Castlevania II - Belmont's Revenge:RAM map
Please add more.
Legend: [u] is unsigned, [s] is signed, [d] is binary-coded decimal.  is a 2 byte word,  and so on likewise. [b] is big-endian; otherwise, values are assumed to be little-endian.
During entity update routines, register d stores the high byte of the entity data. Belmont's data begins at c000, so d is always c0 during belmont's update routine. Most of Belmont's entity data, such as the velocity data, repeats every 0x100 bytes for subsequent entities.
0x7FFF [u] index of currently-loaded swappable bank. 0xC001 Belmont state (0: standing. 1: walking. 2: crouching. 3: jumping.) 0xC002 Belmont's substate (0: none. 1: attacking, including both whip and subweapon) 0xC008 flags set when Belmont is hurt? Reset bits 0 and 1 to induce iframes; set bit 7 to cause knockback. 0xC009 Belmont's facing (CHR code). Bit 5 is Belmont's facing (20: left. 0: right.); bit 6 is Belmont's vertical flip, etc. 0xC00A Belmont's image. (see "Images" in ROM map.) 0xC00B Belmont's animation frame minus animation base (?) 0xC00C Belmont's animation timer (when walking, repeatedly counts down from C to 0) 0xC00F [s2] Belmont's Y velocity. Negative is upward 0xC011 [u] Belmont's Y subpixel 0xC012 [u] Belmont's Y pixel 0xC014 [s2] Belmont's X velocity. Negative is leftward. 0xC016 [u] Belmont's X subpixel 0xC017 [u] Belmont's X pixel 0xC018 [u] hitstun 0xC300 [u] subweapon projectile id. (0 if no subweapon being thrown currently; 1 if cross/axe; 2 if holy water.) 0xC301 [u] subweapon mode. (0: belmont is still winding up to toss. 1: in the air. 2: become flame/return [cross]) 0xC880 game mode (0: konami logo. 1: title screen. 2: title fade-in. 3: stage select and title screen selected. 4: stage entry. 5: normal gameplay. 6: death. 7: game over. 9: Credits. D: password entry. E: intro reel.) 0xC882 global 1-byte game timer 0xC886 current input (1: right. 2: left. 4: up. 8: down. 10: A. 20: B. 40: select. 80: start) 0xC887 input pressed (like 0xC886, but only what was just pressed this frame.) 0xC8C0 current stage (0: plant (glitched). 1: plant. 2: crystal. 3: cloud. 4: rock. 5: Drac 1. 6: Drac 2. 7: Drac 3.) 0xC8C1 current substage (initially 0, increments every time belmont passes through a door.) 0xC8C2 [d3] points/score 0xC8C5 [d] lives ("rest") 0xC980... array of values to copy to vram during the next vblank. Format is: - [2 bytes] address to update - [1 byte] stride (e.g. 1 to edit consecutive values) - [...] any data other than $FF - [1 byte] $FF terminator. Can be followed by more such packets. 0xCBE0... array of what lanterns have been smashed. (e.g. if Belmont returns to this area, then the lantern will remain gone.) 0xC8D0 subweapon (0: none. 1: axe (us) / cross (jp). 2: holy water) 0xCC80 [d2] time remaining 0xCC86 [d] hearts 0xCC89 [u] Belmont's hitpoints 0xC88C [u] next free index of $c980 array plus $80. 0xDEA0 [u] entity loading: x position 0xDEA1 [u] entity loading: y position 0xDEA4 [u] entity loading: index 0xFF80-0xFFFE stack (127 bytes)
Each entity has 20 bytes of data, located at **00 (where ** ranges from C0-D7).
- 00: entity ID (see the ROM map for a listing)
- 01: state?
- 05: entity load index (see $DEA4)
- 09: sprite flags (flip, palette, etc.)
- 0A: image (see "Images" in ROM map)
- 0B-0D: animation data (TODO)
- 0F: [s2] Y velocity (subpixel, pixel)
- 11: [bu2] Y position (pixel, subpixel)
- 14: [s2] X velocity (subpixel, pixel)
- 16: [bu2] X position (pixel, subpixel)
- 18: timer