1) Distance will be about 8 feet - depending on the zoom capability of the projector optics - you should be fine in an average room.
2) Get yourself a screen - Sony do a good one thats about 150 UKP over here. A good screen will double the reflected light.
3) Get a projector that can run in 'eco' modes, so that when you don't need the high light levels you can run the bulb cooler and extend its life. Personally I rate the NEC VT45(us) VT45G(uk) - try and get a demo of this
Sorry - not true - as 2 minutes on Google will show.
I know of a damn good NEC budget projector (VT45G) with optical shift lens (allows you to correct from off axis picture distoration both horizontal and vertical) for 1,600 UKP at Dabs The US version (VT45) is available for 1,600 USD at LA Computer Center
Other points
1) 800x600 excedes most TV standards and is the resolution of most budget projectors
2) Picture quality due to hardware is more dependant on the optical path and the amount of 'dark space' around the pixels
3) This is worth doing if you have the spare kit lying around, or can pick it up on ebay / computer fairs, otherwise get yourself a decent budget projector
No I don't work for NEC - but I'm really impressed with this bit of kit!
MacroVision works by putting false sync and colour burst signals into the interlaced fields in a composite video signal.
This fools AGC (Automatic Gain Control) circuits into thinking they have a very bright picture, and so they reduce the gain. By varying the signal you can make the picture brightness pulse, or in some cases cause it to loose track of the synchronisation all together.
Conventional display devices don't have to have such accurate control of the gain of the signal, so are not very heavily effected, although it is possible to see the effects on some devices. You could see the high amplitude bursts, but these occur in the 'off screen' section of the field that holds the sync signals, and stuff like teletext - if you have vertical hold then you might be able to see them.
(For a great technical and non-technical explanation check Repair FAQ for an easy explanation check How Stuf Works)
Now originally this was intended to specifically block VHS style recorders, but as things have developed there is another device now in common use that can be effected, that wasn't around in consumer products when MacroVision was invented - the frame store.
These are handy digital devices that read the composite video signal in and store it in real time. The video can then be read out in any format you want. Why would you want to do this?
1) Stabilise the signal
2) Change video formats from 50/60 interlaced fields.
Now the first one is done during video editing so that different sources can be synchronised and things like picture in picture and wipe effects between 2 video sources will actually work. They are also now common in good prosumer VCR's for this reason. Digital camcorders have them by default because of point 2...
The second point is that it allows you to do standards conversion in real time - such as in a capture card where you digitise the signal to a different frame rate.
And here is the point - digital projectors such as LCD and DLP tend to use progressive scan rather than interlaced signals, so they contain conversion technology including frame stores to do the de-interlacing (good notes at SourceForge)
So any device that uses a frame store approach can be effected by MacroVision, it just depends on how good the AGC in the framestore is.
How do you avoid this? Simple really don't use a video signal that can have MacroVision on it. If you have RGB (component) then this won't have protection, and is the superior connection anyway for a projector. The S-Video source is normally ok as it seperates the chrominance and luminancne (colour and brightness) signals - although I've heard of a new 'level 2' MacroVision that can disrupt this - sorry no tech details on that I'm still looking, but I think it has to do with messing about with the chrominance.
Of course the fact you regenerate the signal from the framestore means a good one is able to strip the MacroVision out, but there are cheaper ways to do that, and no I'm not giving the links - spend 2 minutes on Google, and remember that MacroVision is specific to PAL/NTSC so don't go ordering abroad! A good legal reason to have such a device is to connect a non AV socket TV to a non RF output player via a normal VCR, or to connect a projector sensitive to MacroVision when you don't have RGB Component output. Of course in the US you will fall foul of the DMCA, but we already know what a mess that is!
Just to reinforce the previous comment I've personally seen a 36 drive 160GB raid array running stock RedHat 7.2
So I think this means the kernel supports 160 drives.
It was built as a large data store for Astronomical Data and provides around 5 terrabytes usable, cost around 15,000UKP. It runs an XFS file system because 1) SGI has used it for a while and its stable and has a track record, unlike ReiserFS or EXT3 (Not that I make judgements on this, but if you are going to commit expensive data to the disks you want to be sure. 2) It serves an environment of large SGI Origin machines and so integrates seemlessly.
For the techies:
- 36 160GB EIDE Maxtor Units in hot swap carriers for the array - 1 80GB EIDE Maxtor Unit for boot and host drive - one EIDE CDrom. (No Floppy:) - Twin Athlon DDR motherboard heavy on RAM - Twin Gigabit Ethernet cards into local backbone switch. - 4 3Ware EIDE hardware raid cards.[www.3ware.com]
Config - The 3Ware cards provide a SCSI host adabpter to the OS, so they look like a single SCSI drive once they are configured.
The CDrom and Boot/Host drive are on the Mothboard normal EIDE channels.
Each 3ware card has eight drives in a Raid 5 configuration, each drive with a private EIDE channel (no slave drives here)
The 4 3ware cards are then software raided as 4 SCSI devices.
The array itself is split logically into volumes to make it easier to manage.
By all accounts the biggest problem was threading 38 individual EIDE cables through the server case, and finding power supplies big enough to keep the disks and fans spinning.
So this is possible right now, I've seen it from stock parts, it took around a working week to build (hardware and software) and it kicks butt:)
Your argument is sound, and presumably arguable, up to your last step.
Whilst only one copy of your CD, be that the physical CD, a copy on your workstation, or a remote streaming server, is playing you are on safe ground - even if it was techincally infringing they would have a hard time prosecuting as they are all equivalent to just listening to the CD - which was not infringing last time I looked!
As soon as you have 2 copies playing you are in trouble as you have 'duplicated' the CD. This may be you listening on your worksation, whilst your daughter listens to the CD at home, or sharing your MP3's to 3 collegues. This is in no way equivalent to just playing one CD.
If you wanted to do this complying with the spirit of the law if not the letter you would need to have a streaming server that would only play back the tracks on _that_ cd to one person at a time.
This is the same problem MP3.com had when it tried to provide a service where you could upload personal MP3's so you could access them anywhere over the net - thier mistake was to do a good technical implementation whereby server space was preserved by only storing the MP3's once. So when I uploaded "N'Sync Greatest Hits"[1] and was the 453rd person to do so it wouldn't create any extra files, only allow me access to already stored ones. This allowed RIAA et al to succesfully argue that many people were listening to the same CD. If every user had a private area a more spirited defence could have been put up, even if the server storage space went through the roof!
[1] I'm kidding okay - any half decent service would refuse the upload:)
If I play a CD I purchased at home with some friends over, does that constitute a 'public performance'?
IANAL and this is from a UK perspective:
The test for it to be a public performance is that the general public must have access.
So in a physical form, the general public would have to have access to the area the music was being played.
Hence in a shop it is a public performance as the public have access to the shop, but in your home it is not as the public do not have access, only people you invite in.
This is also why you and your friends can watch a video, but a club can't without paying extra fees.
True story - a friend was running a CyberCafe and wanted to be able to stream music to each workstation, so the customers could just select some music on headphones that they liked, rather than playing something on the HiFi. To do this he tried to get a licence to do it properly - but gave up as the licensing authorities in the UK couldn't classify what sort of license he needed! This was about 4 years ago.
I believe the hulls are actually more traditional GRP composites, its just that usually when a boat reaches around 50 foot long you normally build in steel because whilst GRP and similar is great for small light hulls, it gets progressively more difficult to fabricate as the size goes up.
The UK Navy minesweeper fleet was nick named the Tupperware Fleet - Presumably RubberMaid Fleet elsewhere!
Ferrocement Hulls (to give them thier proper name) were reasonably common for 'home build'. You form the hull using a matrix of steel rods and then usually 'spray' the concrete into this matrix, effectively giving you a cast reinforced concrete hull. Whilst these are strong, they are bulkier than steel hulls and can shatter/crack in impacts where steel would just bend or split. These sort of hulls can be quite large, and the concrete sets into a single very strong monocoque structure.
Whilst ferocement hulls do sound wierd, heavier than water steel hulls still work - what is important is that the hull wieghs less than the volume of the water it displaces (Archemedies Principal)
What is wierd is 'floating concrete' that looks like a fine matrix breeze(UK)/cinder(US) building block, but floats because it is mainly air - freaky when you pick the block up and it weighs so little!!!
Slashdot Mirror
1) Distance will be about 8 feet - depending on the zoom capability of the projector optics - you should be fine in an average room.
2) Get yourself a screen - Sony do a good one thats about 150 UKP over here. A good screen will double the reflected light.
3) Get a projector that can run in 'eco' modes, so that when you don't need the high light levels you can run the bulb cooler and extend its life. Personally I rate the NEC VT45(us) VT45G(uk) - try and get a demo of this
Sorry - not true - as 2 minutes on Google will show.
I know of a damn good NEC budget projector (VT45G) with optical shift lens (allows you to correct from off axis picture distoration both horizontal and vertical) for 1,600 UKP at Dabs The US version (VT45) is available for 1,600 USD at LA Computer Center
Other points
1) 800x600 excedes most TV standards and is the resolution of most budget projectors
2) Picture quality due to hardware is more dependant on the optical path and the amount of 'dark space' around the pixels
3) This is worth doing if you have the spare kit lying around, or can pick it up on ebay / computer fairs, otherwise get yourself a decent budget projector
No I don't work for NEC - but I'm really impressed with this bit of kit!
MacroVision works by putting false sync and colour burst signals into the interlaced fields in a composite video signal.
This fools AGC (Automatic Gain Control) circuits into thinking they have a very bright picture, and so they reduce the gain. By varying the signal you can make the picture brightness pulse, or in some cases cause it to loose track of the synchronisation all together.
Conventional display devices don't have to have such accurate control of the gain of the signal, so are not very heavily effected, although it is possible to see the effects on some devices. You could see the high amplitude bursts, but these occur in the 'off screen' section of the field that holds the sync signals, and stuff like teletext - if you have vertical hold then you might be able to see them.
(For a great technical and non-technical explanation check Repair FAQ for an easy explanation check How Stuf Works)
Now originally this was intended to specifically block VHS style recorders, but as things have developed there is another device now in common use that can be effected, that wasn't around in consumer products when MacroVision was invented - the frame store.
These are handy digital devices that read the composite video signal in and store it in real time. The video can then be read out in any format you want. Why would you want to do this?
1) Stabilise the signal
2) Change video formats from 50/60 interlaced fields.
Now the first one is done during video editing so that different sources can be synchronised and things like picture in picture and wipe effects between 2 video sources will actually work. They are also now common in good prosumer VCR's for this reason. Digital camcorders have them by default because of point 2...
The second point is that it allows you to do standards conversion in real time - such as in a capture card where you digitise the signal to a different frame rate.
And here is the point - digital projectors such as LCD and DLP tend to use progressive scan rather than interlaced signals, so they contain conversion technology including frame stores to do the de-interlacing (good notes at SourceForge)
So any device that uses a frame store approach can be effected by MacroVision, it just depends on how good the AGC in the framestore is.
How do you avoid this? Simple really don't use a video signal that can have MacroVision on it. If you have RGB (component) then this won't have protection, and is the superior connection anyway for a projector. The S-Video source is normally ok as it seperates the chrominance and luminancne (colour and brightness) signals - although I've heard of a new 'level 2' MacroVision that can disrupt this - sorry no tech details on that I'm still looking, but I think it has to do with messing about with the chrominance.
Of course the fact you regenerate the signal from the framestore means a good one is able to strip the MacroVision out, but there are cheaper ways to do that, and no I'm not giving the links - spend 2 minutes on Google, and remember that MacroVision is specific to PAL/NTSC so don't go ordering abroad! A good legal reason to have such a device is to connect a non AV socket TV to a non RF output player via a normal VCR, or to connect a projector sensitive to MacroVision when you don't have RGB Component output. Of course in the US you will fall foul of the DMCA, but we already know what a mess that is!
Again, apologies for not repeating the slashbot "party line," but I guess I will just have to take a chance with the karma.
Repeat 10 times before pressing the Submit button.
Slashdot is read by many geeks - I must spend 2 mintues checking my facts with Google before posting.
This, you may find, prevents the egg-on-face problem that makes it look like you have no idea what you're talking about.
Frankly your in depth knowledge of the key players and key designs of the GNU/Linux environment astonishes me.
Seems to me its not just Corporate America that doesn't get it
Perhaps it is the "Smoot"-ing of the Harvard Bridge [mit.edu] you refer to? It's only off by 2 letters...
:)
Amazing - you'd think that at MIT they would know that the way to spell 1 is 'one', not 'on'.
Or am I missing some insightful art point?
I've really yet to meet someone who tries to get everything for free /. thne?
Not spent much time on
Just to reinforce the previous comment I've personally seen a 36 drive 160GB raid array running stock RedHat 7.2
:)
:)
So I think this means the kernel supports 160 drives.
It was built as a large data store for Astronomical Data and provides around 5 terrabytes usable, cost around 15,000UKP. It runs an XFS file system because
1) SGI has used it for a while and its stable and has a track record, unlike ReiserFS or EXT3 (Not that I make judgements on this, but if you are going to commit expensive data to the disks you want to be sure.
2) It serves an environment of large SGI Origin machines and so integrates seemlessly.
For the techies:
- 36 160GB EIDE Maxtor Units in hot swap carriers for the array
- 1 80GB EIDE Maxtor Unit for boot and host drive
- one EIDE CDrom. (No Floppy
- Twin Athlon DDR motherboard heavy on RAM
- Twin Gigabit Ethernet cards into local backbone switch.
- 4 3Ware EIDE hardware raid cards.[www.3ware.com]
Config -
The 3Ware cards provide a SCSI host adabpter to the OS, so they look like a single SCSI drive once they are configured.
The CDrom and Boot/Host drive are on the Mothboard normal EIDE channels.
Each 3ware card has eight drives in a Raid 5 configuration, each drive with a private EIDE channel (no slave drives here)
The 4 3ware cards are then software raided as 4 SCSI devices.
The array itself is split logically into volumes to make it easier to manage.
By all accounts the biggest problem was threading 38 individual EIDE cables through the server case, and finding power supplies big enough to keep the disks and fans spinning.
So this is possible right now, I've seen it from stock parts, it took around a working week to build (hardware and software) and it kicks butt
But aren't you missing the point??
:)
Your argument is sound, and presumably arguable, up to your last step.
Whilst only one copy of your CD, be that the physical CD, a copy on your workstation, or a remote streaming server, is playing you are on safe ground - even if it was techincally infringing they would have a hard time prosecuting as they are all equivalent to just listening to the CD - which was not infringing last time I looked!
As soon as you have 2 copies playing you are in trouble as you have 'duplicated' the CD. This may be you listening on your worksation, whilst your daughter listens to the CD at home, or sharing your MP3's to 3 collegues. This is in no way equivalent to just playing one CD.
If you wanted to do this complying with the spirit of the law if not the letter you would need to have a streaming server that would only play back the tracks on _that_ cd to one person at a time.
This is the same problem MP3.com had when it tried to provide a service where you could upload personal MP3's so you could access them anywhere over the net - thier mistake was to do a good technical implementation whereby server space was preserved by only storing the MP3's once. So when I uploaded "N'Sync Greatest Hits"[1] and was the 453rd person to do so it wouldn't create any extra files, only allow me access to already stored ones. This allowed RIAA et al to succesfully argue that many people were listening to the same CD. If every user had a private area a more spirited defence could have been put up, even if the server storage space went through the roof!
[1] I'm kidding okay - any half decent service would refuse the upload
If I play a CD I purchased at home with some friends over, does that constitute a 'public performance'?
IANAL and this is from a UK perspective:
The test for it to be a public performance is that the general public must have access.
So in a physical form, the general public would have to have access to the area the music was being played.
Hence in a shop it is a public performance as the public have access to the shop, but in your home it is not as the public do not have access, only people you invite in.
This is also why you and your friends can watch a video, but a club can't without paying extra fees.
True story - a friend was running a CyberCafe and wanted to be able to stream music to each workstation, so the customers could just select some music on headphones that they liked, rather than playing something on the HiFi. To do this he tried to get a licence to do it properly - but gave up as the licensing authorities in the UK couldn't classify what sort of license he needed! This was about 4 years ago.
I believe the hulls are actually more traditional GRP composites, its just that usually when a boat reaches around 50 foot long you normally build in steel because whilst GRP and similar is great for small light hulls, it gets progressively more difficult to fabricate as the size goes up.
The UK Navy minesweeper fleet was nick named the Tupperware Fleet - Presumably RubberMaid Fleet elsewhere!
Ferrocement Hulls (to give them thier proper name) were reasonably common for 'home build'. You form the hull using a matrix of steel rods and then usually 'spray' the concrete into this matrix, effectively giving you a cast reinforced concrete hull. Whilst these are strong, they are bulkier than steel hulls and can shatter/crack in impacts where steel would just bend or split. These sort of hulls can be quite large, and the concrete sets into a single very strong monocoque structure.
Whilst ferocement hulls do sound wierd, heavier than water steel hulls still work - what is important is that the hull wieghs less than the volume of the water it displaces (Archemedies Principal)
What is wierd is 'floating concrete' that looks like a fine matrix breeze(UK)/cinder(US) building block, but floats because it is mainly air - freaky when you pick the block up and it weighs so little!!!