How to Construct Cartridge Files For the 2-XL Simulator
Basic Steps for Adding a Tape/Cartridge to the Simulator:
- Create a subdirectory in the carts/ directory for the tape
- Add the name of the subdirectory to the carts/carts.txt file
- In the subdirectory create a jpg file 'front.jpg' with an image of
the cartridge. it should have a size of exactly 500x400 pixels.
- If the cartridge uses a custom button overlay, add a file
'buttonoverlay.jpg' which must have a size of exactly 384x153 pixels.
- If the cartridge has an accompanying booklet, create a html file named
'booklet.html' with the contents of the booklet (this is just a standard
web page, you can link to images in the cartridge directory as normal).
Even if the tape does not come with a booklet, you can still make a
booklet.html page with extra info about the tape.
- Add 4 audio files 'Track1.mp3','Track2.mp3','Track3.mp3','Track4.mp3',
corresponding to the audio tracks from buttons 1-4 from left to right.
see below for more info on creating these audio tracks.
Successfully Creating the Audio Track Files:
- You can use a variety of software to create the 4 audio track files that
the simulator uses; here i describe what i have found is fastest. The
files must be in MP3 format and named 'Track1.mp3','Track2.mp3', 'Track3.mp3','Track4.mp3'.
- The bitrate of the files is not critical *however* i have found that
Macromedia Flash sometimes seems to have a bug where it speeds up mp3
files recorded at too low a bitrate. I have used 64k bps, 16bit, 22khz
mono, but you can experiment with quality and size to find a setting you
are happy with; i suggest you keep a good quality copy of the files in
case you need to edit them later (you can always compress more later).
- Double speed:
Flash can only playback mp3 files with sample rates that are multiples
of 11khz. Most MP3?s are encoded at 44khz and should play back fine in
flash. However if your mp3?s sound speeded up or like they are playing
at double speed, it will probably be because they are encoded at a
different sample rate, such as 16khz. If this occurs you should re-encode
your mp3?s at 44khz.
- I use the Sony (aka SonicFoundry) SoundForge program for recording the
audio files; i just place a small mic near the back of the 2-XL, set
the volume not too loud, and record all 4 tracks, without stopping the
2-XL, once after the other, starting with begining of tape and button 1
pushed, and pushing subsequent buttons each time he says to turn him off.
SoundForge has a nice option to 'drop a marker' during recording, and
I push this button each time i change the button.
3b) After all 4 tracks are recorder, i use SoundForge to create regions
from markers (menu options), and then rename the regions Track1 through
Track4, and extract them with menu command, in .wav format.
- Then i reload the .wav files, and trim the beginings to they they
are all aligned on the start of 2xl speaking.
- Now I have the 4 large audio files in .wav format, *approximately*
aligned. I say approximately because sometimes the speed of playback
on a tape will hit a snag, depending on the condition of your 2XL and
your tapes. The timing speed can slip occassionally; ive had tapes
that require no adjustment, and some that required quite a few fixups.
- The trick is that the tracks must line up at the points where he says "push push xxxx now..." in order for it to switch tracks flawlessly.
- I have found the easiest way for me to fix alignments is to use a
multitrack editing program; I use Sony (SonicFoundry) Acid for this.
I load all 4 tracks in, and either visually examine the alignment,
or jump around playing all 4 simultaneously so that i can hear where
the slips in timing are. Its not hard to see the slips and you
get experienced with seeing them as you work. The ability to play
all tracks simultaneously is the key; any multitrack sound editor
should be able to do this for you.
- The easiest/best way to fix a slip i've found in Acid is to add a split
point in a track where there is some silence, and then drag the slip
leftward over itself; in this way i can splice out small gaps of time
in order to fix alignment issues.
- Once i've fixed any allignment if required, i tell Acid to render all
tracks to separate .wav files.
- When i have all 4 .wav audio files trimmed and aligned, i load them
back into SoundForge, and save them all in .mp3 format (i used 64k bps,
16bit, 22khz mono). I keep backups until i know the files are good.
Become a 2-XL Tape Author(!)
Why not make your own cartridges? Just follow instructions above using a
multitrack sound editor and make your own custom audio tracks and images.
Imagine how difficult it was to plan out the questions and to keep the
audio tracks synchronized in 1978 on mechanical editing equipment.