One Issue of PCjr. Magazine

Front Cover - The guy in the photo is shown at the beginning of the Dow Jones article, I think his expression is a double-take after seeing the prices for the service

In February of 1984, PCjr. Magazine was first published to highlight the new PCjr.  This magazine was published by Ziff-Davis, which had previously began PC Magazine in February/March, 1982, soon after the IBM PC's debut.  A friend of mine sent me a copy of PCjr. Magazine, Volume One, Number Eight.  I found the magazine easy to read and wanted to share some highlights of the issue.

This volume was dated for September, 1984, roughly seven months after the first customers had received their PCjr.s. (PCjr. was an "Early Bird Certificate" special for Christmas 1983).  It would cease publication by October of that same year, as reported in InfoWorld (which I consider something akin to the Annals of Computers).  The last issue was released in November, so only two more issues followed this one.  As the magazine is not available online, I would like to share some of the insights contained therein.  This magazine is extremely important because it reviews King's Quest in the issue. I will start with comments on specific ads and features which I find interesting by page number, and then make some general comments.

Fold-out Cover : Advertisement for the Tecmar jr Captain, a neat add-on sidecar with a parallel port, RTC and 128KB of RAM, expandable to 512KB.  Essentially all the good IBM sidecar upgrades rolled into one.  Tecmar also got the back cover.

Back Cover - Tecmar's Ad probably cost as much to print as it would have been to rent that ship.

Page 1 : WordPerfect, now available in jr. version.  WordPerfect was the successor of WordStar as the standard word processor for many, many computer users.

Page 10 : Impulse's Jr. Partner sidecar, similar to the jr Captain.  This advertisement implies that the sidecar can be upgraded using standard DRAM chips, all the way to 512KB.  It also advertises a bi-directional parallel port with a 16-bit timer.

Page 14 : AST's ad, "COMING SOON, New Products for PCjr."  AST made great stuff for the PC, but apparently decided not to follow through on their ad for the PCjr.

Page 15 : "Screen Play" Column.  He reviews Star Fleet I : The War Begins and Wizardry : Proving Grounds of the Mad Overlord.  Star Fleet is a descendant of the text-based Star Trek game of the 1970s.  The author begins with a mock conversation between Captain Kirk, Mr. Spock and Lt. Uhura from Star Trek, but Uhura's name is consistently misspelled "Uhuru".  He appreciated both games, but almost treated Wizardry like a new game, even though it had been a fixture of the Apple II computer for three years by that point.  (He did acknowledge that it had been popular on the Apple II for a while.)  He did not appreciate the merciless difficulty of Wizardry.  Apparently, the version of Star Fleet reviewed required Cartridge BASIC, as the system requirements indicate that version 2.0 would not.  Considering that Star Fleet was almost an entirely text-based game, this raises an eyebrow.

Page 17 : Microsoft's PCjr. Booster ad.  This sidecar included 128KB and a Microsoft Bus mouse.  The Booster sidecar's mouse offered an alternative to the serial mouse, and the PCjr. only had one general purpose serial port.

Page 18 : Atarisoft's games are featured in this ad.  Atari had released ports of several of its arcade licenses to the PC, and most of its games worked on the PCjr.  The games featured in the ad were Gremlins, Crystal Castles, Donkey Kong Jr., Mario Bros., Track and Field, Typo Attack.  Pac-Man, Ms. Pac-Man, Jungle Hunt, Battlezone, Donkey Kong, Centipede and Pole Position were also mentioned in the ad as still being available.  Only Ms. Pac-Man, Centipede, Donkey Kong, Moon Patrol and Typo Attack were listed as being available for the PCjr.  It appears that the later Atarisoft titles almost certainly added PCjr. compatibility.  Typo Attack was indicated as being released for the IBM PC/PCjr. and the Commodore VIC-20, but the latter version has been acknowledged to be vaporware, so I would suggest that the former is as well.  The game only appears to have been released for the Atari 8-bit computers.  Of the other games described in the main text, Atarisoft only released Gremlins for any platform, and it appears to work with the PCjr.

Promises, promises...

Page 19 : An article profiling Broderbund.  It identifies games like Alien Rain and Captain Goodnight. It also mentions famous games like Choplifter and Lode Runner.  Broderbund's contributions to the PCjr. were very limited.

Page 30 : Legacy Technologies's Ad.  Legacy marketed a line of expansions that sat on top of the PCjr. and allowed for a second floppy drive or a fixed disk drive.  Legacy's products also supported a unique L-bus expansion slot system.

Necessities come at a price

Page 33 : Ad for an obscure game called StarShip Valiant, which runs on the PC, XT and jr.  Also, in the next issue there will be reviews for Imagic's Touchdown Football and Sierra's Championship Boxing.

Page 35 : Feature evaluating and reviewing educational software and games.  Among the titles reviewed include IBM's Adventures in Math, which has graphics that look like those from the DOS port of Might and Magic, and the first version of Math Blaster!, which would enjoy a moderate notoriety in later years.

Page 47 : Photo of an IBM 5153 monitor on a jr., something IBM did not recommend.  The weight of the monitor would cause diskette drive errors due to the stress points placed on the case.  The 4863 can be put on top of a PCjr, without encountering this problem.

Page 51 : Ad for jr Connection, a software and hardware dealer.  Among the games there are several of Infocom's titles, Funtastic's Snack Attack II, Microsoft Flight Simulator 2.0, Orion's PC-Man and Sirtech's Wizardry.

Page 52 : Ad for Key Tronic's KB5151jr. keyboard.  The layout is like an early version of the first Northgate Omnikey keyboards, and  it uses capacitive keyboard switches, not the rubber domes of the IBM PCjr. keyboards.  There are separate function keys, arrow keys and a numeric keypad, and an attached keyboard cord.  $225.00.

Page 58 : Review of the Microsoft Booster sidecar.  Among the more interesting notes is a program that will move Cartridge BASIC into the expansion RAM, improving performance.  Newer versions of Flight Simulator (2.1+) can also use the mouse for controlling many of the program's features.

Page 66 : Review of King's Quest.  The reviewer describes the game as "the best use of graphics of any game yet developed for the PCjr."  He also notes that while the game makes use of the full graphics and sound capabilities of the jr. and was developed for it, a PC compatible version was already available.  He was impressed with the three dimensional aspect of the graphics.  However, he observes that the audio component is "barely adequate at best", failing to take much advantage of the "four-voice [sic] chip".

Is this for King's Quest or Pitfall II?

The reviewer praises the challenges for being "fun and fair".  Apparently he had not tried to guess the gnome's name.  He also notes that previous Sierra titles were more arbitrary and capricious with puzzle solutions.  He notes the procedure for creating a save disk and the replayability due to the scoring system and multiple puzzle solutions.  He really liked the game.

Page 72 : Advertisement for GATO

Page 77 : "Revue of Reviews", a feature recapping the reviews of the previous seven issues.  Among the games and educational software that had been previously reviewed were Facemaker, Fraction Fever, Juggles Butterfly, Type Attack, Adventure in Serenia, Casino Games, Conquest, Crossfire, Demon's Forge, Digger, Enchanter, Flight Simulator 2.0, Forbidden Quest, GATO, Infidel, Jury Trial, Micro Surgeon, Mine Shaft, Mouser, Murder by the Dozen, Sorcerer, Space Decathlon, Strategy Games, The Stud Poker Parlor, Styx, Tiao Ch'i (Chinese Checkers), and Ulysses and the Golden Fleece.  They reviewed the Legacy II in August, 1984.  They also reviewed the book Hands-On BASIC for the IBM PCjr. in that same month.

Page 88 : Short descriptions of products for the PCjr.  Includes the Rapport Drive Two Enhancement Package (later Racore), the jr-87 (allows an 8087 math coprocessor to be installed) and the jr extender (another 2nd drive + memory enhancement)

That is all the page annotations I found of interest.  I note that double-cartridge version of Lotus 1-2-3 had not been mentioned, so I would guess it hadn't been released yet.  VisiCalc and Microsoft Multiplan had been released for the jr. or could be run on it.  All the photos of the PCjr. in the magazine show the chicklet keyboard, which IBM recalled and replaced in July.  Apparently the magazine and the vendors had not appreciated the urgency of eliminating that unwelcome image from their artwork.  This is one area in which all companies concerned should have taken more aggressive action to shed the poor PCjr. image with its useless chicklet keyboard.

Most of the games reviewed in the magazine had no special (Wizardry, Enchanter, Juggles Butterfly) or marginal (Crossfire, Mine Shaft) PCjr. support.  Adventure in Serenia was released very early for the IBM PC, and according to an IBM brochure I have, it was not updated for the PCjr.  The only box I have seen for it is the old clam-shell style IBM used for early PC software, not the later large "cassette tape" boxes.  There was a later obscure re-release of the game for the PCjr. under the title Wizard and the Princess, but I doubt it would have been available at launch.  "Casino Games" may or may not have been the IBM title, the game is attributed to the generic "PC Software Corporation"

The magazine reviewed three games from Windmill Software, one of the earliest companies to focus exclusively on the PC platform.  The PC versions of these games tweak the CGA far too much to be playable on a PCjr., so special versions must have been marketed.  There is cover artwork for Styx on MobyGames indicating that it was for the IBM PCjr.  It is unknown if there are any enhancements for the PCjr. versions of these games, but nothing I read leads me to believe otherwise.

Of the canonical eight cartridge games, the magazine had reviewed four of them.  The reviewers probably like those games more than I do.  I like the other four cartridge games comparatively better.

GATO does not appear to have any PCjr. enhancements, but apparently there was a later version which added 16-color support for Tandy 1000s.  This required 256KB, whereas IBM PCs with CGA and PCjr.s only required 128KB, so no 16-color graphics for PCjr. users.  Demon's Forge received a PC port well before Mastertronic's 1987 release, so perhaps the PCjr. has official 16-color support.  I have a hacked version of the hard drive hack which restores 16-color support for all Tandy 1000s and the PCjr.  Apparently this version was released by Boone Software, which did re-release the Apple II version under its brand.

Hardware-wise, it is amazing how quickly other companies reacted to plug the gaps in IBM's machine.  More than one option was available for adding a second floppy drive and many memory expansions were available.  A better keyboard was available as was a math-coprocessor adapter, and you could even add a hard drive if you were prepared to spend a lot of money.

The magazine implies that Hands-On BASIC for the IBM PCjr., published by IBM did not come with the computer, I have verified that it did..  The BASIC reference manual presumably came with Cartridge BASIC, which was a separate purchase.  The only other substantial documentation included with the system would have been the Guide to Operations.  The DOS manual came with DOS 2.1 for the PCjr., purchased separately.  The Technical Reference and the Hardware Maintenance and Service Manuals were also released separately.

Arcadia/Starpath Supercharger - Cassette Games on Consoles

The Arcadia/Starpath Supercharger for the Atari 2600 was a very peculiar device from the second generation of video games.  It was a very large cartridge that plugged into the 2600's cartridge port.  It contained 6K of S-RAM for loading games off cassette tapes and 2K of ROM for the loading code.  The Supercharger was packaged with the game Phaser Patrol.  The initial cost of acquiring the Supercharger was higher ($44.95) than a standard 2600 cartridge ($29.95 for many new titles), but the games themselves were often priced lower than cartridge games ($14.95-17.95) due to the use of cassettes, which were much cheaper to mass produce than cartridges. Not included in that price was the cost of the cassette recorder, which the player had to supply.  The cassette recorder's line out would be connected via the Supercharger's audio cable.

Ten games were widely available during the accessory's life, two could be purchased by mail order, and four prototypes are known to exist.  Among the Supercharger's best games were Dragonstomper, one of the first console RPG games.  Communist Mutants from Outer Space is a fun shoot-em-up in the Galaxian vein, and Fireball is a fun Breakout clone.  Escape from the Mindmaster uses a very impressive first-person perspective.  Even though the library is small, the overall quality of Starpath's 2600 games, in my opinion puts the company in the first rank of 2600 game designers alongside Atari, Activision and Imagic.

I must give special mention to the version of Frogger released for the Supercharger.  This version, the so-called Official Release looks, sounds and plays far better than the Parker Bros. cartridge. In fact, it is superior to just about every cartridge release of the game.  The arcade original has five lanes of roads and five lanes of water, but many console ports only give you four road lanes. Even more impressive is the fact that the arcade music plays throughout as it should despite the rather humble audio capabilities of the 2600. Many ports cut the theme short and leave you with silence during most of the gameplay.  The SNES version is particularly atrocious in this regard because it has no music at all!

When the Supercharger was inserted into the 2600 console, the screen would show "REWIND TAPE PRESS PLAY".  Once the player did that, the game would proceed to load, with colored bars on the screen closing in informing the player of the progress of the load.  When done, the screen would display "STOP TAPE" for a moment, then the title screen of the game would appear and the player could start playing.

Most games were fully loaded within one load of the cassette, but four games (Dragonstomper, Party Mix, Survival Island, Sweat! - The Decathalon Game) used three loads and one (Escape from the Mindmaster) used four.  The tape would be rewound to the beginning, then the first load would start the game, requiring the player to stop the tape.  When the game needed the next load, the player would have to start the tape again.  If he waited too long in stopping the tape, he would have to rewind it and play it until the game found the beginning of the right load.  A load may take approximately 20-40 seconds, depending on the game and which side of the tape was being used.  Side A was the fast-load side, Side B was a slower load if Side A did not work with the player's cassette recorder.

The Supercharger digitized the binary data of a game onto an audio cassette.  A "0" bit would be an audio wave pulse of 158ms and a "1" bit would take 317ms (fastest speeds) or 900ms/2450ms (slowest speeds).   The controller chip in the Supercharger would use an ADC to convert the audio into binary data for the RAM.  The Supercharger supports three banks of 2KB of RAM and one bank for the 2KB ROM.

People talking about the Supercharger often state that it increased the RAM capacity of the 2600 (128 bytes) 49-fold.  This is not really an apt comparison.  An average cart uses a 4KB ROM chip to store program code, graphics and sound.  That data must be stored in the Supercharger RAM.  A Supercharger game is really like a 6KB cart (with a single load game, otherwise 18KB/24KB cart).  However, any portion of that 6KB can be used as extra RAM.  Each load of a Supercharger game transforms into an 8448 byte binary file, but that file includes a good deal of space not used by the game (including the space occupied by the ROM bank and a header).  Additionally, all ten of the officially released Supercharger games include a "demo" load at the end of the last game load on the tape to show previews of other games.  For multiload games, a combined binary file is used with emulators and cartridges like the Harmony Cartridge.

Comparatively, 8KB, 12KB, 16KB and even a 32KB cart were released during the 2600's lifetime.  The three 12KB carts from CBS came with 256 extra bytes of RAM, and sixteen of the 8KB, 16KB and 32KB carts from Atari came with 128 bytes of RAM.  One game from M-Network, Burgertime, used 12KB of ROM and 2KB of RAM.

The Supercharger was not the only 2600 peripheral that could utilize cassette storage.  The CommaVid Magicard programming cartridge came with 2KB of ROM and 1KB of RAM.  There were instructions in the manual to modify the cartridge to add support for saving and loading programs to cassette.  The Spectravideo Computmate came with 16KB of ROM and 2KB of RAM.  The Compumate turned your 2600 into a cheap computer as it came with a 42 key membrane keyboard that would fit on the front grill of a pre 2600jr. machine.  It supported saving and loading programs from cassette using a standard cassette recorder.  But the impact of these devices pales in comparison to the Supercharger and its games.

Game Boy Pocket - The Pure Monochrome Experience

I have recently acquired a Game Boy Pocket.  It is one of the revised models, with a blue case and a power LED.  The Pocket is a slimmed-down version of the original Game Boy.  Its chief benefit is that its case is smaller and less bulky.  It has a similar screen size but slightly smaller controls and speaker.  It plays the exact same titles as the original Game Boy.  It doesn't have a backlight, but one can be added today with mods.

The screen is the best feature of the Game Boy Pocket.  It has better contrast than the original, a better monochrome gradient and virtually no ghosting with moving images.  The original Game Boy screen, due to pixels with long transition times, would show ghosting in moving images. Some games have effects that require a monochrome screen, like the mountains at the beginning of the Cloud Castle stage in Castlevania 2 : Belmont's Revenge.  On any color screen, the mountains will flicker more than on a monochrome screen.

When I play a game on the original Game Boy, I have asked how I ever put up with that awful screen when I was a child.  I do not ask the same thing about the Pocket.  Another plus to the Pocket is that it does not suffer the missing vertical lines issue of the original Game Boy screen (fixable, but still).

The sound has been criticized as not being as nice as the originals', and from the headphone jack there an annoying background noise that is audible when headphones are connected through the headphone jack.  The original Game Boy just has hiss.  Stereo panning support was a touted feature of the Game Boy when first released, but by the time the Game Boy Pocket was released in 1996, there were few music and sound effects in games that supported stereo sound.  Most people used the built-in speaker, even when headphones could be used.

The controls on the Game Boys and Game Boy Advance feel like real D-pads, the controls on the Game Boy Advance SP feel more like microswitches.  The controls on the Pocket are not so much smaller than the original to really feel like you have lost precision control.

Backlighting kits exist for the Game Boy Pocket, typically kits work for the original and the Pocket.  The best ones are from nonfinite electronics and kitch-bent.  Installing a backlight in the Pocket is a bit trickier than in an original Game Boy, here is a good video showing how it is done : http://www.youtube.com/watch?v=qUUEVWbLoS8  A Youtube channel now called 8-bit guy suggested spraying WD-40 into the crevice between the layers and the glass once you have pulled up a corner.  He says this really helps remove the adhesive bond.  Having irreparably damaged a Game Boy Pocket's screen after trying a mod without WD-40, using WD-40 may be a good idea.

The only real disadvantage to the Pocket is its anemic battery support.  The original Game Boy uses four AA batteries, and the Game Boy Light, Color and Advance all use two AA batteries.  The Pocket uses two AAA batteries.  An AAA battery has about half the rated mAh as an AA battery.  While this is OK for playing official cartridge games without a backlight, it is far from ideal for using multicarts like the EMS GB 64MB Smart Cart or the new Krizz Everdrive GB.  A backlit GB requires more power than a non-backlit GB, even with modern LED backlighting.  Multicarts require more power than standard carts

In my opinion, Alkaline batteries may be okay for a backlight, but they do not have sufficient power for a multicart.  On the EMS card, the cart may work for a while with fresh, name-brand batteries, but after a short time they will not be able to power the card, which will lead into an endless reset loop.  Alkaline batteries experience a far greater mAh drop over use than Lithiums.

Perhaps the EMS cards made after June, 2010 (as shown on the back of the card, mine is 0908) are better with this.  More active screens will appear lighter than less active screens.  NiMH batteries tend to support 500-800 mAh compared to the 1250-1000 mAh of the Energizer Ultimate Lithiums.  1000 mAh average is probably the maximum you will get out of name brands, but I hear they can provide a much more reliable current than an Alkaline.  I would strongly recommend using the Sanyo Eneloops or other high end brand.

There are AC adapters for the Gameboy Pocket.  The right adapter for the Pocket or the Color uses 3V, 300mA and has a positive tip.  Radio Shack's Adaptaplug A should fit.

My EverDrive GB will work in my Game Boy Pocket with Sanyo Eneloop rechargeable AAAs.  The screen contrast will lighten somewhat when it is loading or flashing a game, but it will complete the process.  When the game is playing there will be no need to constantly monitor the contrast dial as I would with the EMS Flash Cart.

Ron Gilbert, Maniac Mansion and Modern Computer Adventure Game

Ron Gilbert may not have a huge number of adventure games (not for children) to his credit, but his influence in adventure gaming far surpasses the number of games on which he was credited as designer.  He has two bona-fide classics to his name, 1987's Maniac Mansion and 1990's The Secret of Monkey Island, and I would also include Monkey Island 2 : LeChuck's Revenge as a classic.  In this post, I want to talk a little bit about why his first game, Maniac Mansion, is a classic, both from a design perspective and and a thematic perspective.

In Sierra's games, Death is your ever present companion.  He lurks on most screens, ready to frustrate the player who forgot to save within the last five minutes.  In Gilbert's Maniac Mansion, death is possible but its more of an accomplishment to kill one of your characters.  How to figure out another way to kill a character is really akin to solving a puzzle.  And the ways in which you can die are reasonable and make sense in the context of the game.  If you let the reactor go uncooled for too long, there will be a meltdown.  If you show Weird Ed his dead hamster (which can only be killed by certain kids), he will kill you.  Since you have three kids, you may still be able to beat the game if one dies.  In both King's Quest V and Leisure Suit Larry, there are screens that if you enter them, you are guaranteed to die due to a monster or there is a monster there every time ready to kill you.

The worst you can typically expect in Maniac Mansion

Another lazy design issue in other adventure games is putting the game in an unwinnable state.  Typically this is because the player forgot to pick up an item or do something at a timed event and now can no longer do it.  This is a poor way to extend the gameplay and increase the challenge because it is so unfair.  It is difficult to get Maniac Mansion in an unwinnable state unless you are truly careless.  Leisure Suit Larry 2 is particularly cruel in this regard, in more than one part of the game if you fail to do everything you need to do before a time limit, you will lose the game.   

A third, truly lazy design choice in adventure games is the use of maze-like environments.  These were amusing when Zork was king, but Sierra was using them to obnoxious effect twice in King's Quest V. Maniac Mansion has no mazes and no generic or featureless screens.  Each screen has at least some visual interest, and most contain either an item or is part of a puzzle.  In the later Monkey Island games, the maze-like environments were just another puzzle to be solved.

I'm not sure how accurate that map is, but that is the rough number of rooms in the game.

Even so, Gilbert encouraged exploration of the mansion at the player's leisure.  Although the game may seem to have a limited time, this is not the case.  No matter how long you take, the meteor will not possess Sandy.  Only during the end game does a timer countdown.  In the ICOM simulations like Shadowgate and The Uninvited, there always was some limiting factor in the game like the number of torches available or that you will be possessed.  

Random monsters are no fun.  Sierra used them not only to kill but also to cause an unwinnable game state.  If the Dwarf steals one of the three treasures in King's Quest, you cannot win the game.  In Maniac Mansion, the "monsters" have fixed schedules and locations, and at worst they inconvenience you.

The scheduling and cutscenes in the game help to show that this game is a living, breathing world.  In most other games of the time, the game simply reacts to what the player does.  Here cutscenes propel the story forward.  The various actors in the Mansion have clearly defined characteristics, Weird Ed is a commando, Nurse Edna is kinky, Green Tentacle is a wanna-be musician, etc.  The large sprites used for the characters help give each kid and character a unique look.  The heads are big enough to allow for the graphics engine to show them talking, which helps with the immersion.

If this was a Sierra game, the Green Tentacle would have killed you here.

Another terrible design issue is the use of obstacles that you have to climb or cross very carefully.  Stairs in the King's Quest series are serious obstacles, especially in II and IV.  The rock path from Mannanan's house in III is particularly evil.  The whale's tongue in IV is no fun, but the Waterfall Cave must have been designed by the development team after an all-night office party.  Not only is there a random monster, who follows you from screen to screen, the cave is dark and the lantern sheds little light.  Finally, there is a pit you have to cross, and you can easily die trying to find the edge.  Nothing like that exists in any LucasArts game.  In fact, Maniac Mansion includes pathfinding and indirect control of the character by cursor, something that would be ubiquitous in the 1990s.

Gilbert believed the text parser interface to be truly archaic for graphic adventure games.  He despised trying to play "try to guess what the designer wants you to type".  While Maniac Mansion was not the first game to use an icon-based interface, it firmly put paid to the notion that adventure games would be too easy without the text parser.  Although the icons are words, not graphics, nonetheless they serve the same function.

The graphics in the original Maniac Mansion are in a low, 160x200, resolution.  To avoid any need to "guess" what an item is, Maniac Mansion had a "What Is" command that if the pointer hovered over the object, the game would tell you what it is.  In fact, using the What Is command allowed you to identify all the "hot spots" in the room.  Early Sierra games had no generic "look" command, but eventually their AGI games would generally tell you what was important in the room.  The later 16-color SCI games allowed a right click on the mouse to function as a "look at" on the object clicked on. 

Maniac Mansion was one of the first adventure games intended to be replayable.  The different combinations of kids allowed the game to be won in more than one way.  There are also multiple endings, and each combination can access some of the endings.   This helped make up for the relative smallness of the game world.

Choices, choices...

Maniac Mansion is a "funny game".  Funny games are memorable.  Really humorous characters tend to be more memorable over the long run than bland or serious characters.  A goofy 8-bit mansion is more likely to be iconic than a "realistic" 8-bit castle and more memorable.  Games that aren't mean to be taken truly seriously tend to hold up better than a lot the portentous, supposedly-meaninfgul crap of the 1990s and 2000s.  It is also easier to be funny than dramatic on less capable machines.

Gilbert deserves credit for developing Maniac Mansion for the Commodore 64.  The final game shipped on one double sided diskette (340KB) and could be run within the 64KB of RAM of that system.  By contrast, Sierra's AGI games in 1987 took up at least two disks (360KB) and required twice the RAM on an Apple IIe/IIc and four times the RAM on a PC (they didn't run on a Commodore 64).  To be fair, the ports of Maniac Mansion to those systems required the same amount of RAM on the Apple IIe/IIc and PC.  The opening music was unusually good for a US Commodore 64 game, something lost in the Apple & PC versions (except on a Tandy 1000).

Vintage PC Game Music - Supporting as Many Early Music Devices as Possible

Music in PC games existed before the 1990s.  First there was the PC Speaker, then PCjr. and Tandy 3-voice sound, next came expansion boards like the Adlib and Game Blaster and supported MIDI devices like the MT-32, and finally the Sound Blaster.  My goal is to combine as many of these devices as practical in a single system.  Since the PC Speaker is ubiquitous, the choice of systems seems unlimited.

Of the other devices, Tandy 3-voice sound first was supported in games in 1984 (PCjr.), and sound cards and MIDI devices first were supported in late 1988.  However, the need for Tandy 3-voice sound limits the system to a Tandy 1000, since that chip was never implemented in a compatible ISA card.  Additionally, only a Tandy with 8-bit slots and Tandy video should be considered, since modifying either gives real compatibility problems.

As I have previously indicated, the Tandy 1000 TL and the TX are the best candidates here.  The TL/2 and TL/3 are not as good choices because they have one fewer slot than the older machines.  That slot is better used by an ISA or SCSI interface that can interface to a hard drive.

The TL has a PSSJ sound chip which includes 8-bit digitized sound capabilities.  It can support up to a 44KHz sample output rate.  The Sound Blaster 1.0-1.5 only support a 23KHz sample output rate, but the 2.0 supports a 44KHz sample rate.  The PSSJ and the Sound Blasters work similarly and both use IRQ7 (selectable, but early games insist on 7) and DMA1 (cannot be changed or fully disabled) and tend to crash when the other is present.  They will not coexist happily in the same system, and there is nothing that can be done about it.

While the PSSJ may look better than the Sound Blaster for digital playback, there are two additional issues to consider.  First, early games with digitized sound are not going to playback samples at 44KHz because they take up so much disk space.  Even then, samples tend to be short, so any playback differences are not likely to be noticeable. More importantly, games using the Sound Blaster for digital playback will accept gameport input, games using the PSSJ will not during sample playback.  If there is a good deal of sample playback, like in Outrun and Prince of Persia, the joystick will not work at all.

The TX doesn't have the PSSJ, therefore the Sound Blaster is the sound card with the best digitized support from early games.  The Sound Blaster includes the Adlib chip and can easily include the Game Blaster chips for a few dollars.  However, the TX has a built-in gameports that cannot be disabled, so the Sound Blaster's gameport will have to be disabled.

On the TL, separate Adlib and Game Blaster boards will be required.  I am not so comfortable suggesting a Sound Blaster Pro because many games supporting Game Blaster will only write to I/O 220-223, and that is where the OPL2 chips are located on a Sound Blaster Pro.  Similarly, many early Sound Blaster games will only support the Sound Blaster at I/O 220-22F.  While a non-upgraded Sound Blaster will not cause trouble at I/O 220-223, it uses the rest of the I/O ports and the Game Blaster also uses those I/O ports for autodetection.

Additionally, an MPU-401 interface card will be required, few games support the Sound Blaster MIDI interfacer.  There is a driver to allow most Sierra games to work with the Sound Blaster MIDI interface. With the MPU-401, you can connect to the MT-32, the FB-01 and the Casio devices supported in Sierra and Accolade games.

Therefore, on the TL, three cards are devoted to sound, and on the TX there are two.  In my ideal system, one bay should be used for a 5.25" drive, and a second bay for a 3.5" drive.  A TL has an extra bay for a hard drive, and the TX may require a slot-CF adapter, otherwise a bay or a hard card will be required.

Practical Issues with the Tandy 1000 SX and TX

I have recently become the owner of a Tandy 1000 TX, and I'd like to share my experiences with using the machine.  Since the system is very similar to a Tandy 1000 SX, much of what I will say will also apply to that system.  Overall, the system is much more straightforward than the Tandy 1000 TL.

Memory Upgrade  (SX and TX differences)

The TX comes with 640KB but can be upgraded to 768KB.  The extra 128KB is dedicated solely to the video chip and allows you to have the full 640KB conventional free for MS-DOS.  There are four DIP-18 sockets on the motherboard, and you must insert a 64Kx4 DRAM chip, 120ns or better into each of them.  Once all four are inserted, you must remove the jumper at E9-E10.

Not all games and software work with this upgrade.  I know of three games that either do not show graphics or are unplayable (Demon Stalkers, Snow Strike, Duck Tales : Quest for the Gold) with the upgrade. Unlike the TL, you do not need to remove the chips.  Just replace the jumper at E9-10 and the upgrade will be disabled.

The SX comes with 384KB and can be upgraded to 640KB.  Eight DIP-16 sockets are on the motherboard and you must insert a 256Kx1 DRAM chip, 150ns or better into each of them.  One all eight are inserted, remove the jumper at E1-E2.  There are no compatibility issues with this upgrade.

If you add an EGA or VGA card, the on-board video and its RAM stealing is disabled and you will also be able to use the full 640KB of conventional memory.  Most games will not recognize an EGA or VGA card in the Tandy 1000s without running a simple program called VGAFIX on startup.

Case Opening (SX and TX differences)

The SX and TX's case is held together by two screws at the front.  The case shell is made of plastic, so be careful of stepping on it or letting it fall when you are working inside it.  Unlike the TL and SL and later machines, the keyboard and joysticks attach to the front of the machine, so you will need to remove them to get at the insides.  When you have removed the front screws, just pull the plastic portion of the case forward.

Unlike the SX, which had a metal bar over the expansion slots to allow a monitor to sit on the case, the TX has a metal shield completely covering the expansion bays.  Two screws attach the shield to the chassis, and once removed, you have to pull the shield up and then to the left.  You may need a small screwdriver to help pry it up.  The shield is bendable, so take care with it.

The SX has a metal bar to support the weight of a monitor, and should have two plastic guards to protect someone from slicing their fingers on the metal edge.  Its expansion slots use slotted hex screws.  The back plastic plate should be removed when installing expansion cards, but one can get at the screws with a small slotted screwdriver.

Tandy mostly used slotted or phillips head hex nut screws inside the SX and TX, and I highly recommend using a 1/4" hex nut driver to remove them.  You won't strip a screw using a hex nut driver.  The drive cage is fixed to the chassis with approximately five screws.  You will need to remove any expansion cards to get at the screws.  The SX has a metal plate parallel to the the expansion slots that should be removed to get at some of the screws holding the drive cage in place.

The TX and TL use the same small Phillips head screws for the expansion cards.  Jameco sells compatible screws, look for Jameco Item # 2185871.  Unlike the SX, you probably will not need to remove the back plastic plate to unscrew the screws.  They also work in the SX.

The drive cage supports only two 5.25" drives.  Some drives do not have the appropriate mounting holes.

CPU Upgrade (TX and SX differences)

The TX, like the TL, has a socketed 80286-8 in an 68-pin PLCC socket.  Unfortunately, the location of the 286 is close to the front edge of the bezel, and a longer accelerator will not fit.  Improve Technologies Make-it-486! will fit, but it has no math coprocessor.

The 80287 math coprocessor should be rated for 8MHz, but a 6MHz will probably be fine.  Games that run on an 8MHz 286 generally do not use one.  No jumpers or dipswitches need be set.

The SX has a socketed 8088-2 in a 40-pin DIN socket.  It can be upgraded with an NEC V-20, μPD70108-8 for a modest speed boost and compatibility with many programs that use 286 instructions.

The SX will support a special accelerator board called the 286 Express Card.  This card takes up an expansion slot, requires the removal of the 8088 and inserting a ribbon cable with a DIP-pin connector into the CPU socket.  The 8088 goes onto the daughtercard with the ribbon cable.  This upgrade allows and defaults to the use of the 8088 and acts like it is not there unless activated via its DOS driver.  It has 8KB of cache, which can be disabled for compatibility.

The 8087 math coprocessor should be rated for 8MHz operation, but 5MHz will probably be fine (its runs at 7.16MHz/4.77MHz).  Remove the jumper at E3-E4 if you install one.

Floppy Drives (SX and TX differences)

The ideal 5.25" 360KB double density floppy drive for the Tandy 1000 SX or TX is the Teac FD-55BR. This is a beige/off-white version of the FD-55BV, which is also a good choice.  Teac made a 1.2MB 5.25" high density drive called the FD-55GFR, and it looks identical to the lower density drive.  Make sure you get a double density drive, high density drives do not work with the SX or TX's built-in floppy controller.  The SX and TX have very short floppy cables and the card edge placement on the Teac drives (and they are good drives) work beautifully with the stock cable.  The molex power connector is also close to the left edge of the drive, and the one connector from the power supply is extremely short.

The proper drive to use with a TX  is a Sony MP-F63-01D 720KB double density 720KB floppy drive.  This drive is a 3.5" drive enclosed in a 5.25" bay adapter.  The bay adapter provides the front faceplate for the drive.  The drive uses a large "lip" as the ejector button.  It is identical to the drive in the HX, but that has a different faceplate and designation.   Tandy provided a 3.5" upgrade for the SX that uses the same drive but has an adapter board that converts the power-in-drive connector on the drive to a card edge and molex connector.

The TX and HX are the first systems that incorporate Tandy's power-in-drive cable, so you need to use your own cable with holes punctured through pins 3, 5, 7, 9, 11, 29, 31, 33 if powering a 3.5" drive that uses a mini-molex power connector.  You also need to untwist the twist in the floppy cable.  Tandy drives get selected by dipswitches and the F3 key in the SX and TX.

The TX cable has one pin connector and one card edge connector.  The SX has two card edge connectors. The SX does not use power in drive cables and has two molex power connectors.

Hard Drives (SX and TX)

The SX and TX requires a hard drive interface.  An MFM controller like the WD1002A-WX1 is small enough to fit in the Tandy and can select IRQ2, but you may need to obliterate a trace that hardwires IRQ5.  However, the SX and TX can disable the video's use of IRQ5.  The hard cards sold during or near the TX's time were were the 20MB 25-1029(A-B) and 25-1032(A-E) and the 40MB 25-4059(A-B).  They use MFM or XTA-IDE drives.  They can save a slot, but are bulky, noisy and can prevent long cards from being installed in nearby slots.

The best contemporary IDE interface was the ADP-50L, which allows the use of any 16-bit IDE drive up to 504MB.  With a compact flash adapter, you can save a drive bay by using a slot bracket.  Modern solutions include XT-IDE, some of which combine a CF card interface, saving you a slot.  Unfortunately, while you can buy the board and parts cheaply enough, you will have to solder the CF connector and other surface-mounted components yourself.

Serial Port (TX only) / Light Pen Port (SX only)

The TX replaced the useless light pen port on the SX with a serial port.  This is a standard XT-8250 port, so do not expect speeds about 9,600 baud.  It defaults to COM1 and can be set to COM2 by removing the jumper at E3-4 or disabled by removing the jumper at E1-2.

The SX uses a DE-9 Male no-screw connector for a light pen, which would suggest that Atari 8-bit or Commodore 64 light pens would work.  The pinouts for those light pens do not correspond to the pinout for the Tandy 1000.  Tandy did offer light pens for the 1000 series, but they must be beyond hard to find today.

Jumpers (SX and TX)

JP1 sets the system to use an MDA or Hercules compatible card.  I am not sure whether it totally disables the onboard video, or just initializes the monochrome monitor for text like on an IBM PC.  If its the latter, programs can still use the built-in video when they require it.  It is NOT the same as pressing F1 on startup, that just sets the Tandy video to use composite-monochrome friendly colors.

JP2-5 disables the use of IRQ5, 6 & 7 for the system board devices, freeing them up for the expansions slots.  The system board uses IRQ5 for the video interrupt, which was rarely used with Tandy graphics.  IRQ6 is used for the floppy controller.  Even if you disable the built-in floppy controller's IRQ6, you will need a secondary floppy controller that can use an alternative floppy controller address.  Ditto for a printer port on an expansion slot for IRQ7.  Leaving IRQ7 enabled is typically harmless.  Sound Blasters don't need it disabled.

Keyboard (SX and TX)

The SX and TX is designed to use a 1000 keyboard.  Some games (Snow Strike) and programs, like Tandy 1000 Deskmate, require it.  The default text mode is an 80x25 column by line mode with 225 lines, pressing F2 at startup will give you a 40x20 column by line mode with 200 lines, suitable for a composite video monitor.  You can also do this by using the Tandy DOS 3.2 or 3.3 command MODE TV If you use the command MODE 200 command will give you 80x25 column by line mode with 200 lines (assuming you are in an 80-column mode).

F3 sets the speed to 4MHz (TX) or 4.77MHz (SX), which can also be done with MODE SLOW.  If you want to play a game like Lode Runner on the TX, you will need the slower speed.  F4 swaps the boot drive, which is quite useful with a 5.25" and a 3.5" drive.

I am not the biggest fan of the 1000's keyboard.  The key action is mushy and the Shift keys are too small.  The Hold key is a particular nuisance, especially as it is right next to the Enter key.  Essentially it is the "freeze" key, if you press it (intentionally or otherwise), your program may pause and it may seem like the computer has frozen up and crash.  Press it again and the program should resume.  Shift + Print acts acts to Print the screen (I believe its Ctrl Print on a IBM PC).  There is no Scroll Lock key, you need to use Alt + Break.

Some programs will only use the dedicated cursor keys for movement, others will use both the cursor keys and the numeric keypad, and others will only use the numeric keypad.  On the IBM PC 83-key Keyboard, there is no dedicated cursor keys, and games do not have this problem.  However, unlike that keyboard, there are status LEDs for Num Lock and Caps Lock.

The ~ and ` and the | and \ are split up on the Tandy 1000 keyboard, making for an adjustment when coming from a PC keyboard.  The \ key is used frequently in DOS, and the | is also used.  (TYPE README.TXT |MORE) More annoyingly, there is no separate *, so typing something like *.* in DOS is a hassle.

Any Northgate Omnikey Keyboard with dipswitches should be able to work with an SX or TX.  They are very expensive, and required a special cable.  I believe the cable just passively mapped the common pins (DATA, CLK, +5v and GND) from the IBM standard to the Tandy standard.  The Northgates can provide full 101 Key capabilities.

Sound Output (SX and TX differences)

The SX and TX both have volume controls for the internal speaker.  The SX's volume control is inside the case and requires opening the case to get at it.  The TX's is in the front of the case and can be accessed with ease.  Both have RCA video and audio jacks, but the TX also has a headphone jack.  Due to the audio routing design of the TX, all audio will always output to the RCA jack.  If something is plugged into the headphone, the internal speaker is disabled.  The volume control will still work for the headphones, but has no effect on the RCA output.

On the TX, there is no need for a program like TDYSPKR to set the internal and external audio options. On the SX, you will need that program to hear 3-voice sound out of the RCA jack for games that do not set the multiplexer (LucasArts' SCUMM games) or to shut off the internal speaker.

Apple //c vs. IBM PCjr. - Clash of the Computer Titans, 1984

Two compact machines, with limited or very limited expansion were released by two titans of the Industry in 1984.  The IBM PCjr. and the Apple //c were both heralded with great fanfare and greeted with great initial enthusiasm.  However, the PCjr. failed within a year and the Apple //c was generally seen as a poor man's Apple IIe.

Input

The Apple //c has a built-in keyboard, but it contained all the keys of the Apple IIe, plus an 80/40 column switch.  The PCjr. supported a wireless keyboard with 21 fewer keys than an IBM PC keyboard.  There were substantial compatibility problems with the PCjr. keyboard interface when programs were intended to run on a PC.  There were some minor compatibility issues with programs expecting the older keyboard.  The PCjr. keyboard uses rubber domes, while the //c uses scissor-keyswitches like a laptop.  While expensive, it is possible to replace the PCjr. keyboard with a nicer keyboard with more keys.

The PCjr. supported two joysticks with two axes and two buttons each.  The Apple //c only had one joystick port, which supported one joystick with two axes and two buttons.  The joystick port was also used for the mouse.  A PCjr. required a serial mouse or a bus mouse.  The PCjr. also supported a light pen.

Advantage : Apple //c (out of the box)

Storage

The PCjr. was only designed for one floppy drive, but that drive was a doubled sided drive supporting 360KB disks.  A second drive required an expensive expansion.  The Apple //c used the standard Apple II single sided disk drive supporting 143KB per side.  However, there was a port in the back of the machine for a second drive, no extras required.  The PCjr. Diskette Controller and BIOS relieved much of the burden from the programmer and CPU of reading and writing to the disk.  The Apple //c's drive controller (for 5.25" drives) is an integrated version of the TTL-logic based Disk II controller, so pretty much all reading and writing is done via software.  Even without factoring in the disk flipping, the PCjr.'s diskette drive was easier to use.

The Apple //c, with a ROM upgrade, could also support a UniDisk 3.5" drive for 800KB 3.5" disks.  The UniDisk was an intelligent drive to compensate for the slow CPU of the Apple IIe/IIc and is a pricey upgrade these days.  The IBM PCjr can use a 720KB drive or most common 1.44MB drives (with 720KB read/write capabilities) if you use DOS 3.2 or better.

The PCjr. supported a cassette interface for saving and loading programs from BASIC.  Even though all previous Apple II models supported the cassette interface for saving and loading in BASIC, the Apple //c dropped the cassette jacks.  The cassette interface was intended for the basic model PCjr., which didn't come with a disk drive and only 64KB of RAM, and most people bought the enhanced model.

Neither system was intended for a hard disk, and both machines required special drives and interfaces, which were extremely pricey.  Today there is jrIDE for the PCjr. and SmartPortVHD for the //c.  Both are hobbyist projects and tend to be available only at certain times and command relatively high prices.  The jrIDE is connected by the PCjr. sidecar bus while the SmartPort has to go through the much slower floppy interface (its like a big UniDisk drive).

The PCjr. also had a pair of cartridge ports for loading games and instant loading of programs.  There were eight games released and about as many application programs.  Lotus 1-2-3 required both cartridge ports.

Advantage : PCjr.

Memory & CPU

The PCjr. was sold in 64KB and 128KB models, and that was it for memory expansion.  Most people bought the 128KB model, since the 64KB didn't come with a hard drive.  Before the end of its life, it could be expanded to 640KB and 736KB with some work.

The original Apple //c had 128KB and was not intended to be expandable.  Apple released the Memory Expansion Apple //c in 1986 with a memory expansion slot.  The maximum RAM supported was 1MB. Nonetheless, even the pre-Memory Expansion Apple //c can be upgraded to 1MB of RAM, thanks to products from Applied Engineering.  That AE upgrade could also support a Z80 CPU for CP/M compatibility.  Few games ever supported more than 128KB on the //c, but there are many games that require 256KB or more to run on the PCjr.

The PCjr. used an 8088 CPU running at 4.77MHz.  The Apple //c used a 65C02 CPU running at 1.02MHz. The comparison is not quite apples to apples.  The 65C02 can execute many instructions in fewer clock cycles than the comparative 8088 instruction.  The 8088 had many more instructions and registers and could utilize up to 1MB through memory segmentation.  The 8088 uses 16-bit registers or can split them into 8-bit registers, only the external data bus is 8-bit.  The 65C02 only has 8-bit registers, but its access to the first 256 bytes of RAM is almost as fast as access to registers.  The 65C02 could only address 64KB of RAM and Apple //c implemented a complex bankswitching scheme inherited from its predecessors.  A complex game like Microsoft Flight Simulator would show marked improvements on the 8088.

The PCjr. could be upgraded to an NEC V20 for a modest speed boost, and a board could allow the CPU to be run at a 7.3MHz clock rate.  The Apple //c could have its CPU replaced with a 4MHz or 8MHz Zip Chip, turning it into something very much like an Apple //c+

Advantage : PCjr. (stock)

Output

The Apple //c supported all the graphics modes of the 128KB Apple IIe with a revision B motherboard.  This includes 40 column by 24 line text, 80 column by 24 line text, 40x48 low-resolution graphics, 280x192 high resolution graphics and 560x192 double high resolution graphics.  The low and high resolution graphics modes could also support four lines of text.  All Apple IIs, except for the IIgs, produce color by NTSC color composite artifacts.  For text they look best on small monochrome monitors.

There was a DA-15 pin external video connector on the //c, this was used mainly for the LCD attachment.

The IBM PCjr. supported the graphics modes of the IBM CGA card and more.  The PCjr. was only BIOS-level compatible with CGA, unlike the Apple //c, which was hardware compatible with the graphic modes of the earlier machines.  The PCjr. supported 40 column by 25 line text, 80 column by 25 line text, 320x200 4 color graphics, 640x200 2 color graphics, 160x200 16 color graphics, 320x200 4 color graphics and 640x200 4 color graphics.  The PCjr. supported RGBI monitors for sharp images and composite video for color composite artifact color.  It also had a port for an RF modulator.

The Apple //c had a built in speaker, but it was still the same software driven 1-bit device inside all Apple IIs.  There was a volume and headphone jack.  The Apple //c did not have standard expansion slots, so it could not support sound and music boards like the Mockingboard in the ordinary game-compatible way.  The Mockingboard D was made for the //c, but it used the serial port, not the internal bus.

The PCjr. could act like the PC speaker with its timer driven sound, but also had a 3-voice Texas Instruments sound chip.  This chip could produce square waves or noise, but did not use the internal piezo tweeter.  There also was a Speech Attachment available to record and playback digitized sounds and speech.  There was something similar for the Apple //c, the Echo IIC.

Advantage : PCjr.

Communications

The PCjr. had one serial port built in and also could support an internal modem.  The Apple //c had two serial ports.  One was intended for a modem, the other for a serial printer.

The PCjr.'s built-in serial port was capable of 4,800 baud and the official modem was a 300 baud model.  There was a third-party modem built for the slot that supported 1200 baud.  The Apple //c's Super Serial Card-derived serial ports could support a 19,200 baud rate.

The PCjr. had an add-on parallel port that was very a common purchase.  Parallel printers are much faster than serial printers and nowadays are more common.  Moreover, there are PC compatible Parallel Port Ethernet adapters that can enable very fast (comparatively speaking) transfers to the PCjr.

Advantage : PCjr.

Software

The Apple //c was designed to be as compatible with software as possible, as it is essentially a condensed version of the Apple IIe.  Virtually all Apple II disk software is compatible with it.  Very minor incompatibilities exist due to the updated keyboard, the 65C02 not supporting the illegal opcodes of the 6502, DOS 3.2 disks and untransfered cassette programs.  The PCjr. could not make the same boast, as its IBM PC compatibility was hit or miss.  Its issues with PC compatibility are legion and well known.

Advantage and Conclusion : While the PCjr. beat the Apple //c hands-down in almost every comparison, the Apple //c just has a far more expansive library than the PCjr.  That library, which came on 5.25" floppies, is far better preserved and accessible than the software released for the IBM PC and PCjr. of the 1980s.

The Saga of 16 Colors

IBM's original color graphics solution for CGA could display 16 colors.  However, it could not display them all at the same time, except in the text modes.  Otherwise it could display graphics (all points addressable) in limited 320x200 4 color and 640x200 2 color modes. Certain games like Round 42 use the 80 column text mode, tweaked to display an effective 160x100 graphics resolution.  On a real CGA, the 80-column mode would show CGA snow or the graphics would be very slow.

The 1983 PCjr. was IBM's first consumer device that could display all 16 colors on screen at the same time in graphics modes.  Despite the system being much more difficult to upgrade and slower than an IBM PC when equipped with 128KB or less of RAM, its 320x200 16 color and even its 160x200 16 color graphics were far superior to CGA.

The 1984 EGA was IBM's third graphics adapter to see widespread support in games, although the high price of EGA kept it out of reach for most consumers for approximately two years.  It too supported a 320x200 16 color mode and could display 160x200 16 color graphics easily through pixel doubling.

In late 1984, Tandy used a tweaked and modified version of the PCjr.'s graphics adapter in its 1000 series.  The Tandy 1000 supported the same graphics modes as the PCjr.  Games were much more likely to support PCjr. and then Tandy graphics over than EGA in 1985 and 1986.  Even so, there were quite a few budget games and lazy ports even in 1987 and 1988 that supported CGA only, especially in Europe where PCs were expensive and the PCjr and Tandy did not have much of a retail presence (if any).  The Amstrad PC-1512 was one of the best selling PC compatibles of the time, and it supported little beyond basic CGA.  The only advantage it had over regular CGA was a 640x200x16 mode that only a very few games supported.

Games generally would indicate on the box if they supported the PCjr. or the Tandy 1000 series or EGA.  Assuming a game supported all three, like Space Quest III : The Pirates of Pestulon, you could connect the PC with EGA, PCjr. or Tandy 1000 to the same monitor and see identical or nearly identical (Maniac Mansion) graphics.  All these monitors used a digital TTL signal to which was sent a 4-bit RGBI signal.  Thus they could display only 16 colors, and by 1983 IBM had standardized those colors with its 5153 Color Graphics Display.  Outside the digital input, the 5153 was little different than the other RGB monitors non-IBM PCs used, as it used a 15.75KHz horizontal line scan rate and 60Hz frame rate.  TVs also used this scan rate.

EGA could also support 16 colors from a palette of 64 colors, but only using its 350-line modes.  The maximum resolution supported, 640x350 in 16/64 colors, required 128KB of RAM, which was more than the stock IBM EGA card had (64KB).  Relatively few games used this mode, SimCity being the most famous example.  It also required a 5154 Enhanced Color Display or similar monitor, so it was not widely used for games.  The 5154 supported a higher 21.8KHz horizontal line scan rate and 6-bit RrGgBb digital signalling.  The 5154 was backwards compatible with the 5153, with changes on the polarity of the pins telling the monitor whether it would display 200 line or 350 line modes.

EGA also supported a 640x200 16 color graphics mode that saw some use, typically in ports of Japanese PC games like Thexder, Zeliard and Romance of the Three Kingdoms.  Later Tandy systems have an updated graphics adapter that added support for 640x200 16 color graphics, but the mode was very seldom used for games and all games that support it also support EGA.  Additionally, the very popular in Europe Amstrad PC-1512 also supported a similar 640x200 16 color graphics, but only a few games used it.  The Hercules Graphics InColor Card supported a 720x350 16 color graphics mode on an EGA monitor, only a few games used it.

16 color graphics were typically the best quality graphics PC games supported in the 1980s.  256-color VGA graphics did not really become a must-have feature for games until 1990.  Even though EGA was eclipsed by the MCGA and VGA adapters, 16-color games advertised support for these adapters but only displayed their graphics in 16-colors.  However, a few games took advantage of the MCGA and VGA's comparatively vast (256K) palette to display other colors than the canonical 16 colors of CGA.  Moebius : The Orb of Celestial Harmony is a good example.  Thexder is another.

VGA monitors (including MCGA), have a horizontal scan rate double that of a CGA monitor.  To compensate, IBM had these adapters draw each of the 200 scanlines twice.  This gives 320x200 graphics, regardless of color depth, a noticeable "double scanned" look on VGA, with a scanline bisecting each pixel on the line horizontally, regardless of color depth.

16 color graphics typically looked identical whether displayed on a Tandy 1000, an EGA or VGA card or an MCGA card.  EGA was almost always implemented as an expansion card, and VGA could be found integrated into IBM PS/2 systems or cloned on an ISA card.  MCGA never came on a card, like the Tandy 1000 Graphics Adapters and the PCjr. Graphics Adapter.

EGA has the great advantage of being available for any system with an ISA slot.  MCGA and VGA have an even greater advantage by having an output compatible with most modern monitors.  Early Tandy 1000s and the PCjr. also are modern monitor friendly though their composite video output.  While the 16 color output looks good with 160x200 graphics, it looks poor with 320x200 graphics.

VGA is a superset of EGA, and at the 16 color level the cards usually work so similarly that games use the same or almost the same graphics driver.  However, EGA and MCGA function very differently at the hardware level, and a game must support both to provide 16 colors.  MCGA is mostly CGA compatible, and there were games or versions of games that supported only 4 colors with MCGA.  MCGA does not have a true 320x200 16 color mode, so it uses a 320x200 256 color mode, which is slower than EGA.

While Tandy graphics and the PCjr. work very similarly,  there are just enough differences with the adapters and the systems that a game that works on a PCjr. in 16 colors will not work on a Tandy, and vice versa, unless the game was programmed for both or hacked for one or the other.  Tandy graphics work very differently from EGA, so games supporting EGA graphics only tend not to work on a Tandy.  This includes virtually every EGA shareware game of the early 90s (Commander Keen, Duke Nukem, Dangerous Dave).  The Tandy systems, starting with the SX, can be upgraded with an EGA or VGA card, but the software that allows you to switch back to Tandy graphics only works with VGA.

While Tandy graphics (which use a 16-bit data path) are generally faster than EGA graphics (generally put on an 8-bit card) at similar CPU speeds, systems with Tandy graphics max out at a 10MHz 286, while EGA graphics can accompany systems with much faster CPUs.  The IBM systems are stuck with the 8088 PCjr. and the 8086 PS/2 MCGA  Models 25 and 30