GatKong's comments:

This Yore Pack's goal is to showcase the original presentation, where available, for the various blocks, items, Advancements, sounds, drops, and structures of Minecraft as they were when each thing was first introduced. The comments below explain various "old school" texture choices, where some explanation would be helpful or interesting.

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### Achievements
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All the acheivements pre v1.9 are back, like "Diamonds to You", "On A Rail" and "When Pigs Fly."

Overpowered achievement originally erroneously stated "Deal eight hearts of damage in a single hit"

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### Blocks
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All blocks used to face left, not right, until 1.9.

Beacon in this pack is a mixture. It uses the original 12w36a texture for the beacon itself (minus the complex 3D animation, which can't be done with a texture pack alone), and the beam from 12w38a (although I've included the 12w36a texture if you really want to be authentic oldschool).

Brewing stand when it appeared in Beta 1.9-pre3 had no base, but it was corrected during the same release. Otherwise, it appears as it did then.

The original cake had six slices, not seven.

Chiseled Stone Bricks had no name when the image was introduced in 1.2.1, but they were referred to as Circle Stone Bricks. They were named Detailed Stone Bricks when put into use in 12w18a.

Chiseled Sandstone originaly appeared as two unused sprites in Official 1.2.1. The appearance changed when they went into use in 1.2.2. This pack uses a mix of the two sets of sprites for the current chiseled sandstone.

Cobblestone Stairs were titled Stone Stairs until the addition of stone brick stairs in 1.8. The original item icon for stairs were glitched.

Cracked Stone Bricks were named simply Stone Bricks when introduced in 1.8 beta.

Command_block: the original 1.4.2 command block texture is this pack's command_block_front. Since current command_blocks are multi-type and directional, the side textures for all three types are preserved as per 15w34a.

Diamond_block in 0.31 29 January 2010 was originally referred to as emerald (emeralds were originally rubies), but the next day the name was changed to diamond. The tools were only ever diamond, so for clarity, the name diamond is preserved for all.

Dirt, the pre-classic texture is so subtly different from the beta 1.9-pre5 change, only the most observant players would notice, but it's there.

Door sound changed in alpha.

End_stone 1.9-pre3 texture is included, although this texture was never used on the end_stone block once it was finally introduced in beta 1.0.0.

Fire model changed in 1.8 with the sides no longer slightly rotated.

glowstone block texture introduced in 1.2.0 had a border until beta 1.9-pre5

grass used to be bright green without biome specific shades.

grass_path used to simply be gravel blocks, so that is its appearance in this pack.

gravel changed many times. The one used is the original from classic.

Hay Bale was originally named Hay Block in 13w16b.

The hopper item sprite in 13w01a was originally a WIP placeholder.

Lapis_block, after being added in 1.2, was rotated in 1.6. I can't be sure which rotation is the original.

Lava texture was originally static in classic 0.0.12a, and then animated in 0.0.19a.

Leaves of each variety use the original version of that variety, with oak being the 0.0.14a_01 classic, birch and spruce the 1.0 beta, jungle the 1.2.1, and acacia and dark oak being the 1.7.2.

Log first introduced in 0.0.14a_01 classic later became oak log. All logs shared their top texture with oak until 1.7.2.

Mossy Cobblestone was Moss Stone when introduced in Classic 0.26.

Mossy Stone Bricks were named simply Stone Bricks when introduced in 1.8 beta.

Netherrack was originally called Bloodstone in 1.2.0.

Oak Stairs were titled Wood Stairs until the addition of other wood stairs in 12w25a. The original item icon for stairs were glitched.

Observer blocks, from the time they were introduced (without a face) in 1.11 16w39a until 16w43a, the arrow pointed the wrong way (toward the face, not the output).

Peonies (a two-block tall flower) was originally the one-block tall flower paeonies.

Poppies were originally roses. Roses were even at one time cyan but only for pre-release 0.1.0. To commemorate this, 1/4th of all planted roses will be cyan in this pack.

Pumpkins used to have the carved pumpkin face until the actual carved pumpkin was introduced in 1.13.

Sandstone smooth and carved textures were added in 1.2.1, even though these textures were changed in 1.2.4 when the blocks themselves were implemented. They appear in this pack because they are interesting.

Spawners used to have a simpler, lighter-colored texture.

Stairs originally faced left, not right.

Terracotta was originally Stained Clay and Hardened Clay in 1.6.1 until 1.12.

Water in Classic originally had no animation, being added in 0.0.19a.

Wool was originally called cloth in 0.0.20a Classic, with there being two purples and no black. With the name being changed to wool in 1.2, along with the color changes to include dropping the second purple for black.

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### Items
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Armor sprites in the indev versions included studded armors, but they were never used in-game. Cloth (wool) armors were renamed to leather in 1.0.8.

Bed used to just be a red one, until other colors were introduced in 17w15a.

Boat was added in 1.0.6. Crafting boats originally required a wooden shovel, even though the original boat entity had no oars!

Charcoal was added in 1.2 with the same texture as coal, not getting its own texture until 1.6.1 13w19a.

Clock was added in 1.2.0 as two textures, which combined in 1.5, retaining the same appearance in-game.

Coal was added during indev, with its texture updated in the same year. This pack reverts to the original indev texture.

Cod was originally Fish until 17w47a.

Dandelion in was Classic 0.0.20a was known as just Yellow Flower.

Dark Oak was first titled Roofed Oak, referring the the roofed forest biome they occur in.

Emeralds were originally rubies and in 0.31-29Jan2010 diamond_block was originally referred to as emerald, but the next day the emerald block name was changed to diamond. The diamond tools were only ever diamond. Emeralds and rubies are gemologically both chromium-based gem with different color qualities. In this pack, for clarity, the name diamond is preserved for all diamond items, and for old-school flavor the emeralds are reverted to ruby. There never was a corresponding block named ruby ore or block, so the emerald ore and block now carries the gem's longer name as Ruby Emerald for clarity and continuity purposes.

The Enchanted Golden Apple (Notch Apple) crafting recipe is reinstated as it was in v1.3.1, along with its corresponding Achievement "Overpowered" which includes the original dev phrase "Build a Notch Apple" instead of the later "Eat a Notch Apple."

Fire_charge has always looked like a fire charge, but the Ghast's fireball (until Beta 1.9-pre1) used to use the snowball texture in lieu of sharing the fireball texture with the fire_charge.

Gunpowder as introduced in indev 0.31 was Sulfur until 1.3 beta.

Ink Sac as introduced in 1.2 beta was named Ink Sack.

Leather armors in indev were cloth until alpha v1.0.8, and had no undyeable overlays until 12w37a.

Melon Slice was originally called just Melon in beta 1.8.

Mob head items were originally 2D sprites.

Infested blocks (monster egg blocks) were originally called Block 97 in 1.8-pre1, being renamed to their respective stone types in 1.3.1, with the three newest forms (stone brick, cracked stone brick and chiseled stone brick) being added later in 1.7.2.

Nautilus_shell introduced in Bedrock Edition 1.2.20.1 had a different appearance.

Oak Stairs were titled Wood Stairs until the addition of other wood-type stairs in 12w25a. The original item icon for stairs were glitched.

Poppy was originally Rose when introduced in 0.0.20a Classic.

Steak was originally introduced as Cooked Beef in 1.8.

Structure_block void as an item originally used the barrier texture.

Sugar Cane was Reeds when introduced in v1.0.11 alpha.

Wool was originally called cloth in 0.0.20a, with there being two purples and no black. The name changed to wool in 1.2, along with the color changes to include dropping the second purple for black.

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### Entities
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Boat was added in 1.0.6. In 1.9 boat entities were overhauled to add oars, to make them bigger, and to add wood specific textures. The Oak Boat in this pack showcases the original oarless entity look and feel.

Paintings had slighly different textures when first introduced in indev.

Steve's texture originally had a beard in pre-classic rd-132328, the beard being removed in Classic 0.24 because everyone thought it was a smile.

Villagers will be tagged Testificate as they were in the beta 1.9 pre-release.

Zombies used to drop only feathers, because Notch didn't know what they should drop.

The zombie pigman skin is the original skin, openly shared by its creator XaPhobia (PokeAddicted)

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### GUI
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Minecraft didn't always have a food indicator, as food was introduced later. To commemorate this, yet to still allow some indication of the current food level, the food indicator was subtracted except for the occasional appearance of half-food units.

Single-player worlds were originally referred to as Levels.

Splashes are as they appeared in Indev.

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### STRUCTURES
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The original Indev House was a cobble structure containing chests with every possible item and block for testing purposes.

Also included is the second version of the Indev House, made of planks and having no chests.

Obsidian walls used to spawn, presumably to test directions.

A brick pyramid used to spawn, presumably to test the loading of large structures.

Glass pillars used to spawn, at one time to help locate strongholds before eyes of ender were introduced.

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### Sounds
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The original sounds for doors.

The original sounds for hurt.

The original sounds for bows and arrows.

The original lava sounds.

The original water sounds.