Showing posts with label Sega Master System. Show all posts
Showing posts with label Sega Master System. Show all posts

Tuesday, October 16, 2018

The Analogue Mega Sg – A Preview of the Next Chapter in the FPGA "Console Wars"

Analogue Mega Sg JPN Version
Today, Analogue has made an announcement of its next FPGA retro console. This was a reveal which had been long expected. When the console was revealed as an implementation of the Sega Genesis/Mega Drive, it came as no great surprise to observers like myself familiar with Analogue’s history. Let’s explore some of that history, the specifications of the unit, what you will get for the $189.99 retail price and how this console may fare in today’s increasingly-crowded retro-console market.

Monday, July 18, 2016

Video Potpourri

I am going to discuss a pair of video topics in this post which do not by themselves merit full blog entries on their own.  Each discussion will have a link to a Youtube video demonstrating the topic discussed.

I.  Hercules Graphics Tidbits

Someone remarked on the VOGONS forum that certain 16-color LucasArts SCUMM games, Indiana Jones and the Last Crusade: The Adventure Game and LOOM, do not support Hercules Graphics.  Earlier SCUMM games, Maniac Mansion and Zak McKracken and the Alien Mindbenders support Hercules Graphics in both their original and Enhanced releases.  The Secret of Monkey Island, which came immediately after LOOM, also supports Hercules Graphics in its original 16-color release.


Sunday, December 27, 2015

33 Sega Master System Games Worth Playing

The Sega Master System was not very successful in the United States or Japan, where Sega was unable to overcome Nintendo's massive successes.  It was markedly more successful in Europe and especially Brazil.

Unfortunately, only 116 games were released in the United States.  Quite a few of those games are pretty decent, but there is a lot of crap and uninspired games for the system.  There are also quite a few decent games that only came out in Europe.  However, for the US only releases, I can still cull 30 games worth playing from the library.  Usually I list every game in a series because the gameplay is usually consistent and you can know what to expect, but I will exclude a dud game.

I am not including any SMS games that were ports of Genesis games or which have a Genesis version unless the SMS game offers something special.  The Genesis is an extremely common system and the first two models have backwards compatiblity with SMS games with an adapter.

Title Notes
Action Fighter
Alex Kidd in Miracle World
Alex Kidd in Shinobi World
Alex Kidd: High-Tech World
Alex Kidd: The Lost Stars FM Synthesis Support
Alien Syndrome FM Synthesis Support
Bubble Bobble
California Games FM Synthesis Support
Castle of Illusion starring Mickey Mouse Not a Port of the Genesis Game
Choplifter!
Fantasy Zone
Fantasy Zone II FM Synthesis Support
Gangster Town Light Phaser Required
Golden Axe Warrior
Golvellius: Valley of Doom FM Synthesis Support
Master of Darkness
Maze Hunter 3-D
Missile Defense 3-D

FM Synthesis Support, 3-D Glasses Required
Light Phaser & 3-D Glasses Required
Penguin Land Battery Backup; FM Synthesis Support
Phantasy Star Battery Backup; FM Synthesis Support*
Power Strike II
Psycho Fox
R-Type  FM Synthesis Support
Rampart
Shinobi FM Synthesis Support
Sonic The Hedgehog
Sonic The Hedgehog 2
Not a Port of the Genesis Game
Not a Port of the Genesis Game
Space Harrier 3D 3-D Glasses Required; FM Synthesis Support
Wonder Boy
Wonder Boy III: The Dragon's Trap FM Synthesis Support*
Wonder Boy in Monster Land FM Synthesis Support
Zillion
Zillion 2: Tri Formation FM Synthesis Support

I tried to include Light Phaser and 3-D Glasses games since these were significant (Light Phaser) or unique (3-D Glasses) peripherals.  I also have noted which games have battery backup save RAM, which is a rarity for 8-bit Sega cartridges.  Finally, I have also noted which games have an optional FM Synthesis soundtrack.  For the games with an asterisk, you will need a hack to play them in anything other than a Japanese system.

If you buy a SMS, you will have a built-in game.  Early consoles will have a simple snail maze game, later consoles may come with Hang On and Safari Hunt, just Hang On or Missile Defense 3-D.  Master System IIs should come with Alex Kidd in Miracle World.

There are a couple of games that almost made the list.  Ys: The Vanished Omen has FM Synthesis but the game is too slow and difficult compared to the Turbo CD version.  King's Quest is interesting but not nearly as good as its PC original.  Miracle Warriors: Seal of the Dark Lord is the only other RPG released for the system, but it has nothing to really distinguish itself from a typical JRPG before they became good.

Europe got more games than the US did, and some of them are pretty good and will run in a 60Hz NTSC System.  Ultima IV: Quest of the Avatar is a superb port of the PC game, much more faithful to the PC source than the NES version and has FM Synthesis music.   Ninja Gaiden is a passable game if you need an 8-bit Ninja Gaiden fix, but it is not near the NES games.  Despite what SMS Power! may contend, Sonic 2 runs without any real issue in an NTSC machine.  

Sunday, April 26, 2015

More Computer Adventure Game Console Ports - NES and SMS

Home consoles of the third generation, such as the NES ans SMS, were sufficiently popular that computer game makers wanted to get a piece of that action.  While a very successful computer game may sell 100,000 copies across several incompatible computer platforms, a successful cartridge-based game could easily sell five times that number.  That would more than make up for the increase in cost of manufacturing cartridges versus writing to floppy disks.

The adventure game genre was extremely important in the 1980s, one of the prestige computer game genres along with role playing games, flight simulators and turn based wargames.  Most of the adventure games of the 1980s were text-based and used keyboards for input.  This is not well-suited to consoles of the third generation, which generally lacked keyboards.  Some games were beginning to use mice, a peripheral that would only come to consoles in the fourth generation.  Third generation consoles used D-pads and joysticks for the most part.  

Maniac Mansion

 The gold standard for adventure game ports for the third generation undoubtedly was the NES version of Maniac Mansion.  LucasArts developed Maniac Mansion for NES in close conjunction with Realtime Associates and it was published by Jaleco.  Despite the heavy censoring hand of Nintendo of America, the published cartridge does justice to the original Commodore 64 game and works very well as a NES game.  Play the prototype version and you can bypass almost all the censorship.  LucasArts did a great job stuffing the entire game into a 256KB cartridge.  This was by far the best showing LucasArts made for the NES.  Its other games' simply failed to meet the high standard of this port. 

The C64 used a joystick to move the cursor, it was the PC port that added mouse support.  Compared to the original, the NES input was not a real step down.  The low resolution PC port has a rather coarse mouse granularity which makes it a bit less than a perfect input device.  Graphically the game falls in between the low (160x200) and high (320x200) resolution computer versions.  The characters are very recognizable, the backgrounds are generally distinct and the objects can be made out, if a bit small.  Sound wise, the original had little music but what it did have was well done on the NES's 2A03 APU.  LucasArts made the good move of giving each character a portable CD player they could use to turn on or off the character's individual theme songs. They did a great job with these pieces.  It also wisely cut down on the number of verbs to eliminate Fix, What is and Unlock.  


Most importantly, Maniac Mansion had a battery backed save system, even if it only supported one save game at a time.  The C64 and Apple II versions of Maniac Mansion also supported one save, but that was per disk.  

Maniac Mansion was also ported to the Famicom by Jaleco before LucasArts released its version.  The Japanese version looks completely different from the US/European version.  Unfortunately, the Japanese version uses a ludicrously long 83-character password system with the 46 core Japanese hiragana characters and English letters A-T.  The screen does not scroll in this version, just like the Apple II version.  More space is taken up by the various menus, leaving the backgrounds and sprites smaller and less detailed than the US/European version.  The main theme was retained, but there is new background music in the game.  In isolation, it is not a bad port, but it pales in comparison to the LucasArts-led effort.

Shadowgate, Deja Vu, and Uninvited


Also of note, the NES ports of the ICOM Simulations MacVenture games, Shadowgate, Deja Vu, and Uninvited also had battery backed saves.  These games were originally published for the B&W Apple Macintosh computers.  The Macintosh popularized the graphical user interface and multiple "windows", and native-Macintosh games generally used the high resolution to use implement the game using multiple windows.  The ICOM games, using the MacVenture engine, are no exception.  When ported to other computers, these windows were generally retained.  The windows had the benefit of being repositioned anywhere on the screen.  Some of the windows, like the inventory window, could be resized.  

The NES versions of these games were ported by the Japanese company Kemco/Seika.  K/S was never a top-tier NES developer and these games may be the best representatives of its cartridge output on the NES. These games used a small main graphics window and little animation, making those graphics easy to redraw for the NES.    They consolidated the command window and the description window so that the descriptions would appear when you do something, otherwise you would see the commands, exits and the functions to save.  

Instead of using an icon-based inventory, K/S used a text-based inventory.  The windows in the NES games cannot be resized, making an alternative necessary.  Otherwise, inventory objects would quickly overlap each other.  However, K/S could have used a simple scrollable inventory window like the DOS and C64 versions.  By using text, K/S did not have to draw the graphics for those items.  While it makes inventory management a bit simpler, it can be time consuming to go through multiple pages of item listings.  

While the PC versions are generally silent, the NES versions have music throughout.  The music in these ports is generally appropriate but somewhat simplistic.   There was also some censoring going on, as the descriptions of when you die are sometimes less graphic in the NES versions compared to the Mac originals

King's Quest V

King's Quest V was released in 1990 for MS-DOS.  It came in a 256 color version or a converted 16 color version and used 320x200 resolution graphics.  It also supported Adlib FM Synthesis and Roland MT-32 LA Synthesis.  The 256 color floppy version takes 8.64MB of hard drive space and the 16 color version 5.05MB.  It also is intended to work with a mouse on a PC with 640KB of RAM and a 16-bit 80286 running at 10MHz or better.

Sierra thought it was a good idea to port this popular PC game to the NES.  The port was done by the Hungarian company Novotrade, more famous for its Ecco the Dolphin series.  The game was distributed by Konami.  The NES KQ5 cartridge had only 512KB of ROM and an extra 8KB of RAM.  It is no joke to say that porting this game to the NES would prove very challenging.  The NES had an 8-bit 6502-based CPU running at 1.79MHz, 2KB of RAM and 5 PSG-style audio channels.  Graphically, the NES PPU could support a 256x240 resolution (no more than 224 lines were generally used) with no more than 25 colors on display from an effective palette of 54 colors.  The NES uses a 8x8 tile-based graphical display with sprites.  There were substantial limitations on the colors used for the background tiles and sprites.

The PC graphics adapters generally had no limitations on what colors could be used at what locations on the screen.  As bitmapped displays, they did not need to breakup images into tiles.  When Sierra was making KQ5, it turned to artists to make real art with paint and canvas which Sierra scanned and converted to 320x200x256 color images.  Its previous games had relied to no small extent on computer-drawn line art.  Sierra's use of hand-drawn images is one reason why the PC version of KQ5 still looks good today.  At the time it was a revelation.  

The NES shows KQ5's graphics in a 224x208 resolution, leaving borders on all four sides of the screen. Even though these are visible on a TV screen, it is generally not a distraction.  However, what is distracting is the background graphics.  Since the NES uses tile-based graphics, tiles are frequently reused to save space in the ROM.  In KQ5's case, this reuse is often noticeable because the tiles just do not seem to match up as you would expect them to match up.  The result is rather ugly looking and can make images hard to make out without staring at them.  Also, there is a substantial lack of color in the backgrounds with simple red, blue, green, yellow and brown predominating.  Some of the talking head portraits, like King Graham's, are very ugly.  All-in-all, this makes for an ugly game compared to the 256 color or even the 16 color PC versions.  

Much of the music from the PC version is included, and while the music is recognizable, the style is not well-suited to the NES APU.  A lot of ambient background animation and sound effects are lost, giving the world of Serenia a rather empty, lifeless feel.  

The saving system uses a combination of temporary saves and passwords.  The temporary saving feature works similar to the saving on home computers.  You enter a name for your save game and can reload it if you die.  You can also load a game from the menu.  It can hold up to twenty file saves at a time.

Permanent saving is done with a 15 character password, consisting of letters, numbers, space and -.  As far as NES passwords go, there are far, far worse password systems.  However, the need for passwords would have been averted if Sierra or Konami had ponied up the extra quarter per cartridge for a save battery.  The hardware is all there in the cartridge to store the saves permanently except for the battery.  

This port did tone down some of the difficulty and unfairness of the PC original.  You cannot walk into the river that runs by the Pie Shop, Inn or Town.  The maze-like desert area has been made smaller.  It also cut out some of the more unnecessary elements like being able to enter Crispin's house after the game starts.  However, most of the text dialogue is intact and unchanged.  

The worst part about this port is the truly awful way they implemented the icon interface.  In the PC version, everything is controlled by the mouse icons.  If you want to change the icon, you either right click to select the icon or you move the cursor to the top of the screen and select the icon you want.  The NES version did have the bright idea of using the D-pad to control Graham directly due to the less-than-idea method of using the D-Pad to control a cursor, but that is where the inspiration ended.  

The NES version's controls work like this.  Select makes the icon button appear, start pauses the same, B will allow you to use cycle through the Look, Talk and Action icon, and A will allow you to carry out an action from the icon bar.  The icon bar will allow you to replace D-pad movement with cursor movement via the Quick Travel icon.  This is very confusing from a PC player's perspective.  It leads to a constant struggle to figure out how to select an item from your inventory and how to get rid of the icon bar.  

There is only one cursor, an arrow.  Why Novotrade could not have implemented a look, talk, action and item cursor is beyond me.  Had they have done so, the menu system could have been simplified.  Why couldn't select be used to make the icon bar disappear?  I agree that B to cycle through/cancel and A to confirm is appropriate, but the implementation needed more work.  Ultimately, it is the controls that drive the final nail into this port's coffin.

King's Quest - Quest for the Crown

If you think that the King's Quest series could not have been further sullied on consoles, think again.  Prior to Sierra's dalliance with Nintendo, it teamed up with Parker Bros. to release the original King's Quest for the Sega Master System.  This port was done by Microsmiths,  whose only real claim to fame was the golf simulator Mean 18.  
King's Quest - Quest for the Crown for the Sega Master System comes on a 128KB cartridge.  Despite having less than half the space of a floppy disk, Microsmiths was able to cram just about everything from the PC version into the SMS version.  Saving and restoring a game is done via a 31-character password with A-Z and 1-6 being used.  If you encounter one of the many cheap deaths, you have to input this monstrosity.  Sega did have a 128KB cartridge with battery backed save RAM, but Sierra and Parker Bros. did not want to pay the premium.  
There are new dangers in this version.  If you go to close to the hole with the dagger, you will fall in and die.  Falling off the tree with the golden egg is always fatal.  When you enter the woodcutter's house, you appear on the screen just above a deadly hole.  Some puzzles are handled differently.  You should push the rock in the usual PC way.  You can deal with the witch even if she is at home when you enter her house.  The stairs up the mountain and in the leprechaun's cave are far more deadly than the beanstalk.  Oftentimes you will start on a screen near a fatal area.  Monster pathfinding, however, is comically poor thanks in part to all the obstacles on the screen.  115 points seems to be the maximum for this version vs. 158 points for the computer versions.
Because there is no keyboard, which this game originally used, you have a menu which is opened by pressing Button 1.  This menu will show a selection of verbs in one column and nouns in another column..  Pairing the two and pressing Button 1 again will lead to an action.  The menu will only give potentially valid options based on the room and the items in your inventory.  This eliminates much of the "guess what the designer wanted you to type" aspect of adventure games with text parsers.  Whether this is a good or a bad thing depends on how wedded you are to text parsers, but King's Quest's parser was always rather terse.  The 2 button brings up another menu that lets you duck, swim, climb, look about and jump as well as allowing you to view your inventory, pause the game, see your password and set the movement speed to fast or slow.  
Graphically, things are pretty nondescript.  The backgrounds use the same tiles over and over, so there are screens that look nearly identical.  This can make figuring out where you are confusing.  There is also sometimes an issue about your character overlapping solid boundaries.  It can also be tough to discern exactly where your character is walking.  The graphics are not bad, but they lack the charm of the blocky sprites and line-drawn backgrounds of the PC version.  Sound-wise there is little more sound than in the PC hard disk-installable version.

Larry and the Long Look For A Luscious Lover

I do not discuss homebrew releases often on this blog, but it is not because I am always indifferent to them. In 2014, a homebrew developer called Khan Games (Khan is not a direct reference the Mongol title but short for the programmer, Kevin Hanley, so its pronounced K-Han with a long "a") released a port of the original Sierra AGI version of Leisure Suit Larry in the Land of the Longue Lizards for the NES.  They renamed the game to Larry and the Long Look for a Luscious Lover probably because the name Leisure Suit Larry is trademarked and Khan did not want to attract too much attention.  Like King's Quest above, the developer had to deal with the fact that the NES is controlled by a gamepad, not a keyboard (and the Famicom Keyboard does not count here).  I only played the demo but I washed a full playthrough on Youtube, so I can give impressions on what I have played and seen.


Larry is controlled by the D-pad and moves quite quickly across the screen.  The save/restore/restart menu is brought up by the select button, the inventory selection screen with the start button.  Button B uses the selected inventory item and Button A is a context sensitive button.  Button A is used to open doors, talk to people, take items, etc.  It is a very simple scheme but it does pare down the game to its bare essence.


As far as the port goes, some of the dialogue has been adjusted and areas like the alleyways, which only cause death, are not in the game.  As you can see in the attached screenshot, the graphics are plainer than the AGI version and there are fewer animated characters on the screen.  You can still die, for example, by walking into the street or having sex with the prostitute without protection.  The bar has been renamed from Lefty's to Tusky's.  In the casino, Blackjack has been changed to Roulette.


The game comes on a generous 512KB cartridge.  The cartridge has a 512KB of flash memory and 16KB of that is used to store a saved game.  Only one save game is supported, compared to twelve saves per directory for the PC version. The mapper 2 hardware this game uses is very common outside the flash saving.

The graphics have been taken from the AGI version, but the detail has been reduced.  There is much more in terms of music, but the Larry Theme is not present.  The music would not be out of place in a game like Bubble Bath Babes or Peek-a-boo Poker.  The closeups of the various girls you meet are also not present.  One last thing I must mention is that inside the box is a mail-in order form for Khan's port of E.T. on a NES cartridge.  The mail in order form is the only way to buy his E.T., so many collectors were unhappy that they had to open their sealed Larry box to buy the new game.  Just buy two!

Wednesday, January 21, 2015

Extra Sound in the Nintendo Famicom (NES) and Sega Mark III (Master System) and How to Get it Overseas

In Japan, Sega tried to compete with Nintendo's dominant console, the Famicom.  Among the benefits its 8-bit console, the Mark III, could boast were the ability to display more colors on the screen, a somewhat richer color palette, more built-in CPU and video RAM and a faster CPU.  On the minus side, the Mark III had no pause or select buttons on its controllers, a lower screen resolution and inferior audio.  The Famicom's 2A03 contained five audio channels (2x pulse, triangle, noise, PCM) to the Mark III's (integrated) TI SN-76489's four audio channels (3x square, noise).  Moreover, the Famicom's audio channels were substantially more versatile in hardware than the Mark IIIs.

Sega eventually released an FM Unit for the Mark III to help combat the Mark III's audio inferiority.  The FM Unit contained a YM-2143 2-op FM synthesis sound chip.  After it was released, most Japanese games would support both the Mark III internal audio and the FM Unit's audio.  Forty-one Japanese games supported the FM Unit.  Only eighty-six games were released in Japan for the Mark III.  When the system was re-released in Japan as the Sega Master System, the YM-2143 chip was built into the console.

Nintendo allowed for cartridges to contain extra sound chips. which could mix their audio with the internal Famicom audio.  The first product that did this was the Famicom Disk System, whose RAM adapter included an extra sound channel.  Seventy-five games for the Famicom Disk System are known to support the expansion audio channel, and about 190 games were released for the add-on.

After the fad for the Disk System had died down, other Nintendo licensees who has the license to make their own cartridges included audio hardware in some of their games : Konami, Sunsoft, Jaleco, Bandai, Jaleco, Namco(t).  Even Nintendo got in the act with its MMC5 chip.  Twenty-six Japanese games support some form of expansion audio.  However, approximately 1,055 cartridge games were released for the Famicom.  Fortunately, a list of every game and the chip they use and every disk game supporting expansion audio can be found here : http://wiki.nesdev.com/w/index.php/List_of_games_with_expansion_audio

Unfortunately, neither company thought it fit to allow expansion audio in the consoles released in the West.  The Nintendo Famicom sent its internal audio to the cartridge port.  Games without expansion audio would simply send this right back to the console, which then went to the output circuitry.  Games with expansion audio would take the audio from the Famicom, mix it with its own audio, and send the mixed signal to the Famicom's output circuitry.  When the Famicom was released as the NES worldwide, Nintendo re-routed the audio so that it did not go to the cartridge port.  Instead, a game could send its audio down one of the expansion pins in the middle of the NES connector, which would appear on a pin of the expansion port.  Then this pin could be bridged with a resistor on an adapter that connects to the port to a pin that provided access to the NES's internal audio, allowing for mixing.

The trouble was that Nintendo never released an adapter that bridged the necessary pins on the expansion port, so the functionality went unused. Additionally, Nintendo, which manufactured virtually all the boards for the NES, never released a board with expansion audio functionality except the MMC5 boards.  No other company, licensed or unlicensed, ever did during the NES's lifespan.  None of the games released for the NES using an MMC5 board use its expansion audio.

Using Famicom games on a NES requires the use of a pin converter.  Not all connect Famicom pin 46 (audio out) to any of the NES expansion pins.  Krikzz's pin converter connects Famicom pin 46 to NES pin 54, which is what the PowerPak and Everdrive N8 NES version use.

When Sega released the Mark III overseas as the Master System, it did not include the expansion port that would allow a user to connect an FM Unit directly.  In addition, the pin connector for overseas Master System cartridges is 50-pins and the Japanese (and South Korean) cartridges use 44-pins.  Sega did include a card edge version of the cartridge port on the back of the original Master Systems as an expansion port, but never released a peripheral that could connect to it.

However, Sega unintentionally was kind enough to make it relatively easy to add FM sound to an overseas Master System.  One resourceful hacker was able to recreate the FM unit as a board that plugs into the SMS's expansion slot : http://etim.net.au/smsfm/smsfm.html  Removal of a capacitor and soldering three wires completes the job.

Doubly fortunate for SMS owners, most US/European SMS games did not eliminate their FM Sound when they were ported over.  Some games were never released in Japan but still have FM sound.  The only games that removed the FM sound were Ys and Phantasy Star.  PS has a retranslation hack and Ys has a renaming hack to add it back in.  Some other games will require a code to enable FM sound, but most will use FM sound if it is present in the system.  Here are the list of games that support FM audio : http://www.smspower.org/Tags/FM

Of these games, Battle Out Run, Double Hawk, Dynamite Dux, Summer Games and Rambo III require patches to get the FM Sound working.  The available patches are for the Pro Action Replay, which is a device that patches RAM locations, not ROM locations.  The Pro Action Replay may be difficult to come by.  In addition, Wonder Boy III: The Dragon's Trap only gives FM music if it detects a Japanese Mark III or Master System but can be patched to always output FM music.  A real Time Soldiers cartridge will crash if FM sound is detected, a patched ROM will fix this issue.  The rest of the non-Japanese exclusive cartridges on that list should work in an FM-modded overseas Master System.

Approximately 114 games were released for the Sega Master System in the US, and of those 46 or so games supported FM sound, most (all but five) without any modifications.  That is nearly 50% of the games released for the system.  Europe received about 270 SMS games, and got nine more FM supporting games, but more require patches.  Still, compared to the NES, which did not receive many games that originally had expansion sound (eight cartridge games plus about eight to ten disk games), it is one thing SMS fans can boast about.

Tuesday, November 18, 2014

The Latest is not Always the Greatest

Atari 2600 6-Switch and 4-Switch vs. Jr.

Apparently many 2600Jr.s have a buggy TIA chip that causes Kool-Aid Man to be unplayable.  It is possible that it may affect other games, but Kool-Aid Man is confirmed.  See here :

http://atariage.com/forums/topic/165168-kool-aid-man-rom-problem/?hl=+kool#entry2950077
http://atariage.com/forums/topic/45244-why-does-this-2600-game-only-play-on-the-2600-jr/?hl=%2Bbuggy+%2Btia#entry547110

Unlike all 6-switchers and many 4-switchers, the chips in the Jr. are socketed and not easily replaceable.

Some Atari 2600jr. have a single chip instead of the three chips of most Jr.s and all other 2600.  They have video issues with the Harmony Cart's menu, and Kool-Aid Man and some interesting graphical anomalies with Pitfall II : http://atariage.com/forums/topic/196368-unicorn-boards-and-harmony-cart-menus-single-chip-2600-compatibility/

As far as the 6-switch vs. the 4-switch models go, the 6-switches (and the Jr.) have a video buffer chip that provides better video quality than the 4-switch.  Some cartridges or controllers may find it easier to fit in a 4-switch or a Jr. than the Light or especially a Heavy Sixer.

Atari 5200 4-Port vs. 2-Port

Not much of a comparison here, the ability to play four player games on the 4-port 5200 is balanced against  the ability to use the VCS Cartridge Adapter to play 2600 games on the 2-port 5200.  However, the 4-port 5200 can be modded with eight passive components to provide the required compatibility.  See Here : http://www.atarimuseum.com/videogames/consoles/5200/cx55.html

In addition, the 4-port 5200 uses a combination RF and power switchbox that is known for its fragility.  The 2-port uses a simple power adapter and separate RF output.  Fortunately, it is not too difficult to mod a 4-port for separate power and AV output.

NES - Front Loader vs. Top Loader

The Front Loader may have issues with its connector, but typically a good cleaning of the connector and carts a visual inspection of the pins can solve virtually any problem.  The Front Loader has AV out, which the Top Loader lacks.  Top Loaders are RF only.  In addition, the output on a Top Loader is crap.  A fix like this : http://www.stoneagegamer.com/nes-toploader-av.html would will restore the video quality, but you have to drill holes in your system's case or remove the RF unit.  Not a beginner's mod.

Also, Game Genies don't fit properly in a Top Loader.  There was an official adapter made for the Game Genie, but it is extremely rare.  You could use a NES PowerPak or Everdrive N8, which support five Game Genie Codes as opposed to the three codes of the real Game Genie.  Finally, there is no power LED on a Top Loader.

Sega Master System Model 1 vs. Model 2

Compared to the Model 2, Sega Master System Model 1s have a card slot in addition to the cartridge slot. The card slot let you play those games that shipped on a Sega Card.  It also is required for the Sega 3-D Glasses.  They also have an Expansion Port, which was unused officially but can be used for an FM Chip mod.  They have a port with composite video and RGB connections on the back whereas the Model 2 is RF only.  You can officially only play the Snail Maze game on early Model 1s, and the Model 2s lack the Opening Logo and Tune on startup.  There is no power LED or reset switch on a Model 2.

Genesis - Model 1 vs. Successors

The Model 1 is the only system which works as designed with the Power Base Converter.  While there are SMS adapters that fit in the Model 2, they do not offer a card slot.

Most Model 1s do not have the TMSS protection, which adds a second or two to the boot time of any game with the message Produced By or Under License from Sega Enterprises, LTD.  At least five US games will not work with TMSS Genesis machines.

There are two types of of Genesis Model 1s with TMSS.  One has the words HIGH DEFINITION GRAPHICS in white around the circle bordering the cartridge port.  The second omits the words.  All consoles with those words are widely considered to produce the best sound of all Sega Genesis models.  Some of the Model 1s without the text have a much poorer sound, it depends on the motherboard.  See here to find out how to determine the good Model 1s from the bad Model 1s : http://www.sega-16.com/forum/showthread.php?7796-GUIDE-Telling-apart-good-Genesis-1s-and-Genesis-2s-from-bad-ones The Sega Genesis Model 2s have variable sound quality, but none are considered to be as good as the Model 1s.

Model 1s have a headphone jack and use a power adapter with a plug that also fits into NESes, Famicoms and Sega Master Systems.  Model 2s omit the headphone jack but have stereo audio on their AV ports.

Game Boy - Original vs. Successors

The original Game Boy is larger than the Pocket, Light or Color.  It has larger buttons and a larger speaker and better quality audio.  There are games like Castlevania II : Belmont's Revenge and The Legend of Zelda, Link's Awakening which rely on the properties of the green LCD screen found in the larger Game Boy for certain graphical effects.  The Game Boy 4-player adapter does not require a converter.  Batteries last much longer in it than the Pocket or the Light.

SNES - Original vs. 1-Chip & SNES Mini

Most of the original boxy SNESes use a separate CPU and a two-chip PPU solution.  Late SNESes and all SNES Minis combine the CPU and both PPU chips into one large chip, called the 1-Chip.  While the graphics are slightly sharper than on earlier SNES models, some games suffer from graphical inaccuracies on the 1-Chip models, some games with enhancement chips run slower, some colors combinations suffer from ghosting and the whites are overly bright.  See here for more info : http://www.racketboy.com/forum/, go to forum called Guides under The Garage and look for the following thread, "SNES Console Revision Differences. SHVC-CPU-01 vs 1CHIP-Mini".

Playstation vs. PSOne

The PSOne is the slim version of the Playstation console.  It has a different looking menu for CD-audio playing, and a port for a matching Sony LCD.  But it looses the separate reset button, Serial and Parallel Ports, both of which have their uses, officially (serial for PlayStation Link Cable) or otherwise (parallel for Game Sharks).  It is harder to install a mod chip in a PSOne due to the tighter space.  There is an upcoming SD card solution for the Playstation called the PSIO which allows you to play CD backups from disc images, but it fits into the parallel port found on the SPCH-7xxx and lower, so no PSOne users need buy.