Path: chuka.playstation.co.uk!news From: Alex Herbert Newsgroups: scee.yaroze.freetalk.english Subject: Re: Interesting memory card fault Date: Thu, 11 Jun 1998 17:27:11 +0000 Organization: PlayStation Net Yaroze (SCEE) Lines: 48 Message-ID: <3580055F.7B8F3F08@ndirect.co.uk> References: <357C8169.9A5E5C0A@compuserve.com> Reply-To: aherbert@ndirect.co.uk NNTP-Posting-Host: dialin0-44.ndirect.co.uk Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 4.04 [en] (Win95; I) Nick Slaven wrote: > I had something unusual happen on my playstation. One of my memory cards > started to malfunction, unfortunatley it was one with all my Gran > Turismo data on it :(, fortunately I managed to copy it before it went > completely bertie :). > Anyway the malfunction was weird, as the memory card seemed to completely > cock up the controller readings, ie when switching on the playstation > without a disk in it, it would keep flicking from the memory/cd selection > screen to the memory card managment screen and back again as if the X > were being tapped continually. > This has got me thinking that the memory cards and controllers are all > linked by one serial address and data bus, having now pulled apart my > memory card, this appears to be true. Yes, I beleive this is true. When connecting a multi-tap, the memory card has to be removed from it's normal slot (as the slot is obscured by the multi-tap's plug) and inserted into socket 1 on the multi-tap. This works for software (including the Yaroze libs) which doesn't even recognise the multi-tap. i.e. a memory card can be read/written to through a controller's socket! > This got me thinking about my dual shock pad, & how to get it to > wobble, no I havent, but during experimentation with it I have noticed > that the address returned for port 1 always points to physical memory > location 0x8004EAEC, and port 2 always points to 0x8004EB10, this is > slap bang in the middle of the system area. Does anyone know if these > ports are memory mapped, or does the OS just stick the data at those > addresses? > This is probably no big deal, but these addresses are 36 bytes apart > rather than 34 bytes as implied by p104 of the yellow book. So the > final question is what do the extra 2 bytes do & will they make the > multitap work, as they didn't make the shock pad wobble (admitedly > I didn't try writing all 65535 combinations), or are they just padding? > This got me thinking along similar lines also. If we can write to a memory card through the multi-tap (which is only connected via a controler port) then we are half way there. Now if only I could find out what the OS is actually doing to write to a memory card... Does anyone have a copy of the Yaroze libs source code? (only kidding) I think the addresses given above will vary depending on the libs used, and will probably differ from version to version. I think the data from the pads is copied to RAM at this location by the OS.