User:BaviH/Dr. Mario Gravity

Gravity

NES Version

When the 10th (20th, 30th, and so on) vitamin capsule appears in Dr. Mario's throwing hand, a sound effect plays and the drop speed of the vitamin capsules increases slightly. This speed up can happen up to a maximum of 49 times in a level, meaning there are a total of 50 possible drop speeds for each SPEED setting (LOW, MED, or HI).

Here are technical details for the NTSC game (PRG+CHR CRC32 198C2F41) and the PAL game (PRG+CHR CRC32 9735D267):

• A gravity table begins at memory address A795 in the NTSC game and memory address A79E in the PAL game. It consists of 81 one-byte entries (indexes decimal 0 to 80). The actual values in the memory addresses are zero-based: a value of 0 has an effect of 1 frame per row. The gravity table below shows the one-based "frames per row" values.

• A three-byte table of the starting indexes for each SPEED setting exists at memory address A38D in the NTSC game and memory address A396 in the PAL game. The contents are the same in both versions:

LOW	15
MED	25
HI	31

• A count of the number of times a speed up has occurred this level exists at memory address 8A (as well as having other copies at addresses A0, 30A, and 320).

• The starting index is added to the number of speed ups, and the result is used as an index into the the gravity table.

Here is the gravity table:

Index	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31	32	33	34	35	36	37	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53	54	55	56	57	58	59	60	61	62	63	64	65	66	67	68	69	70	71	72	73	74	75	76	77	78	79	80
NTSC frames per row	70	68	66	64	62	60	58	56	54	52	50	48	46	44	42	40	38	36	34	32	30	28	26	24	22	20	19	18	17	16	15	14	13	12	11	10	10	9	9	8	8	7	7	6	6	6	6	6	6	6	6	6	6	6	6	5	5	5	5	5	4	4	4	4	4	3	3	3	3	3	2	2	2	2	2	2	2	2	2	2	1
PAL frames per row	57	55	54	52	50	49	47	45	44	42	40	39	37	35	34	32	30	29	27	25	24	22	20	19	17	16	15	14	13	12	11	10	10	9	8	7	7	6	6	6	5	5	5	5	4	4	4	4	4	4	3	3	3	3	3	3	3	3	3	3	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	1
Ranges																LOW: indexes 15 to 64
																										MED: indexes 25 to 74
																																HI: indexes 31 to 80