Path: utzoo!attcan!utgpu!watmath!iuvax!purdue!haven!grebyn!ckp From: ckp@grebyn.com (Checkpoint Technologies) Newsgroups: comp.sys.amiga Subject: Re: Are there any programs that allow reading Apple ][ disks? Summary: GCR table already in the Amiga? Where? Keywords: disk encoding, MFM, GCR, 13-sector, 16-sector, ProDOS, 5.25, 3.5 Message-ID: <12938@grebyn.com> Date: 16 Aug 89 14:57:07 GMT References: <495@tardis.Tymnet.COM> <15704@pollux.UUCP> Reply-To: ckp@grebyn.UUCP (Checkpoint Technologies) Organization: Grebyn Timesharing, Vienna, VA, USA Lines: 18 In article <15704@pollux.UUCP> bjc@pollux.UUCP () writes: > >The Amiga has a GCR lookup table built in. In fact, you can use GCR if >you prefer, but it only works half as fast as the MFM encoding. >The RKM states that the GCR capability in the Amiga is the Apple version. > As far as I know, the Amiga does not have a GCR translation table built in. It does have the ability to read CGR disks (witness: Disk-2-Disk and Mac-2-Dos and AMAX), but this is because the Amiga's disk controller gives the CPU data below the formatter level, so the CPU can perform whatever encoding it desired. GCR is generally slower than the Amiga's MFM scheme, because the blitter can be used to encode MFM, while the CPU must do the GCR encoding/decoding. -- First comes the logo: C H E C K P O I N T T E C H N O L O G I E S / / \\ / / Then, the disclaimer: All expressed opinions are, indeed, opinions. \ / o Now for the witty part: I'm pink, therefore, I'm spam! \/