Alpha v0.1 Content creator, software developer F.A.Q. and mini prep guide targeting Sega’s 32X Mars CD. Hopefully this solves the biggest problem once and for all for most developers and programmers. Unfortunately the internet is flooded with pirating and false information so many developers and programmers are attacked by concerns. We as developers have the right to program how we want, especially if it doesn’t break legal rules or cause infringement. Sometimes it’s not fair for us developers since we have to work our way through piles of pirating sources just to get something interesting and useful. Do we have to pirate and face hostile culture just to program? This F.A.Q. encourages programmers and developers who are stuck with the W.W.W. internet as source of information. This F.A.Q. is provided as-is though it would be nice to receive donations. Please give thanks as much as possible. Any similarity to other F.A.Q.s is purely coincidental and unintended, while those sources that are used will be referenced as accurately as possible (sorry to those I’ve forgotten to give special thanks to if any). Lots of information was gathered from various sources which may or may not be reliable. Reading this F.A.Q. is solely your responsibility and you accept any possible harm caused from reading this F.A.Q. including damage to your property. Sorry for the inconvenience. Lots of difficulties are involved finding reliable information with the current state of the internet (W.W.W.), as of 09-11-2019. One of the biggest problems is the W.W.W. being a sort of black marketing tool for purchasing goods as well as pirating. Searching google.com for information usually results in marketing ads and retailers now, and most websites which did have reliable information have been placed on the “Wayback Machine” www.archive.org or simply lost; archive.org will sometimes have illegal copyright content which is rather odd and doesn’t look good for information which is legal. It’s unknown why this is happening and it’s annoying considering some genuine information isn’t really a big deal in the first place, but if you find good information you should definitely copy the webpage to a local storage cache and update any differences for safekeeping. Ads which show up as a result for searching information isn’t really the problem, but the problem is lack of websites with useful information and those that do mysteriously disappearing. There was definitely more interesting information available on W.W.W. pre-y2K. Other problems are technical terms used for describing technology involved and getting accurate genuine answers with proper pronunciation for the technology in question. Sega 32X Mars has had lots of misinterpretation as a result of the market and websites assembled as a result of the market; this includes everything else related, in-between and similar (Nintendo, Microsoft, Macintosh, etc.). When you hear information about something, don’t trust the market! Simple as that! This F.A.Q. aims to solve those issues and some jargon may sound a bit odd as a result; some information may seem unreliable as well but this is a result of most sources being part of the market or somehow influenced by it. Sega’s 32X Mars was a hardware application (and possibly still is) from Sega Sammy. Nextstep assembled a marketing campaign called “Welcome to the Next Level” using 32X Mars in partnership with Sega starting in 1994. Nextstep appears to have been bought by Microsoft in 1996 which is about the same time 32X Mars reciprocated from the market. It’s quite possible 32X Mars was in fact supposed to be a Nextstep computer with a optional catalog of video games. There’s a lot of coincidence with Motorola based computers being implemented about the same time from Macintosh, Amiga and Nextstep, including network technologies like the W.W.W. internet, A.O.L. (America Online), Xband, and other networks like Midway’s Wave network. Nvidia NV1 was and Microsoft’s Sidewinder gamepad are amongst others. Many other corporate groups and large vendors (Nintendo and Microsoft mostly) around the same time also made lots of confusion with canceled markets (e.g. Nintendo Virtual Boy, Project Reality Ultra64, Windows 3.1, Windows Chicago, Macintosh System7 for PowerPC, Sega Nomad, Sega CDX, etc.). 32X Mars with the CD hardware and a complete local buffer was quite possibly the original Sega Saturn and implemented as far back as the early 1980‘s (yes the early 1980s!). Clues to this stem from signs on the “Sega Genesis” catalog console boxes using the term “core”. Some of these boxes were used in Model 1 based Sega Genesis variants without “High Definition Graphics” logo (plain black). Term “core” was also used for Majesco Sega Genesis Model 3 console catalog boxes. When analyzing Mars 32X CD, you’ll notice Sega Genesis really is the “core” of the machine! Mars 32X was possibly a result of a modularized machine in order to satisfy the market. It’s unknown why the term “core” is used on these catalog boxes of Sega Genesis, but it’s definitely the core of the CD and 32X Mars hardware. To make things more confusing, there was a Neptune console implemented but never marketed; this machine basically included Mars and the “core” without CD hardware or local buffer and is designed to be compatible with the marketed modularized CD hardware cataloged as “Sega CD” in United States (“Mega CD” in other countries). “Sega CD” seems to have also been used by the Nextstep marketing campaign possibly before Mars 32X. Why mention all this? It’s important to realize how to properly define a target when development and programming take place. As mentioned previously, the market confuses things greatly! Basically we’re dealing with what is possibly the original Sega Saturn but it’s still a undefined variable, and even if it wasn’t we’d have two different targets with the exact same name “Sega Saturn” which wouldn’t make sense (Sega Saturn with core 6-bit VDP + 15-bit superVDP, and Sega Saturn with background VDP+Quad VDP). The most suitable target name appears to be “Mars CD”, “Core Saturn” (since it uses ”Sega Genesis” M68000 for the core)or “Saturn16“. Did I mention no buffer? Yes! This is the biggest problem with Mars. There are some stolen Hardware-SDK manuals for the core “Sega CD” (or “Mega CD”) using a person’s name, “Rex Sabio", which do in fact mention a “Extension Ram Cartridge”. Whether these SDK manuals are genuine or not, it does exploit an obvious issue with Mars; no buffer. Did I mention the market makes things confusing? Well it gets even better! “Sega CD” did have a hardware peripheral called “Backup Ram Cartridge” marketed but is only designed for save game function for marketed catalog titles for “Sega CD”. Sega also implemented the 315-5755 I.C. 6-bit memory pager but unfortunately is unavailable outside of only a couple obsolete cartridge ROM catalogs; this I.C. was actually termed mapper by Sega probably for human friendliness and relationship with content creators and graphic designers. Core “Sega CD” does have some form of buffer but it’s barely enough for core “Sega CD” content without Mars; it’s only 512KB+256KB. If you analyze 3DO, Playstation and Sega Saturn, by comparison these CD consoles similarly have a minimum amount of buffer for acceptable quality content with 3 megabytes at least (Saturn has 4 megabytes local buffer); 3DO is also older than Mars. 768KB is definitely not enough buffer for Mars and even if adding other ram regions it’s still only 1.25 megabytes! Sega Saturn was probably the only console with a small market for anything similar to this “Extension Ram Cartridge” which was only marketed in Japan as Ram cartridge (1, maybe 3 and 4 megabytes variants) for select Capcom CD catalogs and very few others (mostly fighting genre video game catalogs). So how do we solve this buffer problem? This F.A.Q. aims to provide a solution to the empty buffer of Sega Mars. Another confusion about Mars is the fact it’s still the same 16-bit core (like the Sega Genesis). This makes the memory space very narrow at only 4 megabytes. Surely the Sega Saturn has much more, or a standard Pentium or 486 IBM P.C. having about 2048 megabytes of memory space. To solve this issue, a pager must be implemented in a cartridge. Same kind of situation exists with the 1985 Nintendo Entertainment System (Famicom in Japan) where most Catalog cartridge titles implemented a pager (actually called mapper according to these corporate groups. Sega wasn’t the only source with term mapper after all!); this was mandatory due to the very small memory space available when buffering content on-the-fly from cartridge, and the largest paged space used seems to be one megabyte for a Nintendo Kirby cartridge ROM catalog. As mentioned before the 315-5755 I.C. from Sega is unavailable. 74ls612 is a very standard 7-bit (pseudo 8-bit) pager which should allow at least 16 megabytes of paged ram. It can be used with a 72pin simm socket, 70ns (or faster) 72pin simm EDO or FPM RAM and a blank cartridge PCB for the core (“Sega Genesis” in United States and “Mega Drive” elsewhere) with proper assembly. 16 regions and 256 pages are available hence pseudo 8-bit pager; unless the pager allows 8 regions at twice the size it’s only possible to page 16 megabytes of RAM (or ROM if you must impose a cartridge ROM program) without issue. 256KB are available in each region which allows more precision but there may be some concern regarding page-memory table complexity on the core. Considering the 315-5755 I.C. from Sega, this 74ls612 pager might cause slowdown; if speed is more than acceptable with all pages and regions under certain situations, 64 megabytes could be paged and used. Unfortunately no testing has been done. Parts are readily available on EBAY, digikey and mouser on the W.W.W. and amount to about $27.00 after shipping and taxes domestically in United States as of this writing 09-11-2019. Core CD provides two system modes with two functions in each mode, according to the stolen Rex Sabio Hardware SDK manual. Second function in each mode is the one to use; it’s provided to initialize cartridge space with the cd hardware so both regions can be shared. System mode provides the program startup location (either CD or cartridge) and changes location to the cartridge space accordingly. As mentioned the core CD can be shared with page mapped “Extension Ram Cartridge” either way program startup reciprocates. Other useful features may be added like a D.I.P. switch, parallel port, and optional small ROM for compatibility with existing cross-over systems (such as those from Cross Products). A second pager could be utilized to add a small portion of static RAM for Save game function. Quite a few ideas are possible with these pagers. It’s worth noting each gamepad-joystick plug on the core doubles as a LPT parallel port with less pins so there’s yet more ways to interface Mars (or should I say Saturn16?) with different computers. Better ways exist for implementing a full MarsCD application with local buffer instead of the incomplete marketed result. A good way is removing the cd drive from the cd hardware side and imposing a din plug or rj45 cable on a broken multimedia console (portable dvd player, broken laptop, vcr, etc). You can further assemble the cd door sensor with a custom wooden box or a broken portable cd player. Most internals from the core and mars can then be muxed with the remaining cd hardware without the cd drive and assembled into a broken multimedia console of your choice. As a result, you can plug the cd drive via rj45 ethernet cable and have a better quality and smaller Sega Mars CD. You could further add other features like the 74ls612 paged buffer directly with a selectable cartridge adapter to disable the buffer anytime you insert a cartridge; it’s recommended to assemble the cartridge plug flat and horizontal to keep machine uniform and small. Custom 9v powerbank could also be utilized since MarsCD is very efficient even for 1994. As a finishing touch buy a ntsc/pal compatible 7“ screen from Ebay-china and use hinges from a broken laptop lcd-lid to mount, and leave enough space for a future keyboard. Stay tuned for more information: pinout of 74ls612, and cartridge space location of core CD system mode 2 and 1 .