Path: utzoo!news-server.csri.toronto.edu!rutgers!cbmvax!bagate!dsinc!unix.cis.pitt.edu!zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!yoyo.aarnet.edu.au!sirius.ucs.adelaide.edu.au!adam.adelaide.edu.au!phil From: phil@adam.adelaide.edu.au (Phil Kernick) Newsgroups: comp.sys.amiga.misc Subject: Re: Mac emulation Message-ID: Date: 15 Mar 91 04:07:35 GMT References: <7990@crash.cts.com> Sender: news@ucs.adelaide.edu.au Followup-To: comp.sys.amiga.emulations Organization: University of Adelaide, South Australia Lines: 36 Nntp-Posting-Host: adam.adelaide.edu.au hawk@pnet01.cts.com (John Anderson) writes: >>WRONG. Dumping the Mac ROM image to an EPROM, then using the EPROM in the >>A-Max cart will NOT work. The actual Mac ROMs are 'special' in some way, >>how that is, I don't know exactly. What I understand it to be is that you >>need to strobe a location several times before they will dump their image >>to you. The A-Max software does in fact do this and if you are using an >>EPROM copy, it will not work. As I have pointed out, the above assertion is incorrect. There is nothing special about the Mac ROMs. >Is this why it takes so long to copy the Mac OS from the cartridge to the >computer? Or is it because the disk drive port is slow? As I also said earlier, it is slow because the AMax cartridge strobes that ROM image out 1 bit at a time. Small calculation gives: 128 x 1024 x 8 = 1048576 bits or 1 Megabit If this were strobed in at 28.6kHz (system clock speed) it would take: 1048576 / 28600 = 36 seconds Which is about what it takes. There is really no mystery about it. Phil. ** Followups directed to comp.sys.amiga.emulations ** -- o| /// Phil Kernick EMail: phil@adam.adelaide.edu.au |o | /// Departmental Engineer Phone: +618 228 5914 | o| \\\/// Dept. of Psychology Fax: +618 224 0464 |o | \/// University of Adelaide Mail: GPO Box 498 Adelaide SA 5001 |