BS-X BIOS/RAM map

The following article is a RAM map for BS-X BIOS.

$7E0020-$7E0022 - 24-bit-address storage (for SPC stuff?)

$7E0100         - Value to store in $2100 (FBLANK / Brightness)
$7E0101         - $2101 buffer - Object Size and Object Base

$7E0104         - $2105 buffer - BG Mode
$7E0105         - $2106 buffer - Mosaic
$7E0106         - $2107 buffer - BG1 Tilemap Address and Mirroring
$7E0107         - $2108 buffer - BG2 Tilemap Address and Mirroring
$7E0108         - $2109 buffer - BG3 Tilemap Address and Mirroring
$7E0109         - $210A buffer - BG4 Tilemap Address and Mirroring
$7E010A         - $210B buffer - BG1/2 Tileset Address
$7E010B         - $210C buffer - BG3/4 Tileset Address
$7E010C         - $211A buffer - Mode 7 Rotation/Scaling Mode Settings
$7E010D         - $2123 buffer - Window BG1/BG2 Mask Settings
$7E010E         - $2124 buffer - Window BG3/BG4 Mask Settings
$7E010F         - $210D buffer - BG1 H-Scroll Low Byte
$7E0110         - $210D buffer - BG1 H-Scroll High Byte
$7E0111         - $210E buffer - BG1 V-Scroll Low Byte
$7E0112         - $210E buffer - BG1 V-Scroll High Byte
$7E0113         - $210F buffer - BG2 H-Scroll Low Byte
$7E0114         - $210F buffer - BG2 H-Scroll High Byte
$7E0115         - $2110 buffer - BG2 V-Scroll Low Byte
$7E0116         - $2110 buffer - BG2 V-Scroll High Byte
$7E0117         - $2111 buffer - BG3 H-Scroll Low Byte
$7E0118         - $2111 buffer - BG3 H-Scroll High Byte
$7E0119         - $2112 buffer - BG3 V-Scroll Low Byte
$7E011A         - $2112 buffer - BG3 V-Scroll High Byte
$7E011B         - $2113 buffer - BG4 H-Scroll Low Byte
$7E011C         - $2113 buffer - BG4 H-Scroll High Byte
$7E011D         - $2114 buffer - BG4 V-Scroll Low Byte
$7E011E         - $2114 buffer - BG4 V-Scroll High Byte
$7E011F         - $2125 buffer - Window OBJ/MATH Mask Settings
$7E0120         - $2126 buffer - Window 1 Left Position (X1)
$7E0121         - $2127 buffer - Window 1 Right Position (X2)
$7E0122         - $2128 buffer - Window 2 Left Position (X1)
$7E0123         - $2129 buffer - Window 2 Right Position (X2)
$7E0124         - $212A buffer - Window 1/2 Mask Logic (BG1-BG4)
$7E0125         - $212B buffer - Window 1/2 Mask Logic (OBJ/MATH)
$7E0126         - $212C buffer - Main Screen Designation
$7E0127         - $212E buffer - Window Area Main Screen Disable
$7E0128         - $212D buffer - Sub Screen Designation
$7E0129         - $212F buffer - Window Area Sub Screen Disable
$7E012A         - $2130 buffer - Color Math Control Register A
$7E012B         - $2131 buffer - Color Math Control Register B

$7E012D         - $2132 buffer - Color Math Sub Screen Backdrop Color RED (without #$20)
$7E012E         - $2132 buffer - Color Math Sub Screen Backdrop Color GREEN (without #$40)
$7E012F         - $2132 buffer - Color Math Sub Screen Backdrop Color BLUE (without #$80)
$7E0130         - $2133 buffer - Display Control 2

$7E0135         - ??? (used at $80/8FF0)

$7E013A         - $420C buffer - HDMA Flags

$7E021B         - Value stored in $2100 (FBLANK / Brightness)

$7E0661-$7E0662 - ??? (used at $80/8F9D)
$7E0663-$7E0664 - ??? (used at $80/8FA3)
$7E0665-$7E0666 - Buffer for Direct Page (at Program Start)

$7E0729         - VRAM Address for DMA at $80/9C4E

$7E0742         - Flag for VRAM DMA at $80/9C4E

$7E13D1         - Some Download(!?!) related flag?

$7E143F         - Error Counter at Program Start Up?

$7E1441         - Index for Jump Table at $80/BD79, gets executed at $80/BD6C

$7E1C00-$7E1E1F - OAM buffer
$7E1E20-$7E1EFF - Stack

$7E7600-$7E7DFF - Buffer for VRAM data, see $80/9C4E