ooooo, we have to search a giant, tangled jungle of data for the lost City of Antesher - hidden on an ancient magnetic tape full of crazy sounds. But some very fine gentlemen and fellow digital deep-drillers paved the way ahead. Thanks to these vanguards we have the tools and a cryptic treasure map to make this intellectual expedition a success. And this is our plan:
Sounds like a life task? Don't worry companion. It's way easier than it looks thanks to the shoulders we can stay on. If we would have to start from ground up, we would have to connect a cassette-player with our PC and use Dominic Mazzonis Audacity to make the analog screech a digital one. If we wouldn't know what computer the program was written for, we would have to use many emulators, Software that transmogrify modern shiznik, whizz-bang, superfly PCs in 1-MHz-relics from the past! VIC-20, C64, TI-99, Sinclair ZX, CPC 464, Atari 800/XL, MSX, Elan Enterprise, Dragon, Origin, BBC Micro and many more were popular back then. But we know that it's a Sinclair Spectrum file, so no time consuming "trial & error" is required, phew!
But not all spectrum emulators can handle digital soundfiles directly. So we should convert the screech into something else, something convenient and small. Thankfully we can use maketzx from the italian group RamSoft - it produces, as the name suggests, .TZX files (invented by the Slovene Tomaz Kac). These can be easily fastloaded into a emulator like Speccy (by Marat Fayzullin) so we can play this 40 years old work of binary art on a modern PC. But more important for us: we are now able to create a .SNA-file. It's a 1:1 snapshot of the spectrum memory, without any compression. Thus a 48k .SNA file is exactly 49179 bytes long. And somewhere there rests the lost city of Antesher...
One rainy (ok, I make this up) day in late 2000 Tyrone L. Cartwright stumbled upon notes he made while hacking the game ages ago - fortunately, he has put them online:
- Digitize the analog audio
- Find a compatible computer
- Convert the digital audio into software
- Load the file into the ancient computer
- Create a 1:1 copy of the computers memory
- Search this copy for Antesher
- Extract the city-data
- Use software to reconstruct the city in 3D
Sounds like a life task? Don't worry companion. It's way easier than it looks thanks to the shoulders we can stay on. If we would have to start from ground up, we would have to connect a cassette-player with our PC and use Dominic Mazzonis Audacity to make the analog screech a digital one. If we wouldn't know what computer the program was written for, we would have to use many emulators, Software that transmogrify modern shiznik, whizz-bang, superfly PCs in 1-MHz-relics from the past! VIC-20, C64, TI-99, Sinclair ZX, CPC 464, Atari 800/XL, MSX, Elan Enterprise, Dragon, Origin, BBC Micro and many more were popular back then. But we know that it's a Sinclair Spectrum file, so no time consuming "trial & error" is required, phew!
But not all spectrum emulators can handle digital soundfiles directly. So we should convert the screech into something else, something convenient and small. Thankfully we can use maketzx from the italian group RamSoft - it produces, as the name suggests, .TZX files (invented by the Slovene Tomaz Kac). These can be easily fastloaded into a emulator like Speccy (by Marat Fayzullin) so we can play this 40 years old work of binary art on a modern PC. But more important for us: we are now able to create a .SNA-file. It's a 1:1 snapshot of the spectrum memory, without any compression. Thus a 48k .SNA file is exactly 49179 bytes long. And somewhere there rests the lost city of Antesher...
One rainy (ok, I make this up) day in late 2000 Tyrone L. Cartwright stumbled upon notes he made while hacking the game ages ago - fortunately, he has put them online:
"The city is mapped in the upper 16k of memory. Each vertical column is represented by one byte - there are 128x128 columns of city space. The data starts at the left, runs along the top-left wall to the top, then repeats for the next row, until finally the last 128 bytes represent the front wall of the city."
How he got to all this data? Disassembly. A lot of analyzing. And the fact that most games anno 1983 were NOT encrypted for copyright reasons. A disassembler (like Skoolkit for the Sinclair Spectrum, here you find a tutorial) is a program that tries to translate machine language (0 and 1) back into assembly language (to get a quick overview about the differences between assembler, op-code and machine-language have a look at "Nutshells"). And if you are really deep into this, you can reverse engineer a game with a disassembler. Wanna give it a try? You can download the files on Derek Bollis Homepage. Thanks to these fellow adventurers we know that Antesher is located between the Addresses #C000 and #FFFF. Below you see a little snippet of one of those "hex dumps". Marked in yellow: The starting address (C000) and the first pillar in hex: 3F, which is 63 in decimal or 111111 in binary. On the next page you will see what this means...