I was just looking through random stuff about the PSP and I came across a blurb about the design. UMD uses red laser and can store as much as 900mb single layer. CD used infrared laser and a 3" CD holds about 100mb. 3" is a lot bigger than UMD. So I was wondering is there really that much of a difference in data density? Red wavelength isn't far from IR yet UMD seems to pack many times more data than CDs.
You could say the same thing about DVD and CD - the answer's "yes, there is a big difference in data density", as you'd expect from two technologies separated by two decades. UMD was based on DVD technology anyway, IIRC.
So hypothetically a hacked DVD-ROM for smaller spindle size and laser positioning closer to the center hub can read UMD? I forgot DVD used visible red wavelength.
UMD was a wasted opportunity. I loved the format just for the disc caddies, some underlaying coolness to them.
For me, the coolest thing about UMD's is that you could get movies and TV shows on them. Watching Spider-Man or Family Guy on the PSP was so cool.
I don't know that it would be that easy to do. UMD may be based on DVD but an actual DVD-ROM drive may not be capable of reading a UMD because they may have customized more than it could cope with. Encryption would be a possibility. GameCube discs are based on DVD but are encrypted or scrambled.
If I am correct, a gamecube disc uses a Burst Cutting Area to store an encryption table related to the copy protection.
Taken as a whole, the format is pretty DVD incompatible - the low level bits are similar (they both use EFM+ encoding, although the UMD variant has more sync words), but the sector format is completely different - it has no sync in the sector data (because that's done at the EFM+ decoder level) and no mode bits (because all UMD sectors are in the same mode) - it's also recorded without sector-level ECC so the sector length on disc is only 2064 bytes, of which 2048 are sector contents (I.E. only 16 bytes of overhead per 2K sector). I haven't checked, but I assume the low-level error correction is different, too, because the row size (and hence the width of a C2 block) has changed - it's 182 bytes on DVD and 172 bytes on UMD.
Same. It did have promise but like Sony's Microdisc Sony didn't allow much information out so it was doomed as yet another propriety format to die alone. No UMD burner, no DIY movies or downloadable games. Guess Sony didn't want people to easily play pirated games or pirated movies? But allowing UMD burner and cheap blanks might have helped UMD format live a little longer. Mechanical drive of any type is still power guzzler. Nintendo 3DS wth similar sized battery can easily outlast PSP on almost anything, even with 2 LCD and 3D mode. Cheap portable DVD player with bigger screen that used existing standard format, no need to buy 2nd's set just for on the go movies. Nowday one can get a new portable player with 7" for under $50, and I regularly see them used in Goodwill for under $10. Usually they all worked, just needed new batteries or new power adapters. And cheap memory didn't help. Today corporate can get 2GB flash memory for probably about the same base cost as one UMD disc with caddy. PSP Go and Vita was wise to drop disc format and go memory only storage. (although Vita memory is shit expensive for greedy reason) Sony could have done something like BUMD, a blu-ray version of UMD with several GB and still be backward compatible with original UMD
