Brick House

by sealldev
๐Ÿšฉ CTFs DawgCTF 2025 misc
Brick House / DawgCTF 2025
Brick House

Description

I was going through some old tapes from the '80s and came across a strange recording on one labeled "Basic Programs #1." Any idea what it might be?

Beginning the challenge, all we are given is a MysteryTape.wav.

What is this?

The challenge description mentions the 80s and โ€˜Basic Programs #1.โ€™, letโ€™s see if we can identify what that might be!

Considering itโ€™s the 80s, it is probably talking about some older computers that used tape. From a quick search these include the Commodore 64, Apple II and BBC Micro. I decided to pursue the Commodore 64 just because a lecturer had talked about it before :p (you know who you areโ€ฆ)

The next step became, how can we emulate this?

Emulation

The first result is the Emulation Wiki where it suggests the โ€˜VICEโ€™ emulator.

After installing VICE from SourceForge (I used the GTK3 version), the application boots with a delightfully dated UI: ui

Using the controls down the bottom, we can load tapes: tapeload.png

I try to load the MysteryTape.wav, but it doesnโ€™t workโ€ฆ

Converting to tap

With some research, I find VICE and most other emulators seem to use .tap files for tapes. A program to convert a WAV to TAP is WAV-PRG.

Opening the program, we are met with another delightfully ancient UI: anotherui.png

I press โ€˜Create a TAP fileโ€™ and then โ€˜from an audio file (WAV or similar)โ€™ and then โ€˜OKโ€™. Then I select the MysteryTape.wav.

After that, we get a MysteryTap.wav!

Emulation (again)

I attach the MysteryTap.tap with the โ€˜Autostartโ€™ option and press Play.

flag.png

Flag: DawgCTF{B4CK_70_B451C5}

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