Posts for DavidN


Experienced Forum User
Joined: 7/4/2018
Posts: 3
Just wanted to come back and say that I eventually finished this! Final time for Prince of Persia DOS is 12:20.58 measured from the first frame of the game to exiting the final room (here, I'm counting a documented feature that allows you to skip to level 4 in "practice mode" as a legitimate part of the game). https://www.youtube.com/watch?v=vIjM2Sy7pOo - Raw output https://www.youtube.com/watch?v=hfOocUkxJ08 - With breathless commentary Thanks for everyone's pointers - I'm already seeing bits of the video that could be done better for a second version...
Experienced Forum User
Joined: 7/4/2018
Posts: 3
Aha, thank you so much - I can't believe it didn't occur to me to just press the cursor keys :) I think I was thrown by having no reaction from the onscreen keyboard until advancing to the next frame, and the way that the keys act like a toggle instead of keyup/keydown on press and release. And those pieces of advice really sped me up to the point where I was able to piece together a complete run of the fourth level. (At the beginning I use Shift+L which enters a practice mode up to level 4 and reduces your timer to 15 minutes - it's intended to make the game impossible to complete.) https://www.youtube.com/watch?v=Tvm1CRAj_IM It's odd instructing a computer on how to play a game rather than directly doing it yourself - you lose a lot of the feel of the controls and timing, so I was surprised that some parts actually felt more difficult than they would have been if I were doing a human speedrun. But it definitely let me try some guard-skipping tricks that I wouldn't have risked if I were doing it manually.
Post subject: First TAS, learning JPC-RR (Prince of Persia)
Experienced Forum User
Joined: 7/4/2018
Posts: 3
Hi, TAS community! DosGameClub[.com] is looking at the original Prince of Persia this month - I've been vaguely interested in speedrunning for a while, but have decided to take the chance to record one myself for the first time. I've read around the instructions on JPC-RR and have got some great hints from DungeonFacts' thread on Crystal Caves and c-square's advice. I've been able to get the game up and running in the mouse-JPC-RR fork and have even recorded a brief test video which involved loading saved states and re-recording: https://www.youtube.com/watch?v=9uhxvbgGMIY The way I understand it - is this all correct? - A "movie" in TAS terms is not a video file like it sounds, but a list of recorded keyups/keydowns/etc that you piece together using a TAS-appropriate emulator. - The emulator records these key inputs as you play or step through the game, and you can "rewind" to a previously saved state at any time and re-record from there. - To get the final TAS, you set the emulator going and play back the movie (i.e. set of keypresses), dumping the screen output to disk to eventually transform into a video file. So I think I'm on my way, though there are a couple of things I'm unsure about: - Can you alter the amount of time in ticks/ms that pressing F will skip forward? Prince of Persia runs at ~12fps, and hitting F five times per frame is beginning to give me RSI :) - Giving input to the game as I step through seems to be a rather cumbersome process of switching focus to the onscreen keyboard, pressing the key down, making sure the emulator window is focused again and hitting F to advance. Is there a faster way - perhaps by sending a frame-advance signal to the emulator without the window having to be focused? - Is there a way to step backwards or do I have to just be more careful about when I choose to save state? :) Thanks for any and all advice!