The Retry System has a built-in saving system. You can configure what addresses it saves by editing two tables in retry_config/sram_tables.asm. To be able to be used, you need to enable !sram_feature in Global Settings - Save and SRAM Settings.
This table can be used to save custom values to SRAM, so they can persist when the console is turned off. By default it saves the custom checkpoint ram (so multiple midways will save properly) and the death counter.
save:
dl !ram_checkpoint : dw 192
; Feel free to add your own stuff here.
.not_game_over:
dl !ram_death_counter : dw 5
; Feel free to add your own stuff here.
.global:
; Feel free to add your own stuff here.
Each line is formatted as follows:
dl $XXXXXX : dw $YYYY
Where $XXXXXX is what RAM address to save. Make sure it's always 3 bytes long (i.e. use $7E0019 instead of $19 or $0019) and $YYYY is how many bytes to save at that address (remove the $ to use a decimal value).
For example, adding dl $7E1F3C : dw 12 will make the 1-Up checkpoints for all levels save. Make sure to always put a colon between the two elements!
The addresses you put under .not_game_over will be saved like usual, but they won't be reloaded from SRAM when getting a game over. This can be useful if you want some things to retain even if the player got a game over before being able to save them.
The addresses you put under .global behave differently than the others: they will be saved independently from the save slots, and are only loaded when booting the game. This can be used to save stuff that's global and not related to a specific save slot (for example like Jump 1/2's costumes, which when you unlock are then available in all save files and all successive playthroughs).
The global addresses are saved when you save the game normally, and they persist even when erasing save files (the only way to reset them would be to delete the .srm file from the computer). Since the normal save routine (and the Retry API - Save game routine) are tied to the current save slot, if you need to save them outside of a save file (for example on the title screen), you can use the Retry API - Save global variables routine.
save: table, you need to add the default values in the sram_defaults: table below.$7E0100-$7E1FFF you must change them to $400100-$401FFF and for addresses $7E0000-$7E00FF you must change them to $003000-$0030FF. Additionally, a lot of other addresses might be remapped to different locations (for more information see SMW SA-1 Pack docs).save and .not_game_over tables combined, and up to 162 bytes on lorom or 1021 bytes on SA-1 in the .global table.Here you specify the "default" values of the addresses you want to save, for when a new save file is started.
sram_defaults:
; Default checkpoint values (don't edit this!).
dw $0000,$0001,$0002,$0003,$0004,$0005,$0006,$0007
dw $0008,$0009,$000A,$000B,$000C,$000D,$000E,$000F
dw $0010,$0011,$0012,$0013,$0014,$0015,$0016,$0017
dw $0018,$0019,$001A,$001B,$001C,$001D,$001E,$001F
dw $0020,$0021,$0022,$0023,$0024,$0101,$0102,$0103
dw $0104,$0105,$0106,$0107,$0108,$0109,$010A,$010B
dw $010C,$010D,$010E,$010F,$0110,$0111,$0112,$0113
dw $0114,$0115,$0116,$0117,$0118,$0119,$011A,$011B
dw $011C,$011D,$011E,$011F,$0120,$0121,$0122,$0123
dw $0124,$0125,$0126,$0127,$0128,$0129,$012A,$012B
dw $012C,$012D,$012E,$012F,$0130,$0131,$0132,$0133
dw $0134,$0135,$0136,$0137,$0138,$0139,$013A,$013B
; Feel free to add your own stuff here.
.not_game_over:
; Initial death counter value (don't edit this!).
db $00,$00,$00,$00,$00
; Feel free to add your own stuff here.
.global:
; Feel free to add your own stuff here.
You can do db $XX,$XX,... for 1 byte values, dw $XXXX,$XXXX,... for 2 bytes values and dl $XXXXXX,$XXXXXX,... for 3 bytes values.
The amount of values of each entry should correspond to the dw $YYYY value in the save table (for example, the checkpoint values are 192, and the death counter values are 5).
Remember, if you have some addresses after .not_game_over and .global in the save: table, put their default values after .not_game_over and .global here also, in the same order.
Regarding the .global values, they will be initialized on game startup rather than on a new save file.