8-Bit Show And Tell | What's a Leap Year? Calculating on Commodore 64 @8_Bit | Uploaded February 2024 | Updated October 2024, 14 hours ago.
2024 is a leap year, and February 29th is Leap Day! Can we calculate leap years on a Commodore 64 in BASIC and 6502 Assembly Language? Of course we can. We also learn about why we have leap years, Julian and Gregorian calendars, question if it's Simon's or Simons' BASIC, figure out binary long division, notice some strange coincidences, and see Robin's ancestors in some 1962 movie footage that is barely on-topic. It's fun!

Download the D64 with the source code:
8bitshowandtell.com/downloads/leapyear.d64

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Things mentioned in this video:
codebase64.org/doku.php?id=base:32_bit_hexadecimal_to_decimal_conversion
c64-wiki.com/wiki/Simons%27_BASIC
github.com/adrianglz64/snappyrom
store.go4retro.com/easyflash-3
tfw8b.com/product/kung-fu-flash
turbo.style64.org

Index:
0:00 About leap years
2:50 Julian Calendar leap year calculation in C64 BASIC
7:35 Gregorian Calendar calculation in Simons' BASIC
10:06 Assembly language version - load and run
12:11 Walk-through: main loop
16:45 Checking if leap year (divisible by 4)
18:34 Divide by 100
22:34 Gregorian checks, printing, tabs
27:05 A strange coincidence? Thanks!