NGP Horoscope simulator

ngp_horoscope.py

# NGP Horoscope simulator v1.1
# furrtek 2021
# Based on algorithm found in ngp_bios.bin

import sys
from datetime import datetime

if len(sys.argv) == 1:
	print(sys.argv[0] + " DD/MM/YYYY")
	exit()
	
dob = datetime.strptime(sys.argv[1], '%d/%m/%Y')

current_date = datetime.today()
current_day = current_date.day
current_month = current_date.month
current_year = current_date.year

dob_day = dob.day
dob_month = dob.month
dob_year = dob.year

# 0 is Sunday
weekday = (datetime(current_year, current_month, current_day).weekday() + 1) % 7
#print("Weekday: %d" % weekday)

# January to December
zodiac_days = [20, 19, 21, 20, 21, 22, 23, 23, 23, 24, 23, 22]
zodiac_signs = [
	"Aquarius",
	"Pisces",
	"Aries",
	"Taurus",
	"Gemini",
	"Cancer",
	"Leo",
	"Virgo",                            
	"Libra",
	"Scorpio",
	"Sagittarius",
	"Capricorn"]
sign_remap = [11, 12, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
lookupA = [1, 7, 6, 5, 4, 3, 2,
	2, 1, 7, 6, 5, 4, 3,
	3, 2, 1, 7, 6, 5, 4,
	4, 3, 2, 1, 7, 6, 5,
	5, 4, 3, 2, 1, 7, 6,
	6, 5, 4, 3, 2, 1, 7,
	7, 6, 5, 4, 3, 2, 1]
lookupB = [0, 2, 1, 1, 2, 0, 3, 2, 3, 3, 0, 0, 1, 0, 1, 0]
lookupC = [3, 4, 4, 5, 4, 4, 3, 3, 2, 2, 1, 2, 2, 3, 3, 4, 5, 3, 1, 2, 3, 3, 2, 1, 3, 5, 4, 3]

e = current_year % 10 # Lowest digit in BCD

# ffcc00
dob_month -= 1
zodiac_sign = dob_month

if dob_day < zodiac_days[dob_month]:
	zodiac_sign = dob_month - 1
	if zodiac_sign < 0:
		zodiac_sign = 11	# Warp

print("Sign: %s" % zodiac_signs[zodiac_sign])

# ffcde6
zodiac_sign = sign_remap[zodiac_sign]

# ffce2c
d = current_day % 7
if d == 0:
	d = 7

if d <= weekday:	#ffce4b
	if dob_month == 0:
		dob_month = 12
	b = 7 - d

	if dob_month in [4, 6, 9, 11]:
		a = 30
	if dob_month != 2:
		a = 31
	else:
		if leap_year:	#ffce7a - TODO
			a = 28
		else:
			a = 29

	d = (a - b) % 7		#ffce86

b = zodiac_sign
if b < 8:
	b -= 1
else:
	b -= 8

a = d - 1
xsp6 = a
a += b
h = a if (a < 7) else (d + b) - 8
wa = lookupA[h * 7 + weekday]
h = (wa * wa) & 255

b = (zodiac_sign + e + current_month + h) & 3
var40c2 = b
d = (zodiac_sign * 2 + e + current_month + h) & 3
var40c4 = d
a = (zodiac_sign * 3 + e + current_month + h) & 3
var40c6 = a

if (b == d) and (b == a):
	if b == 2:
		var40c4 = 3
		var40c6 = 0
	elif a == 1:
		var40c4 = 2
		var40c6 = 3
	elif a != 0:
		var40c4 = 0
		var40c6 = 1
	else:
		var40c4 = 1
		var40c6 = 2
else:
	# ffcf6a
	hl = b * 4
	if b == d:
		var40c4 = lookupB[hl + a]
	else:
		if b == a:
			var40c6 = lookupB[hl + d]
		else:
			if d == a:
				var40c2 = lookupB[hl + d * 4]

# ffcfb7
d = lookupA[(xsp6 * 7) + weekday]
if current_day >= d + 7:
	b = (current_day - d) // 7

	var40c2 += b
	if var40c2 >= 4:
		var40c2 -= 4

	var40c4 += b
	if var40c4 >= 4:
		var40c4 -= 4

	var40c6 += b
	if var40c6 >= 4:
		var40c6 -= 4

# ffd049
zodiac_sign += weekday
level_money = lookupC[var40c2 * 7 + (zodiac_sign - 1 + b) % 7]
level_health = lookupC[var40c4 * 7 + (zodiac_sign + b * 2) % 7]
level_romance = lookupC[var40c6 * 7 + (zodiac_sign + 1 + b * 3) % 7]

sum = level_money + level_health + level_romance
level_general = sum // 3
if sum % 3 == 2:
	level_general += 1

print("MONEY: %d" % level_money)
print("HEALTH: %d" % level_health)
print("ROMANCE: %d" % level_romance)
print("GENERAL: %d" % level_general)

All I was able to find from that time is a partially commented disassembly of the NGPC bios: https://file.io/07BvQGXxmt5n
The horoscope stuff starts around FFCC00.

This is great, thanks! If I succeed in fully figuring it out I'll post a link to the repo here.