Codemasters cd games pack

I can pass them onto my grandkids. The CD contains games which were out on tape already, but loaded in quite fast, so why bother to archive? The tape was only the loader. Thus, I am still no nearer knowing why they loaded through the joystick port.

As for how many were sold, I have no idea. I got mine as a review copy from the Codies Brian the tightwad. I asked them how the information was "recorded" onto the CD. It is recorded as a stereo audio signal. One channel has a clock pulse signal, the other channel has the data signal.

The clock pulse is used to extract the data. Using this method they could load software much faster and more reliably. I think the lead was made for the joystick port for two reasons: 1. At one point, when I had some time, I was going to attempt to make my own cd in the same way, but without using any of their work.

I haven't got around to doing that yet. Regards, Kev. It'll probably compress down to only a few meg, I should think. The CSW format can store these tracks, as it's already been prooved with a popular modified spectrum emulator can't say which one ;- I've been told that the speed is about the fastest that can be stored on a CD. They examiners were amazed with the speed. I think it was possible to make a TZX, but we'd need a modified decoder to get it into that format. Only a custom port could take the speed of the data.

The EAR socket was not up to it. Hence the special interface ;-. Quite so. Once loaded it allowed you to choose from either Kempston or Sinclair joystick options, and then prompted you to connect the CD lead to the joystick port on your chosen interface. You were then given an option to enter a test screen to allow you to adjust the volume level on the CD player to an optimum level, and once complete start loading some games.

Since CD audio has a very defined and absolute bit rate 44, samples per second , unlike cassette tape, it is possible to reduce the delay loops in the loader software that would normally allow for variations in cassette speed, allowing for a significant increase in the loader speed. The core of the system is actually a hacked about version of the Spectrum ROM loader, with delay loops removed and the loader modified to read the joystick port instead of the EAR port on the ULA.

To achieve a clean square wave signal from the CD audio, the cable contains a simple circuit designed to boost the signal and alter the input to the interface to TTL levels acceptable to the joystick interface. As the signal is routed through the joystick port and not the usual EAR socket, there is consequently no loading noise! The cable was reverse engineered a while back by some CPCWiki users, and found to contain 5 resistors and 2 transistors. In hindsight I think we made some mistakes, for example by assuming that 30 games would have a very strong appeal e.

Also, the new hybrid technology which was a stepping stone between cassette loading and CD ROM drives, was hard to communicate clearly and seemed to have less appeal than we anticipated.

The leads for the C64 and Spectrum are compatible. My mates and i were all tape users, so a disk drive, was way out of our price range, let alone a CD player. Think codemasters might have been a little too far ahead of the game for the market they were after.