Codemasters CD - Revision history

NigeNigeNige: Compilation, fix links

2023-02-13T13:19:19Z

Compilation, fix links

Spanner: /* Pictures */

2017-01-17T17:44:17Z

‎Pictures

Fgbrain at 21:47, 6 March 2012

2012-03-06T21:47:43Z

MacDeath at 12:40, 5 January 2011

2011-01-05T12:40:40Z

Nocash: /* Audio Signals */

2010-09-14T21:29:16Z

‎Audio Signals

Nocash: /* Info Fragments on Spectrum CD Games Pack (Code Masters) (1989) */

2010-08-10T21:22:30Z

‎Info Fragments on Spectrum CD Games Pack (Code Masters) (1989)

Nocash at 21:21, 10 August 2010

2010-08-10T21:21:58Z

Nocash: /* Pictures */

2010-08-10T21:09:52Z

‎Pictures

Nocash at 21:06, 10 August 2010

2010-08-10T21:06:03Z

Nocash at 11:29, 10 August 2010

2010-08-10T11:29:42Z

@@ Line 87: / Line 87: @@
 == Links ==
-* http://worldofspectrum.org/ - has a review about the Spectrum version
+* https://worldofspectrum.org/ - has a review about the Spectrum version
-* http://www.olivertwins.com/ - according to this webpage, the Oliver Twins created "The CD Games Pack" in December 1989, for Amstrad CPC, Spectrum, and Commodore 64, published by Codemasters
+* https://www.olivertwins.com/ - according to this webpage, the Oliver Twins created "The CD Games Pack" in December 1989, for Amstrad CPC, Spectrum, and Commodore 64, published by Codemasters
-* http://www.speccy.org/trastero/cosas/JL/CableCD/CableCD.html Rev-engineering the wire of the CD Games Pack for Spectrum.
+* https://www.speccy.org/trastero/cosas/JL/CableCD/CableCD.html Rev-engineering the wire of the CD Games Pack for Spectrum.
-[[Category:Vaporware]][[Category:DATA Storage]]
+[[Category:Compilation]] [[Category:Games]] [[Category:Vaporware]] [[Category:DATA Storage]]

@@ Line 9: / Line 9: @@
 File:CodemastersCDforC64.jpg|Commodore 64 version
 File:NoPicture.gif|Amstrad CPC version
-File:NoPicture.gif|Inside of plug/cable
+File:Inside the adapter.jpg|Inside of plug/cable
 File:OliverTwinsCodemastersCD.gif|Info from http://www.olivertwins.com/
 File:CodemastersCdOriginalCable.jpg|Cable Connectors

@@ Line 13: / Line 13: @@
 File:CodemastersCdOriginalCable.jpg|Cable Connectors
 </gallery>
 == Schematic ==

← Older revision		Revision as of 12:40, 5 January 2011
Line 84:		Line 84:
	* http://www.speccy.org/trastero/cosas/JL/CableCD/CableCD.html Rev-engineering the wire of the CD Games Pack for Spectrum.		* http://www.speccy.org/trastero/cosas/JL/CableCD/CableCD.html Rev-engineering the wire of the CD Games Pack for Spectrum.

−	[[Category:Vaporware]]	+	[[Category:Vaporware]][[Category:DATA Storage]]

@@ Line 37: / Line 37: @@
 == Audio Signals ==
-Below screenshots are showing some interesting sections of the Tracks on a Codemasters CD (screenshots are based WAV files, recorded from the Spectrum version).
+Below screenshots are showing some interesting sections of the Tracks on a Codemasters CD (screenshots are based on WAV files, recorded from the Spectrum version).
 * Theoretically the audio signals should contain perfect '''rectangular waveforms''' - the tested WAV files did contain some '''analog dirt''' (the source of that dirt is unknown, either the original CD was mastered using analog equipment, or the CD-to-WAV conversion was done using analog sound input - or both).

@@ Line 61: / Line 61: @@
 The loader asked the user to choose to use kempston or sinclair joystick interface.
-A dissassembly of the loader reveals the following:
+A dissassembly of the Spectrum loader reveals the following:
 * For kempston: Bit 4 (joystick fire) (pin6 on a atari-style kempston port) of port &1f is data.

@@ Line 1: / Line 1: @@
 The Codemasters CD was a compilation of games from Codemasters which came on a Audio CD, bundled with a special connection cable to connect an Audio CD Player to the Joystick Port. Since the computer can't boot from the Joystick Port, it also included boot software on cassette. The Codemasters CD was announced for ZX Spectrum, Commodore C64, and Amstrad CPC.
-However, only the '''Spectrum''' and '''Commodore''' versions seem to have been actually released. According to the Oliver Twins (the makers of the CD), the '''Amstrad CPC''' hardware did exist, too. Though this seems to have been only an unreleased prototype.
+The '''Spectrum''' and '''Commodore''' versions have been actually released, but - as far as known - the Amstrad version wasn't ever released. According to the Oliver Twins (the makers of the CD), the '''Amstrad CPC''' hardware did exist, too. Though this seems to have been an unreleased prototype.
 == Schematic ==
@@ Line 19: / Line 30: @@
                                          |\
                                          | C---------- Joystick.Pin6 (Fire)
-The above circuit was rev-engineered by measuring the resistance between the cable pins, but without opening (=destroying) the moulded plastic connector that houses the original circuit - so far, it isn't fully confirmed if the original cable does really contain the above components (not to mention multimeter tests can't reveal any additional small capacitors).
+The above circuit was rev-engineered by measuring the resistance between the cable pins, but without opening (=destroying) the moulded plastic connector that houses the original circuit - so far, it isn't fully confirmed if the original cable does really contain the above components (not to mention that multimeter tests can't reveal any additional small capacitors).
 The material of the connector is still unknown, but if it's soft/elastic then it should be extremly easy to peal off the plastic with a knife and pincers, for revealing what is really in there.
-'''You are welcome to add your own results here if like to combine research with some minor destruction!'''
+'''You are welcome to add your own results here if you like to combine research with some minor destruction!'''
 == Audio Signals ==
@@ Line 52: / Line 63: @@
 A dissassembly of the loader reveals the following:
-For kempston:
+* For kempston: Bit 4 (joystick fire) (pin6 on a atari-style kempston port) of port &1f is data.
-Bit 4 (joystick fire) of port &1f is data.
+* For sinclair: Bit 1 (joystick right/key '2') (pin6 on amstrad's non-atari-style spectrum +2 joystick port) of port &f7fe is data.
-For sinclair:
+The loader is patched according to the interface chosen and appears to be a modified version of the normal cassette loading functions in the Spectrum BIOS.
-Bit 1 (joystick right/key '2') of port &f7fe is data.
+The CD capacity is said to be "12 Megs" (presumably meaning 12 Megabit = 60 tracks with 25Kbytes each).
-The loader is patched according to the interface chosen and appears to be a modified Spectrum ROM loader.
+It is quite probable that the Amstrad loader is similar to the Spectrum loader:
-It seems to load the standard tape data structure: pilot, sync byte, data bytes and checksum byte.
-−
-The cable is most likely to be mono, because only 1-bit is used for loading.
-−
-No info if/how the stereo signal is used. The cable does reportedly contain a 1bit A/D converter, which is probably a single transistor or so (so it's mono, not stereo?). The CD capacity is said to be "12 Megs" (presumably meaning 12 Megabit = 60 tracks with 25Kbytes each).
-−
-It is more probable that the Amstrad loader is similar to the Spectrum loader:
 . The CPC has same CPU as the Spectrum
 . The CPC already has a number of loaders based directly on the Spectrum ROM loader, so a conversion of this loader to CPC would be easy.
@@ Line 73: / Line 78: @@
 == Links ==
-* http://www.kjthacker.f2s.com/docs/audiocd2.html - DIY - '''caution:''' the disclaimer on that webpage says that it is '''not''' based on the real Codemasters CD - so it may be totally incompatible to the original Codemasters CD - also, Kevin has confirmed that it's an '''untested''' and '''unfinished''' DIY project
+* http://worldofspectrum.org/ - has a review about the Spectrum version
-−
-* http://worldofspectrum.org/ - has a review about the Spectrum version - which conflicts with the DIY info (the Spectrum review implies it contains a mono 1-bit A/D converter, not a stereo connection without A/D converter) (the A/D converter - if it does exist - might refer to something simple, like a transistor)
 * http://www.olivertwins.com/ - according to this webpage, the Oliver Twins created "The CD Games Pack" in December 1989, for Amstrad CPC, Spectrum, and Commodore 64, published by Codemasters
-* http://www.speccy.org/trastero/cosas/JL/CableCD/CableCD.html Testing the wire of the CD Games Pack for Spectrum.
+* http://www.speccy.org/trastero/cosas/JL/CableCD/CableCD.html Rev-engineering the wire of the CD Games Pack for Spectrum.
-−
-Whether or not the Amstrad CPC version was actually released is a bit unclear. Did anybody ever see it for real?
-−
-== Pictures ==
-−
-<gallery>
-File:TheCdGamesPackForSpectrum128.jpg|Spectrum 128 version
-File:CodemastersCDforC64.jpg|Commodore 64 version
-File:NoPicture.gif|Amstrad CPC version
-File:NoPicture.gif|Inside of plug/cable
-File:OliverTwinsCodemastersCD.gif|Info from http://www.olivertwins.com/
-File:CodemastersCdOriginalCable.jpg|Cable Connectors
-</gallery>
-−
 [[Category:Vaporware]]

@@ Line 19: / Line 19: @@
                                          |\
                                          | C---------- Joystick.Pin6 (Fire)
-The above circuit was rev-engineered by measuring the resistance between the cable pins, but without opening (=destroying) the moulded plastic connector that houses the original circuit - so far, it isn't fully confirmed if the original cable does really contain the above components.
+The above circuit was rev-engineered by measuring the resistance between the cable pins, but without opening (=destroying) the moulded plastic connector that houses the original circuit - so far, it isn't fully confirmed if the original cable does really contain the above components (not to mention multimeter tests can't reveal any additional small capacitors).
 == Info Fragments on Spectrum CD Games Pack (Code Masters) (1989) ==

← Older revision		Revision as of 11:29, 10 August 2010
Line 2:		Line 2:

	However, only the '''Spectrum''' and '''Commodore''' versions seem to have been actually released. According to the Oliver Twins (the makers of the CD), the '''Amstrad CPC''' hardware did exist, too. Though this seems to have been only an unreleased prototype.		However, only the '''Spectrum''' and '''Commodore''' versions seem to have been actually released. According to the Oliver Twins (the makers of the CD), the '''Amstrad CPC''' hardware did exist, too. Though this seems to have been only an unreleased prototype.
		+
		+	== Schematic ==
		+
		+	José Leandro Novellón did some reverse engineering on the Spectrum cable in 2008. The results were released on http://www.speccy.org/trastero/cosas/JL/CableCD/CableCD.html (spanish). According that results, the cable is '''assumed''' to contain hardware like this:
		+	\| C---------- Joystick.Pin1 (Up)
		+	\|/
		+	Audio Left (Tip) ------o----[330]----B\| BC549B
		+	\| \|\
		+	[1K] \| E--+
		+	\| \|
		+	Audio Gnd (Base) ------o----[470]----------o------- Joystick Pin8 (Common)
		+	\| \|
		+	[1K] \| E--+
		+	\| \|/
		+	Audio Right (Mid)------o----[330]----B\| BC549B
		+	\|\
		+	\| C---------- Joystick.Pin6 (Fire)
		+	The above circuit was rev-engineered by measuring the resistance between the cable pins, but without opening (=destroying) the moulded plastic connector that houses the original circuit - so far, it isn't fully confirmed if the original cable does really contain the above components.

	== Info Fragments on Spectrum CD Games Pack (Code Masters) (1989) ==		== Info Fragments on Spectrum CD Games Pack (Code Masters) (1989) ==