The Zemina is quite identical to other FM-PAKs, so i think that will work. Not the orriginal FM-PAC due to memory mapped i/o.
If A14 is not used the 27256 indeed is only used half. Maybe a 256 was cheaper than a 128! I did not take my Zemina apart yet :) ----- Original Message ----- From: "Richard Atkinson" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, January 18, 2002 16:46 Subject: Re: Sega Master System MSX-MUSIC adaptor > On Fri, 18 Jan 2002, Hans Otten wrote: > > > I did not check the address line logic in your diagram, it seems allright. > > All necessary lines are covered (slot select and CSx are most important) and > > kept high. Addresslines above A7 are therefore irrelevant, since the inernal > > rom will stay disabled. > > Thanks, Hans. I've made a clearer version of the schematic, which is > functionally identical: > > http://student.cusu.cam.ac.uk/~rga24/computer/projects/adaptor-simplified.pd f > > I tied spare lines high to keep CMOS input buffers happy, although my > Zemina uses even fewer lines than I have connected. Hopefully this will be > compatible with other MSX-MUSICs out there. > > Curiously, my Zemina doesn't use A14 even though it has a 27256 ROM. Could > it be using just half of the chip? > > > If the clock is equivalent to MSX then it is doable this way! > > > > What is I/O address F2 used for anyway? It is now just a r/w store? > > No one seems to know what actual hardware is inside the Japanese Sega > Master System or Mark III FM expander, but the software routines check > that this location can store bits. There are other questions too, which > will be answered when someone finally takes a Japanese SMS apart. > > > Richard > > -- > For info, see http://www.stack.nl/~wynke/MSX/listinfo.html > -- For info, see http://www.stack.nl/~wynke/MSX/listinfo.html
