usual with 8K+ expansion.

wAx contains software to configure start-up memory. This software, MEM CONFIG, is the default user plug-in when wAx is started from a wAxpander cartridge. To configure memory with MEM CONFIG, do the following:

SYS 40960
.U 0  ; TO RESTART THE VIC-20 AS UNEXPANDED
.U 3  ; TO RESTART THE VIC-20 WITH 3K EXPANSION
.U 8  ; TO RESTART THE VIC-20 WITH 8K EXPANSION
.U 16 ; TO RESTART THE VIC-20 WITH 16K EXPANSION
.U 24 ; TO RESTART THE VIC-20 WITH 24K EXPANSION

Notes

• MEM CONFIG restarts the VIC-20 and wAx
• Screen and color locations will be appropriate for the configuration selected (e.g., default for 0K and 3K, and moved for 8K and up)
• Regardless of the BASIC expansion configured, the remaining RAM will be available to you