Author Topic: TAP file draft  (Read 2069 times)

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Offline antoniovillena

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TAP file draft
« on: 21:45, 26 April 11 »
  Hello

  I am new in this forum, this is my first message. I am developping a new javascript emulator for CPC machines, like cpcbox. By now the DSK format is not emulated, so the only way to load games is by tape files or snapshots.

  But I have problems with CDT files, I want to load them in a quick way, but my method is very slow because I emulate every cycle. So I have ported the TAP files from spectrum. That files only works in games that use the standard ROM load routine, but I can decide to load in real time or by trapping the ROM routine (very fast way).

  In this link I wrote a draft of the format that I use:
http://roland.antoniovillena.es/taps/tap_file_draft.txt

  Please send me corrections, my english is very bad. I have use the spectrum .tap specification document as start. By now, only I have generated 332 tap files:
http://roland.antoniovillena.es/taps/compilation

  Three of them are unprotected by me with a simple method:
http://roland.antoniovillena.es/taps

  Suggestions are welcomed


  Regards

Offline Gryzor

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Re: TAP file draft
« Reply #1 on: 09:54, 27 April 11 »
Hmm... I really don't know anything about the technicalities of the CDT, but if this format has all the CDT's advantages PLUS fast loading it could be good :)

Offline antoniovillena

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Re: TAP file draft
« Reply #2 on: 15:17, 27 April 11 »
  Hello Gryzor

  It has advantages over CDT, but CDT also have other advantages.

  -You can convert every file from TAP to CDT, but only a small part of CDT files can be converted automatically to TAP. This is because TAP only supports ROM loader routine, and major part of comercial games use custom loading routines (Speedlock, Spectrum,...)

  -CDT files are better in the point of view of preservation. The best format for preservation is a WAV file, so in terms accuracy/storage CDT files offer the best comprise.

  -In terms of software usability TAP files are better. For a tool (for example an assembler) it's easy to generate. And for an emulator, also is easy to load. Less work for the emulator programmer, and also for the user. He can load a TAP file instantly, a CDT depends on Z80 emulation. If your emulator runs CPU 10x faster, the game can be loaded 10 times better than in real time.