Submission #2036: upthorn, nitsuja's SegaCD Sonic the Hedgehog CD in 18:04.75

Console Sega CD Emulator GENS
Game Version USA Frame Count 65085
ROM Filename Sonic CD (U).iso Frame Rate 60
Branch Rerecord Count 12858
Unknown Authors upthorn, nitsuja
Game Sonic the Hedgehog CD
Submitted by upthorn on 7/24/2008 4:36:47 AM

Submission Comments
The inaugural TAS for new Sega CD rerecording.

Emulator settings:

  • Emulator used: Gens 10 + SCDCamhack + Speedometer + SolidityViewer + (partial)HitboxDisplay
  • Bios used: scd_110_us.bin
  • Allow Up+Down: Yes
  • Sound: Enabled, 44100KhZ
  • Perfect SegaCD Synchro: Enabled
  • Options: Sega CD SRAM Size = 64 KB.

Something Awful members

I notice that people have posted links to this in both the Sonic 06 LP thread, and Cybershell's SONIC series LP thread, so I should like to explain myself. Basically, the idea I had here was "Hey, pokecapn, kungfujesus, medibot. I know you've watched some of my stuff. I watch your stuff, too. How about you drop by and say hi to the nice TASvideos forum users?" No disrespect was meant to IlluminatusVespucci. I simply do not know if he watches and/or cares about TASes at all. For that matter, no disrespect was meant to pokecapn, KFJ, or medibot. This was like a shout out, but more differenter. --Upthorn

Game objectives

  • Ignores delays caused by bonus effects
  • Aims for fastest (primarily in-game) time
  • Takes Damage to save time
  • Abuses programming errors
  • Ignores Semi-important goals in the game
  • Does not fuck with time.
  • Beats Amy Rose.
  • Breaks a bottle of wine on Gens10
  • Colors a read light
  • Calls out Pokecapn, KungFuJesus, and Medibot
  • also maybe illuminatusvespucci I guess


Though primarily played by Upthorn, Palmtree Panic 1 and Collision Chaos 1 are frame-for-frame exact copies of GMVs that were provided by nitsuja.
This GMV uses the Sega CD version 1 US bios, scd_110_us.bin (aka us_scd1_9210.bin). If you wish to use the sega CD version 2 US bios (scd2_200_us.bin or us_scd2_9306.bin), then get instead.
For those of you who prefer the Japanese soundtrack, you have two options, one is to download and use the version 1 Japanese bios. The other is to use ISO+MP3 and replace the mp3s however you see fit. Note that the Japanese gmv is 4 ingame frames slower due to version differences in lag-handling.
If you wish to watch on the PAL version, you are out of luck at the moment, as my attempts to hexedit around the lag differences were slow, frustrating, and unsuccessful.

Stage by stage comments

Tidal Tempest, Act 1

This is the only stage where my time does not beat or match the TSC record. The reason for this is because the TSC records are recorded in Time Attack mode, where none of the timezone posts are present, and having to slow down in order to get rid of a Future post causes me to lose a fair few frames, as I can't jump to fall faster on the cliff just after this.

Comparison Table

Zone TAS Time TSC record Savings Total Savings Total Savings (frame estimate) Notes
Palmtree Panic 1 0'21"01 0'21"65 0'00"64 0'00"64 38 Some time saved here by doing a speedshoe-peelout just before the high jump.
Palmtree Panic 2 0'16"80 0'16"83 0'00"03 0'00"67 40
Palmtree Panic 3 0'17"88 0'17"98 0'00"10 0'00"77 46
Collision Chaos 1 0'15"83 0'20"58 0'04"75 0'05"52 331 A new trick Nitsuja discovered using up+down results in an even faster strategy than my previous discovery.
Collision Chaos 2 0'24"31 0'24"80 0'00"49 0'06"01 361 Full power speed-shoe peelout and a slight route modification save about half a second.
Collision Chaos 3 0'03"35 0'03"35 0'00"00 0'06"01 361 Sprintgod is insane.
Tidal Tempest 1 0'22"65 0'22"58 -0'00"07 0'05"94 357 See above Tidal Tempest 1 comment.
Tidal Tempest 2 0'40"61 0'41"51 0'00"90 0'06"84 411 I think some of the savings come from the "move while charging peel-out" glitch I use here.
Tidal Tempest 3 0'30"13 0'39"00 0'08"87 0'15"71 943 A lot of time savings from the "charge peelout through wall" glitch I use here.
Quartz Quadrant 1 0'19"55 0'20"78 0'01"23 0'16"94 1016 You know, it's not like I've been keeping the increased peelout speed during speedshoes a secret
Quartz Quadrant 2 0'18"86 0'22"36 0'03"50 0'20"44 1226 So I wonder why none of the TSC times outside Collision Chaos 1 make use of it.
Quartz Quadrant 3 0'52"06 0'52"95 0'00"89 0'21"33 1280 I hate the QQ boss...
Wacky Workbench 1 0'25"38 0'26"75 0'01"37 0'22"70 1362 Fuck wacky workbench and it's bouncy floor.
Wacky Workbench 2 0'29"48 0'29"50 0'00"02 0'22"72 1363 If not for the future signpost, I'd have a 28"96...
Wacky Workbench 3 1'04"90 1'06"55 0'01"65 0'24"37 1462 Going through the wall is faster than going around it.
Stardust Speedway 1 0'15"08 0'17"11 0'02"03 0'26"40 1584 This is the best area in the game. Speedy as hell, branching paths all over the place...
Stardust Speedway 2 0'18"66 0'20"20 0'01"64 0'27"94 1676 Nitsuja found a nice trick with in the tubes at the end.
Stardust Speedway 3 1'05"80 1'06"10 0'00"30 0'28"24 1694 If only I could TAS for Metal Sonic, too...
Metallic Madness 1 0'20"58 0'20"83 0'00"25 0'28"49 1709
Metallic Madness 2 0'26"58 0'27"85 0'01"27 0'29"76 1786
Metallic Madness 3 1'09"40 1'18"55 0'09"15 0'38"91 2335 Again, going through the wall is faster than going around
Total 10'18"90 10'57"81 0'38"91 0'38"91 2335

Possible improvements

In-game: If one were not to slow down in order to prevent time travel, the in-game timer on two levels would be improved.
Real-time: I did not do much route testing outside of watching the record TSC videos and duplicating them with frame perfection, so it's possible that there are faster routes yet undiscovered. Perhaps there is a faster way to deal with the quartz quadrant boss...
I am not aware of any other improvements.

Additional notes:

Medibot, I am calling you out!

I see and/or hear you making TAS references on those Sonic 2006 LP videos. Clearly you are aware of this site. Now I challenge you to make your presence here seen.
Also pokecapn, and kungfujesus. And IlluminatusVespucci I guess (I am not sure if he is really down with the TAS thing).

Desync issues

Check and make sure that you have 34 mp3s in the same directory as your ISO. They should be labelled as follows
xxxxxx 02.mp3
xxxxxx 35.mp3
where xxxxxx.iso is the name of your sonic CD ISO file.
If you are missing any mp3, you should be able to fix the desync by copying ANY valid mp3 to the directory of your Sonic CD ISO, and renaming it to the missing filename.

adelikat: Accepting for publication. Also, encoding underway.

Last Edited by upthorn on 7/29/2008 8:52 AM
Page History Latest diff List Referrers