James Mckay is the author of MASSAGE, the one and only Master System emulator out there as far as Sega Master System World is concerned. James took time out from his gruelling schedule of programming, more programming and generally being clever to answer these questions....

"How do you set about writing an emulator?"

First you need information on the system you are going to emulate, in the case of a computer this is easy, it'll have manuals and you can write programs to see what happens.  For a console you have to find the information, a much trickier task, basically you just have to be lucky to find anything.

Then you have to find out how to do certain things like activate screen modes/open windows etc for the machine that you are writing the emulator on.  Fortunately there is a lot of example source code available for download.

Then you'd have to find a couple of weeks to knock it all together.

In the old days you'd have to write the emulation code for the main processor, but nowadays I suppose you'd just download it from somewhere.

What machines do you own?

I have:

Megadrive (and Power Base converter), Mega CD, Saturn, SNES,
Neo Geo, Atari Lynx, Atari 2600, Spectrum (*4), C64 (*2),
Amstrad CPC 6128 and a 486SX-25 PC.

What's your favorite Master system game? Do you even play them?

My favourite has to be Wonderboy In Monsterland, I suppose, although I don't
really play the games very much except to test them out whenever I make a
change to the emulator.  Playing them on the emulator I can only get 100%
speed in frame 1/5 anyway.

How did you decide the pricing of Massage, seeing as just about every
other emulator out there costs $35?

I decided that I didn't want to get hit by the excuse that people always give
 for regged emulators, that they are overpriced, and I thought that a lower
price would lead to greater sales which isn't really true.  If I made the
price any lower then some people would be paying more for postage than they
would for the emulator!

What is the most difficult part of a machine to emulate?

The processor, it has so many niggly little flags to get right and there are
so many combinations of instructions, registers and flags that it is
impossible to determine that it is working 100%, you just have to keep trying
it with different titles over and over again.

What sort of excuses do you get from people who don't want to register?

1.  "It's incomplete."

Exactly what do they expect?  Information is hard to find, and when you get
it, it rarely contains details about those little hidden quirks that games
use on rare occasions.  It's funny how even though it is incomplete, so
filthy and degenerate that it's not even worth the time of day, it is still
on their hard drive or web page!

2.  "Do you only have the ROMs that you have the original cartridge for?"

I see, so I'm not allowed to download Golvellius to try and get it working.
I'm sure everyone would love that, don't you know that you'd be stuck with
R-Type, Outrun, Sonic 1, Sonic 2 and a few others if I hadn't had the ability
to see cartridges that I did not own.  Do you think that there are shops all
over the place which I can just walk into and buy games that have been out of
circulation for years?

Or do I delete them after I have got them working, then when I make further
changes to the emulator I then have no idea if it has a detrimental effect on
all other games?

3.  "Go back to the voluntary donation system, and those who have the money
will pay."

Ridiculous!  Over the period of time (sms 0.0a to Massage V0.61) a total of
THREE people out of the entire online population thought it was worth 5 quid!

4.  "Sparcade runs all the games I want to play."

Har har har!  That's a good one!  Apart from the inaccurancy of the
statement, why do they bother telling me this?  Why not just use the other
emulators?

What are your future plans, emulator-wise?

Well, I won't be releasing another shareware emulator ever again, it's more
trouble than it's worth, I bet that more people downloaded the pirated
version of Massage (from those unnamed web pages) in one day than have
registered it over the entire history of Massage.

As for releasing freeware emulators, I will certainly be continuing to
support x128.

Do you have any tips for people wanting to write an emulator?

1.  Only release an emulator with some software/hardware to copy the games
onto the PC as part of the package.

Otherwise you get pestered for ROMS, etc...  In fact, you'll probably still
get pestered for ROMs anyway.

2.  Just wait, and somebody else will probably write the emulator instead!

This is a great idea!

3.  Think carefully about it, fame without the fringe benefits is infamy!

You'll never get rich from an emulator.

What about the future of the emulator scene?

I think it is doomed regardless of whether emulator authors get fed up or
not, quite simply we are running out of things to emulate!

I can't think of any 8-bit machine that has not been emulated, and there
weren't that many 16-bit machines and the 32/64-bits are some way away from
being emulatable.

There is arcade emulation, plenty of little games there, very much an
untapped resource with plenty of titles to do, unfortunately arcade games are
a fairly hollow experience, you play them once, twice, and that's it - nearly
all the arcade games being emulated are the very old single screen type of
game, the situation is improving, but I don't think it'll get significantly
better.

Well, there you have it. James McKay, writer of Massage. You can get the shareware and freeware versions of massage from the Download Page or The official page. If it works, register it and maybe we can persuade James to write that N64 emulator for us ;-).