ralph@laas.fr (Ralph P. Sobek) (05/27/91)
I have tried a number of different formatters, both public and shareware. I would very much like to know *why* most of these formatters add 5 sector FATs? There are so few that propose 3 sector FATs! As I understand it, GEMDOS accepts FATs with both 12-bit and 16-bit entries. In all the floppies that I've seen, I have only seen FATs with 12-bit entries. Here are my calculations: # FAT | 12-bit || 16-bit sectors |clusters|sectors| bytes ||cluster|sectors| bytes 1 341 682 349,184 256 512 262,144 2 682 1364 698,368 512 1024 524,288 3 1023 2046 1,047,552 768 1536 786,432 4 1364 2728 1,396,736 1024 2048 1,048,576 5 1705 3410 1,745,920 1280 2560 1,310,720 6 2046 4096 2,095,104 1536 3072 1,572,864 So, other than for 1.4 Mb floppy drives, wouldn't 3 sector FATs suffice for floppies even with 84 tracks? For single-sided floppies, I suppose that one could use 1 or 2 sector FATs. Is the real reason hidden somewhere in the Developer documentation? If STs would generate 3 sector FATs, then we would not have all those FAT viruses. Just curious, -- Ralph P. Sobek Disclaimer: The above ruminations are my own. ralph@laas.fr Addresses are ordered by importance. ralph@laas.uucp, or ...!uunet!laas!ralph If all else fails, try: sobek@eclair.Berkeley.EDU =============================================================================== Proud owner of a Mega 4 ST. Wishing it was a Mega STe! :-|
csbrod@immd4.informatik.uni-erlangen.de (Claus Brod) (05/28/91)
ralph@laas.fr (Ralph P. Sobek) writes: >I have tried a number of different formatters, both public and >shareware. I would very much like to know *why* most of these >formatters add 5 sector FATs? There are so few that propose 3 sector >FATs! You are right, 3 FAT sectors are sufficient. All the formatters I've written generate small FATs and give you additional space on every disk. To my knowledge, there's no special reason why the Desktop uses a 5-sector-FAT. ---------------------------------------------------------------------- Claus Brod, Am Felsenkeller 2, Things. Take. Time. D-8772 Marktheidenfeld, Germany (Piet Hein) csbrod@medusa.informatik.uni-erlangen.de Claus_Brod@wue.maus.de ----------------------------------------------------------------------
Roger.Sheppard@actrix.gen.nz (Roger Sheppard) (05/28/91)
In article <RALPH.91May27161746@orion.laas.fr> ralph@laas.fr (Ralph P. Sobek) writes: > I have tried a number of different formatters, both public and > shareware. I would very much like to know *why* most of these > formatters add 5 sector FATs? There are so few that propose 3 sector > FATs! > > As I understand it, GEMDOS accepts FATs with both 12-bit and 16-bit > entries. In all the floppies that I've seen, I have only seen FATs > with 12-bit entries. Here are my calculations: > > Is the real reason hidden somewhere in the Developer documentation? > If STs would generate 3 sector FATs, then we would not have all those > FAT viruses. > -- > Ralph P. Sobek Disclaimer: The above ruminations are my own. > ralph@laas.fr Addresses are ordered by importance. > ralph@laas.uucp, or ...!uunet!laas!ralph > If all else fails, try: sobek@eclair.Berkeley.EDU > =============================================================================== I did read some where that the Atari 5 sector FAT, was a Bug, should be 3 sectors, and this was going to be fixed in TOS 1.4. But because of compatibility problems it had to be left in. -- Roger W. Sheppard 85 Donovan Rd, Kapiti New Zealand...
johnj@knor.prl.philips.nl (John Janssen) (05/29/91)
Note that these two sectors are 'very' nice to hide software. And as there are two FATS, this gives you 4 sectors. Nice for a virus-) -- John Janssen Check the email address in the header, as this J.v.Deventerstr.1 may have been filled in wrong by the system. Venlo Holland +31 77 513177 Reply to: johnj@idms.prl.philips.nl