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!

Turbo Duo - Issues and Solutions

The Japanese PC Engine console was released as the TurboGrafx-16 in the US in 1989.  Conceived as a competitor to the NES and the Sega Genesis, it flourished in Japan, floundered in the US and barely had a presence in Europe.  However, it has many great arcade ports, fun platformers and lots of Shoot-em-ups.

Using HuCards

The TurboGrafx-16 can be a very expensive system to collect games for.  Japanese systems use HuCards for the games on ROM.  HuCards are slightly thicker than a credit card and have exposed contacts which get inserted into the card slot on a Turbo system.  Some US material called them TurboChips.  Japanese and US HuCard games are functionally identical but not pin compatible, requiring a region mod or a converter PCB to use cards for the other system.

However, it  is surprisingly easy to play games on any NEC system these days if you don't want to engage in the pricey journey to collect HuCards.  A Turbo Everdrive from Krikzz will play any official, licensed game (with one exception, see below). The Everdrive has a switch to select the console's region and an SD slot to load ROMs. The current card is flash based and loading a new game requires rewriting the old game.  The currently written game can be selected instantly by pressing the select button.  Writing a large 1MB game like Bonk's Big Adventure only takes about 11 seconds. There will be a newer, RAM based version released in the near future that will make loading faster and end worries about reaching the write limit of the flash media. However, the media should be rated for at least 10,000 write cycles, so if you flashed a new game every day it would take you at least 27 years to exhaust the memory.

The Everdrive can also be used as a CD System Card 2.0 replacement by loading the ROM.  It does not have the extra RAM needed for Super CD System 3.0 Card support or an Arcade Card.  It will work with the game Populous only in the Turbo/PC Engine Duo console line because that game came with extra RAM that is duplicated in the CD systems.  However, you can include the Super CD System ROMs so you can play CD games with an Everdrive installed in your Turbo Duo.  You can also load the US ROM in case you forget what the save RAM options are if you have a Japanese system.

One other irksome issue with regions is that the PC Engine uses a different gamepad connector from the TurboGrafx-16.  All Japanese consoles uses a mini-DIN-8 connector while TurboGrafx 16s use a DIN-8 connector. The US Turbo Duo also uses the min-DIN connector.  The controllers and multitaps themselves are otherwise compatible and there are converters available.  Japanese controllers and multitaps are often easier to find than their US equivalents.

A final issue is that the original PC Engine and TurboGrafx-16 were RF only.  The TurboGrafx-16 required a Turbo Booster or the TurboGrafx CD add-on for stereo composite AV output .  The PC Engine usually did the same through the PC Engine CD.  As I mentioned in my RF blog entry, Japanese RF channels are not the same as US RF channels.  NEC later released the Core Grafx and Core Grafx II consoles which replaced RF with stereo AV output.  There is also the PC Engine Shuttle which supports stereo AV but has no expansion port for a CD add-on.

Using CD Backups

The TurboGrafx CD was the first CD-based console add-on.  It came with the CD unit, a Docking station and a CD System Card (2.0).  All three pieces are required to make it work with the TurboGrafx-16, and it makes the system look like a large, black inverted-T.  The system could be upgraded to play Super CD-ROM games with a Super System Card (3.0).  These are hard to come by for the US console.

In 1992, the TurboGrafx-16 and TurboGrafx CD were released in a combined unit called the Turbo Duo. Japan's version is called the PC Engine Duo.  The Turbo Duo plays US HuCard games but uses the controller ports from the Japanese consoles.  It also uses a 5-pin DIN AV output connector which supplies composite video only and stereo audio.  Finally it has a stereo mini-jack for headphone output.  The Japanese version is identical except for the color of the buttons and the support for Japanese HuCards.

NEC later released the white PC Engine Duo-R which removed the headphone jack and the lock switch for the CD cover.  Finally, the PC Engine Duo-RX was slightly cosmetically different from the Duo-R but included a six-button gamepad.  Only a few Japanese games like Street Fighter II - Championship Edition supported the 6-button pad.

Any of the Duo consoles are expensive ($250-$350) to acquire, but playing backups of the CD-ROM games are cheap.  The original Duos will almost certainly need to have the capacitors replaced. The Duo R and RX have a reputation for being more reliable. The lens assembly may also need to be replaced.  However, you are really getting the full NEC console experience with one of these systems and it can play a ton of great games.

In burning CD backups, however, you have a challenge.  Turbo CD games rarely look like standard CD-ROMs.  Except for a very few CDs with only a data track, all CD games are mixed mode games with data and audio tracks.  For these games, the first track is always an audio track intended to warn the user not to play the CD in a CD player.  The second track is always a data track (and the reason for the warning), and for some of the simpler CDs, they only have one data track.  CDs with more complex mastering also have a second data track as the last track on the CD.

There is nothing inherently non-standard about mixed mode CDs.  Many, many MS-DOS CD games used a data track and one or more CD audio tracks.  Most Sega CD, Neo Geo CD, Jaguar CD, 3D0 and some Sega Saturn and Sony Playstation games used mixed mode CDs.  However, for the MS-DOS CDs, Sega CDs and Sony games, their CDs always have just one data track and it is always the first track.  One or more audio tracks follow.  Turbo CDs, even those with only a data track, are not readable in a PC except as an audio CD.

A good backup uses high quality media.  I have read good things about Taiyo Yuden CDs, and I have also used Sony SUPREMAS CD-Rs with some success.  Ideally these CDs should be burnt as slowly as your burner can burn them. However there are several caveats to this.  First, modern CD-Rs were designed to be burnt at 16x speeds or better, as are modern burners.  Second, if you use a really old burner it may not support the ideal settings for burning Turbo CDs.  The ideal setting is to use a CUE sheet (either with a BIN or ISO and WAV) in the Disk at Once mode.  Really old burners may not support Disk at Once or may balk at the nutty mixture of audio and data tracks some of these images have.

Compared to playing with original pressed discs, the CD motor may exhibit more noise and the load times may be longer.  Load times for pressed media are often very quick.  It takes virtually no time for even a 1x CD-ROM unit like the one in a Turbo console to switch and audio track.  Additionally, there is only so much RAM to fill in a Turbo system (8KB CPU RAM + 64KB Video RAM + 64KB ADPCM RAM + 64KB CD-ROM RAM + 192KB Super System Card RAM).  A 1x CD-ROM transfers at 150KB per second, so load times should be fairly reasonable.  When you get to Arcade Card games, which add another 2MB of RAM, things might take longer.

Here is a list of all US released CD games by their type :

Two Data Tracks US CD Games
Buster Bros.
Fighting Street
J. B. Harold Murder Club
Jack Nicklaus Turbo Golf
Last Alert

Two Data Tracks US Super CD Games
Bonk III - Bonk's Big Adventure
Cotton - Fantastic Night Dreams
Dragon Slayer - The Legend of Heroes
Dungeon Explorer II
Dungeon Master - Theron's Quest
Fantasy Star Soldier
Forgotten Worlds
John Madden Duo CD Football
Lords of Thunder
Might and Magic III - Isles of Terra
Prince of Persia
Riot Zone
Shadow of the Beast
Sim Earth - The Living Planet
Super Air Zonk

Interleaved Data and Audio Tracks US CD Games
Cosmic Fantasy II
Magical Dinosaur Tour
Valis III

Two Data Tracks US Super CD Games
3 in 1 DUO Demo CD
4 in 1 Super CD

Single Data Track US CD Games
Final Zone II
It Came from the Desert
Lords of the Rising Sun
Splash Lake
Valis II
Ys Book I & II
Ys III - Wanderers from Ys

Single Data Track US CD/Super CD Hybrid Games
Sherlock Holmes Consulting Detective Volume II
Syd Mead's Terra Forming

Single Data Track US Super CD Games
Beyond Shadowgate
Camp California
Dynastic Hero, The
Exile II - Wicked Phenomenon
Meteor Blaster DX
Shape Shifter (98 Tracks!)

Data Only US CD Games
Addams Family, The
Bikini Girls
Hawiian Island Girls
Local Girls of Hawaii, The
Sherlock Holmes Consulting Detective can inform you of the proper CUE sheets for every CD game, US or Japanese.

Even if you have a Turbo Duo, you should still keep the BIOS images for the Super System Card on your Turbo Everdrive.  You can load the BIOS image into the Turbo Duo to play CD games without having to remove the Everdrive.

Getting into a PC Engine Duo requires using a T10 Torx Security bit, a Turbo Duo requires a 4.5mm gamebit, which is also used with the SNES and N64 consoles and Genesis cartridges.  Inside the CD systems are five potentiometers marked VR101-105.  You can use a small screwdriver to adjust these if the drive is not spinning or CD audio is not playing.

Video Output

Unfortunately, no Turbo console outputs anything better than composite video.  Despite their limited 512-color palette, the Turbo consoles could put out some very colorful images and do not generally look their best with composite.  Fortunately, Hu6260 GPU outputs all the signals needed for RGB and S-Video.  There are many mods, and all require obtaining these signals from the chip itself or the expansion connector.  The PC Engine Duo I have been testing has an RGB mod from a Japanese seller called doujindance.  His mod is passive and very small.  The 5-pin AV DIN is replaced with an 8-pin DIN, with the extra lines being wired to R, G and B.  Sync is taken from the composite video pin.  This mod retains compatibility with existing composite video cables.  Other mods convert RGB to component video.

RGB looks quite superior to composite video, especially in games that use 320 horizontal pixels rather than the more common 256 horizontal pixels.  However, with the RGB amplifier in my system, one can see jailbars in the image that are not present through the composite output.  Jailbars are alternating patterns of light and dark across the screen and they are quite obvious in some games but not in others.  Bonk's Adventure is a game where they are immediately noticeable.

Save Game Backups

HuCards typically used passwords for saving, but a few Japanese supported the Tennoke 2 Backup Unit.  This device plugged into the back of a PC Engine's expansion port.  The Turbo Duo implements 2KB for game memory saving.  Many Turbo CD games only require a fraction of this memory, but some may require most or all of it. Multiple saves can be stored in the system, but there is no real way to transfer saves off the internal memory.  This 2KB SRAM chip is not battery back but instead is kept energized by a large capacitor (I have read the Duo-R has a lot more RAM).  The SRAM will completely drain the capacitor in approximately two weeks if the console is not turned on in that time.  NEC made the Tennokoe Hu-Card to backup saves from the unit.  This device appears to use flash memory, so you don't have to worry about the battery dying.  The current Turbo Everdrive does not support backing up the internal memory, but the next one may).

Wednesday, April 22, 2015

SCUMM Console Ports - Turbo Duo Loom vs. Sega CD Monkey Island

LucasArts was established by computer game programmers, but by 1990 they were becoming increasingly involved into consoles.  Having the Star Wars and Indiana Jones licenses practically demanded home console games using the licenses.  Except for the port of Maniac Mansion for the NES, LucasArts produced or licensed nothing of note until the SNES.

LucasArts was interested in porting its highly acclaimed adventure games series, using the SCUMM engine, to consoles.  Their adventure games were relatively large by cartridge standards, but the new CD-ROM add-ons for the Sega Genesis and Turbo Grafx 16 could easily contain their adventure games and allow for 16-bit CD Audio.  LucasArts commissioned a port of Loom for the Turbo Duo and a port of The Secret of Monkey Island for the Sega CD.


Loom - Turbo Super CD Title Screen
Loom for the Turbo systems was intended to run on a Turbo Duo or its equivalent : a Turbo Grafx 16 with the TurboGrafx CD and a Super System Card.  It will also run on the Japanese equivalents.

The Turbo port is  graphically in between the 16 color floppy and the other (mostly) 256-color CD-ROM versions.  If I had to give a hierarchy of ports based solely on the graphics, it would go something like this :

Loom IBM PC 16-color floppy
  • Atari ST 16-color floppy
  • Amiga 16-color floppy
  • Macintosh 16-color floppy
Loom 256-color FM-Towns CD 
Loom 256-color IBM PC CD
Loom 16/256-color Turbo CD

The Turbo CD and FM-Towns CD have similar CD-Audio tracks, which are used for music.  The first set of FM-Towns arrangements (first nine audio tracks) are used for the Turbo CD music.  Musically, this may be the best version, as the FM-Towns also uses second set of music tracks.  The second set sounds more like a synthesizer than the first set and in my opinion is inferior.  Unfortunately, the FM-Towns version plays the first set, then the second set and keeps repeating the second set.  

Loom Turbo Super CD 16 Color Original Background
What is odd is the graphics used on Turbo Loom.  Both the FM-Towns and the IBM PC have full 256-color graphics above the distaff.  Turbo Loom uses a mixture of backgrounds (including portraits) from the 16 and 256 color IBM PC releases.

Consider the sources of the closeups :

Bobbin Threadbare - 16 Color
Hetchel - 256 Color
Elder Atropos - 256 Color
Hetchel as Cynget - 16 Color
Master Goodmold - 256 Color
Fleece Firmflanks - 16 Color
The Dragon - 16 Color
Rusty Nailbender - 256 Color
Master Stoke - 16 Color
Dragon finds Rusty - 256 Color
Bishop Mandible - 16 Color
Cobb - 256 Color
Rusty as a Ghost - 256 Color
Lady Cygna Threadbare - 16 Color
Chaos - 256 Color

Generally, most of Loom island is taken from the 16-color version, with notable exceptions of the Dock, the Loom Sanctuary and Lady Cygna's gravestone closeup.  Crystalguard is entirely 16-color.  The beach, the Shepherd's forest and meadow are taken from the 256 color version, except for the interior of Fleece's hut. The exterior of the Dragon's volcano and its lair are 256 color, as is the Forge and the plain surrounding it. Bishop Mandible's cathedral and the Outside is 16-color except for the very end of the game.

Loom Turbo CD - 256 Color Original Background
The characters are always 256 color, as are most of the animated objects.  The distaff portion of the screen is 16 color regardless of version (although the FM-Towns version has a distaff that does not use the EGA palette).

Why did LucasArts take roughly 50/50 from each version when the Turbo Duo was capable of almost 256 colors (but only a 512 color palette)?  Storage was not an issue with a CD game.  One theory is that the remaining 256 color graphics were not available in time for the Turbo port, so LucasArts had to make do with whatever 256 color art was available at the time.  I am not satisfied with this theory because the FM Towns 256 color version, done in-house by LucasArts, was ready by April, 1991.  The PC CD version was ready by June of 1992.  The Japanese PC Engine Duo version was released in September of 1992 and the US Turbo Duo version followed in December.  I can see no reason why all the 256 color artwork would not have been available for the Turbo port.

An alternative view is the 256 color graphics that they did not use either did not look very good once the color depth had been reduced or they did not look good on a composite monitor.  No NEC console, whether Japanese or US, supported better than composite video at the time Loom was being ported.  What may have looked good through an RGB monitor on the development hardware may have looked like crap on composite.

In instances where the 16 color graphics are being used, the Turbo through a composite monitor looks scarcely better than a Tandy 1000 outputting the 16 color IBM PC floppy graphics to a composite monitor. I recently made a post extolling the underrated virtues of composite video on the SNES and Genesis, but this game was designed on a PC and looks best through a lossless analog connection.  In other words, it looks best on an RGB modded Turbo Duo.  Unfortunately, no NEC console in the TurboGrafx line, not even the SuperGrafx, has native RGB support.

On the PC and other versions, the main graphics window uses 320x136 pixels. The Turbo uses 338x136, but the cursor is limited to the right-most 320 pixels.  Virtually all this horizontal resolution can amazingly be squeezed into the viewable screen of a CRT.  If a screen is non-scrolling, then there will be a noticeable black border on the left side of the screen.  The same is also true of the leftmost side of a scrolling screen.  Vertically, the game does not appear to use any of the vertical space above the main graphics window, but the cursor will descend to line 240 and perhaps line 242, which is the absolute vertical limit of 240p.

Even though the PC Engine did have a mouse available for it, Loom does not support it.  However, it does have some neat options.  It can change the text speed, it can turn the sound effect and music, or just the music, off, and also has a sound test that allows you to listen to any of the CD audio tracks.  The Overture (from Swan Lake) is not otherwise heard in the game.  It also has an option to limit the animation to improve speed, but Loom is not an animation-heavy game (The Secret of Monkey Island is much more animated), so this option would not often be useful.

The saving system is non-intuitive.  Loom will save a game to the backup RAM of the CD unit.  However, it really only saves a checkpoint, the first being when after you reach the beach leading to the Shepherd's forest and Crystalguard.  So if you save prior to leaving Loom Island, you will load back to the very beginning before you acquire your distaff.  You can lose a lot of progress this way because the save points seem quite spread out.  Button I skips cutscenes, perhaps for this reason.

The Secret of Monkey Island

The Secret of Monkey Island Sega CD
The Secret of Monkey Island for the Sega CD is based on the IBM PC CD-ROM version, reducing the on-screen number of colors from 256 colors to a maximum of 64 colors, similar to the Amiga.  The actual game's hierarchy is less complicated :

The Secret of Monkey Island 16-color floppy
  • Atari ST 16-color floppy
The Secret of Monkey Island 256-color floppy
  • Amiga 32-color floppy
The Secret of Monkey Island 256-color IBM PC CD-ROM
  • FM-Towns 256-color CD-ROM (uses 16-color inventory icons, Japanese and English available)
  • Sega CD 64-color CD-ROM
  • Macintosh 256-color CD-ROM (has graphical filtering option) 
The Sega CD does not use the save RAM inside the CD unit, instead it gives a 4-digit passcode to restore a game.  It is rather amazing that LucasArts could fit all the information needed to restore a game in essentially four bytes.  This passcodes will only restore your game if you have made a substantial achievement like completing one of the three trials.  Your inventory may not be exactly as you had left it, nor may your character be where you left him and the dialogue options may be reset (which is terrible for the sword fighting trial), but you will not get stuck because you don't have an object you need.  You may have to acquire some items again unfortunately.  Button C is used to skip dialogue, and this was probably implemented for this reason.

The Secret of Monkey Island Sega CD SCUMM Bar
Interestingly, this port has support for the Sega Mega Mouse peripheral, making it function much more closely to the computer versions.  This is not mentioned in the US manual or on the US box, but there is a symbol for it on the Japanese box.  The mouse support is present on both the Japanese and US versions of the game.  The game was not released in Europe.

The gameplay itself is not too bad, but it will slow down if there is a lot of animation on the screen.  Scrolling is also jerky when there is a lot of animation on the screen.  When you are selecting dialogue, the cursor disappears, even if you are using a mouse.  The only option of is to change the text speed.  The dialogue options are sometimes redone for this version to decrease the number of dialogue choices that use a second line.

The Secret of Monkey Island Sega CD Portrait
The graphics are dark, especially the backgrounds on Melee Island.  The backgrounds are those used from the Amiga version, 256-colors reduced to 32-colors, but the Sega color palette appears much darker than the Amiga palette.  I guess LucasArts believed that people would simply turn the brightness of their TV up if they felt the screen was too dark.  On the other hand, the character, object and inventory graphics have been converted from the 256 colors of the PC CD version.  The CD audio is more or less identical to the PC CD version and plays the music as it does in the PC CD version.  One positive thing to note is that the Genesis Model 1 and 2 always support RGB output, so the graphics can look pretty nice.

The load times are rather annoying.  There are load times for every time you enter into a new screen, begin dialogue, acquire an item and other characters move on the screen.  Much of this is due to the limited RAM available for the Sega CD.  The average 1992 PC would have had 4-8MB of RAM while the Sega Genesis and CD combined have 832KB.

So, Which is Better?

This is a hard decision, because I cannot honestly recommend either port.  Both have klunky saving and loading, and both have graphical issues.  The Secret of Monkey Island is too dark (but can be improved with RGB), Loom is too inconsistent.  Audio-wise, both are excellent.  There are noticeable slowdowns early in SoMI and lots of CD load times.  It is the load times that kill the Sega CD port.  Loom is a much simpler game and was better suited to the 8/16-bit consoles of the 4th Generation.  

Tuesday, April 7, 2015

IBM Character Fonts

IBM used several fonts during the life of the IBM PC line and soon thereafter.  Eventually the font support would be finalized into the standard VGA font, but there was quite an evolution to get there.

The first font set is  found in the IBM PC BIOS, starting at address FFA6E.  In PC BIOSes, whether from IBM or from another publisher like Phoenix, Award or AMI, you will always find a font beginning at this address.  This address contains the dot patterns, or glyphs, for the first, basic 128 ASCII characters. The font is always in an 8x8 pattern and essentially acts like a fallback for programs using graphics modes. You could only find the glyphs for the second, extended 128 ASCII characters on the display adapters themselves.

Note the extra pixel in the diamond character in the first row.  This is unique to the first IBM PC Model 5150 BIOS revision.  That pixel will be gone in the PC BIOS dated 10-19-81 and every other BIOS thereafter.  Note that the second 128 characters do not exist in the PC BIOS's ROM.

MDA & Hercules

MDA and Hercules-brand graphics cards share the same glyph patterns.  Their text mode uses a 9x14 text cell and you were strictly limited to the 256 characters contained in the Character Generator ROM on the display adapter.  If you wanted to use non-IBM characters with a basic Hercules Graphics Card, you would use the graphics mode.  A Hercules Graphics Card Plus or Hercules InColor Card can redefine the characters in text mode.  Here is what the demo screen looks like on an MDA or Hercules :

Interestingly, the MDA's Character Generator is an 8KB ROM chip, even though its font only takes 4KB.  The other 4KB contain the two CGA fonts described in the next section.  Apparently it was easier to use one ROM for both cards.  The IBM Part number on the chip is 6359300 or 5788005 and the ROM is a 9264 type, so it cannot be dumped or replaced by an EPROM without a pin adapter.  The Character Generator ROMs cannot be read by the system, so the glyph patterns are obtained via a ROM dump.

CGA & PCjr.

CGA text modes always use an 8x8 text cell and typically uses a thick, double-dot font.  A true IBM CGA card also has a thin, single-dot font.  This can be selected by bridging two solder pads just below the MC6845, but IBM did not provide a pair of pins to make this easy for end users.  The thick font was suitable in 40-column mode for TVs, but the thin font shows a lot of color fringing, a.k.a. artifacts.  IBM probably thought that the thin font was not such an important feature that it should be made accessible to end users.  Otherwise, many users would have probably complained that the text was too difficult to read on their TVs.

This is what the standard thick font looks like :

Note that there are four characters with minor differences between the Character Generator ROM font and the BIOS font.  They are listed as "8x8 different between card and BIOS" in the screenshot.

Here is the thin font, which may have been IBM's first attempt at ISO compliance :

The PCjr. fonts should be identical to the CGA fonts, but the thin font is not available.

Tandy 1000

The Tandy 1000 contains a Character Generator ROM that is mostly similar to IBM's CGA double-dot font, but there are some differences :

In the original 1000, the Character ROM is embedded in the Video Gate Array chip.  After the original 1000s, the Tandy integrated the Video Gate Array and MC6845s into a large VLSI chip.  This applies to the EX, SX, HX and TX.  Internal to these chips is a 2K Character Generator ROM.  In the above screenshot, the first 128 characters are correct because they are duplicated in the Tandy BIOS at address FFA6E.  It is very difficult to extract the patterns for the second 128 characters because they are not in an accessible or dumpable ROM.  Here is what the characters truly look like :

By the time of the TL and SL, Tandy was using the Tandy Video II chip and an external 16KB Character ROM with the 8x8 font and a 9x14 font that may or may not be identical to IBM and Hercules.  The Video Controller in the TL and SL and their successors could emulate MDA and Hercules text and graphics.

The Tandy default text mode uses a 8x9 text cell, but usually an 8x8 text cell can be used.  For most characters, the extra row is blank, but for some the ninth pixel row is a repeat of the eighth pixel row.


With the EGA, MCGA and VGA adapters, the Character Generator ROM would no longer be found on a separate ROM chip accessible only to the CRT Controller.  Instead, multiple character sets would be contained in the BIOS Extension ROM (for EGA and VGA) or within the BIOS (for MCGA).  As these adapters supported redefinable character sets in text mode, DOS could upload its own character set for display.

The EGA BIOS supports an 8x8 text font when displayed on 200 line monitors, an 8x14 text font when displayed on 350 line color monitors and a 9x14 text font when displayed on a monochrome 350 line monitor.  The 9x14 characters are identical to the MDA characters, but many are shifted a pixel one direction or another to produce a more pleasing spacing (kerning) than MDA.  The 8x14 characters are mostly identical to the 9x14 characters, but there are differences.  The first 128 8x8 characters are identical to the PC BIOS and the second 128 8x8 characters are identical to the CGA thick text font.  All these fonts are stored, uncompressed, in the EGA 16KB BIOS extension.

This is the EGA and VGA and (for the first 128 characters) the standard PC BIOS 8x8 text font :

Here is the EGA and VGA 8x14 text font :

And the EGA and VGA 9x14 text font :


MCGA includes a 8x8 and an 8x16 text font.  Actually, the MCGA, in addition to the standard 8x16 font, also contains four more 8x16 fonts, none of which ever obtained popularity.  These may have been IBM's attempt to be ISO compliant.

This is the standard 8x16 font for MCGA and VGA :

In addition, PS/2 Model 30s with a revision 0 BIOS contained an earlier version of the 8x16 font.  In this font, the zero character has a slash instead of a dot.


VGA supports the EGA 8x8, 8x14, 9x14 fonts and 8x16 and 9x16 fonts.  These are all found in the VGA BIOS ROM extension, which can be 24KB-32KB.  With 8x14 and 9x14 or 8x16 and 9x16, with EGA and VGA the glyphs are mostly the same and only one set is stored in the ROM unless there is a substitution for a particular glyph.  The BIOS adjusts for the ninth pixel column, for most characters the column will be blank; for others, the ninth column will repeat whatever is in the eighth.

Here is the final, standard 9x16 VGA font :

DOS Code Pages

The PC was originally designed by and intended for English speaking countries.  Support for other languages was a cumbersome exercise in the early days of MDA and CGA.  Eventually, DOS 3.3 introduced Code Pages, which when combined with an EGA or VGA card, allowed the user to set his PC to his country's symbols.  English language users would generally be content with the default DOS code page, 437, or the alternate English code page, 850.  Code Page 850 is more friendly to Western European languages than 437 but loses some of the drawing characters.  DOS's .CPI files would contain character sets for several code pages, each of which had character sets for 8x8, 8x14 and 8x16.  EGA.CPI contains 437, 850, 852, 860, 863, 865.  Here are 437 and 850 :

While the Tandy Video II chip found in the TL and SL does not support software redefinable fonts, it has support for 512 characters instead of just 256.  (EGA can also support 512 characters).  The first 256 are the characters in Code Page 437, the second 256 characters are those of Code Page 850.  However, as Tandy 1000s after the original can be upgraded to EGA or VGA, Tandy MS-DOS 3.3 supports Code Pages in 8x8, 8x9 and 8x14 text cell sizes.

ISO.CPI contains an English-language character sets suitable for ISO-compliant fonts :

Special thanks to NewRisingSun for all his help with this blog entry.