Tuesday, April 26, 2022

List of PCjr. and Tandy Exclusive Enhanced Games

The IBM PC computing platform supported gaming from the beginning, but at first its graphical and sound capabilities were not that much more advanced than an Apple II's. Other inexpensive home computers of the day (Atari 800, Commodore 64, TI-99/4A) could run rings around the IBM PC in the video and audio departments. IBM sought to improve its PC line's graphics and sound in an affordable system which became the PCjr., but that was a flop.  Tandy cloned the graphics and sound of the PCjr. and put it into a much more PC-compatible system, the Tandy 1000.  Between the two, the exclusive PCjr./Tandy graphics and sound hardware received wide support from game developers in the mid and late 1980s.  In this article, I will attempt to give a definitive list of games which have "better" graphica or sound on a PCjr. or Tandy 1000 due to this support or have unique video and audio support even if the game can utilize EGA, VGA, Adlib, Game Blaster or Sound Blaster or MT-32.
The Tandy/PCjr. Enhancements - A Short History

The IBM PC's only video display option with support for pixel graphics and color when it was released was the Color/Graphics Monitor Adapter (CGA).  CGA could display 320x200 and 640x200 pixel resolutions, but the 320 pixel mode only allowed the programmer to use 4 colors out of 16 available (3 predefined palette colors with six choices available) and the 640 pixel mode only allowed for 1 color to be chosen from the 16 (plus black).  Sound on the PC was limited to the simple single channel square wave tone generator with no volume control output to the PC speaker.

The IBM PCjr. and the early Tandy 1000s were more (Tandy) or less (PCjr.) PC-compatible, but they offered improved graphics and sound capabilities over the CGA and PC Speaker. These systems had upgraded graphics hardware which could support 160x200 or 320x200 with all 16 colors being able to be displayed and 640x200 with 4 colors being freely selectable. Four voice square wave audio with independent volume and frequency control plus a noise channel was provided by the TI SN 96496 programmable sound generator or the compatible NCR 8496.

Tandy implemented upgrades to its graphics and sound hardware in the Tandy 1000 TL, Tandy 1000 SL and later machines.  The graphics hardware adds a 640x200 graphics resolution with 16 colors but these systems do not output composite video.  The updated sound chip added digitized sound output without significantly tying up the system.  

The downside to using PCjr and Tandy graphics and sound modes is that only the PCjr. and the Tandy 1000 models (until the RLX and RSX) supported them.  The enhanced graphics and sound capabilities  were built-into the mainboards of these machines, and due to their level of integration with the system they would be difficult to clone in an expansion card and retain compatibility with Tandy or PCjr. software.  You had to own one of these systems to use these graphics or sound capabilities, otherwise you were out of luck.  Eventually EGA cards became affordable and supported and could display anything the SL and TL Tandy graphics adapter could display (except composite video).  Adlib and Sound Blaster cards, which plug into ISA expansion slots, found significant support, ending the monopoly of the PCjr. and Tandy 1000s on multi-voice music and digitized audio.  While it did not have the same level of support as those cards or the Tandy/PCjr. sound chip, the Game Blaster brought multi-channel (12) stereo PSG audio to almost 100 games for PCs with an ISA slot.  

Part 1 - Self-Booting Games, a.k.a. "PC Booters"

Software for the IBM PC and compatibles came on floppy disk, and at first programs would be run by putting them into the disk drive, turning on the machine and letting the software boot itself.  While DOS was available for the IBM PC platform from day one, often DOS was not needed to run games which booted via their own routines and sometimes even formatted data disks using simple commands built-into the program.  Some programs relied on DOS to format data disks or make backup copies, but by and large for the first five years of the PC-compatibles' history, programs more often than not came on self-booting disks.  Some PC booters can have their directory contents read by DOS, but they cannot be run from a DOS prompt.


In the table, P/G means PCjr. Enhanced Graphics, T/G means Tandy Enhanced Graphics, P/S means PCjr. Enhanced Sound and T/S means Tandy Enhanced Sound

Some games were released before the Tandy 1000 was available and only support the PCjr. They use software routines to determine whether to offer PC or PCjr. features by detecting whether they are being run on a PCjr.  Below the Root and Bruce Lee are examples of this.  A Tandy 1000 presents itself as a PC, not a PCjr. by the most common detection method which looks at a specific memory byte in the ROM BIOS.  Other games run on a Tandy 1000 but not on a PCjr. because they require 256KiB or more of RAM or only use their advanced graphics and sound if they detect a Tandy 1000.  Defender of the Crown, Marble Madness and Sid Meier's Pirates! are games which do this.

Any color graphics mode can show similar directly-generated colors from a CGA, Tandy or PCjr. on a color composite monitor.  Four games on this list (plus one on the next list) have specific support for IBM PCjr. Color Composite graphics using artifact colors.  In this list, those games with that note use artifact colors produced by the PCjr., which are different than those produced by the IBM PC CGA cards and the Tandy 1000s which have support for composite video.  For these games, some effort was put into making the composite artifact colors appropriate on the PCjr. by using different graphic patterns which permit artifact colors to appear.  Most of these games also have appropriate composite colors for CGA, but some games may require different versions of the software to show proper colors on a CGA card.  

Some of the PCjr.-exclusive games are extremely rare and were only discovered fairly recently.  Styx, Wizard and the Princess and Crossfire's PCjr. disk release were all almost unknown until a few years ago.  Some games have not been found (standalone Boulder Dash from First Star Software) or have broken PCjr. features in the available version (Oil's Well).  The standalone versions of Boulder Dash I and II released by Prism Leisure Corporation were released in U.K. which did not get the PCjr., so those executables were broken by the copy protection used which is incompatible with the PCjr.  Some IBM PCjr. games will work on a Tandy 1000, although some will require the Tandy 1000 to behave like an IBM PCjr., namely by limiting the memory to 128KiB.  Even then they may run too fast or have keyboard issues.  

Part Two - DOS Games

During the mid-1980s, several changes were occurring in the PC landscape.  The first was the emergence of the fixed disk drive, a.k.a. the hard drive.  First introduced to the PC compatible world in 1983 with the IBM PC/XT, the hard drive was an enormously expensive peripheral in the first few years and programs were slow to adopt to being installed on hard drives.  Hard drives could run programs much faster than floppy drives but required a version of DOS that could support their operation.  By the late 1980s the price of hard drives had fallen to a point where it was financially affordable to install one in a PC clone like the Tandy 1000.  Programs had become larger as well and hard drives made floppy disk swapping a thing of the past.


In the list, an "E" means the game also supports EGA, "U" means that the Tandy/PCjr. graphics are inferior but different from EGA graphics, "A" means the game supports Adlib and other sound cards, "Y+" means that the game has support for Tandy DAC but not Sound Blaster.  

Except for games released by Sierra Online, DOS games tend not to work on an unmodified PCjr. and some may require hacking an executable to get them working in a PCjr. DOS games may run slowly on the 8088 CPUs that the PCjr. and early Tandy 1000s were supplied with.  The fastest computer that supported Tandy graphics, and Tandy sound at its original I/O port (C0h), was the Tandy 1000 TL/3, which used a 10MHz 80286 CPU.  The Tandy 1000 RLX supported Tandy sound at I/O ports C0h and 1E0h, but came with VGA graphics built in.  The last Tandy 1000, the Tandy 1000 RSX, and even some non-Tandy 1000s supported the Tandy PSG and DAC, but only at the reassigned I/O port (1E0h) due to supporting a 2nd DMA controller. Games did not support Tandy sound in these machines unless they knew about the new I/O port, and few did.

Two games (Blue Angels, Indianapolis 500) on this list support Tandy composite color graphics.  While these games may look objectively better with other graphics modes, games that optimize graphics to display with appropriate colors on a Tandy 1000 are very unusual.  While the Tandy may not offer ideal graphics in games with VGA support, it can offer unique graphics at times.  Sargon V supports TGA2 and EGA graphics at 640x200 in 16 colors but the game uses different color assignments for each adapter.  

Five games on this list (plus one from the previous) support digitized sound with the PSG without needing the DAC.  This technique was done in a similar manner in which the PC Speaker was driven to produce digital samples, but the PSG often did a better job. Some games also manage this via Adlib and similar means, but the feature is significantly unique that it should be noted when a PSG-supporting game uses it.  

Some games did not support TGA in their first release (and some did not support EGA) or required a special Tandy version to show 16-color graphics and/or PSG or DAC sound with a Tandy.  These versions tend to be very rare, but in all cases except for Gauntlet II's DAC sounds, should be findable on various Archives on the Internet.

Not all DOS games are installable to a hard drive, and many that were required a "key disk" with copy protection features to be in a disk drive when the game ran.  Ultima II: Revenge of the Enchantress requires DOS to run.  You can either boot DOS, switch disks and then boot the game, or you can copy the bootable portion of DOS over to Ultima II's Program Master disk, which would make the game become self-booting.  No version of Ultima II which came on floppy disks is installable to a hard drive.  

While hundreds of DOS games had support for PSG sound, not all of them have especially memorable music.  PSG-style music was not always given priority, often done by USA-based music programmers with no affinity for PSG-style music or often left to the mercies of a generic middleware sound driver.  While any list of games with "good" Tandy music that support sound cards is inherently subjective, let me mention a few DOS games with outstanding Tandy music that all supported Adlib and some supported MT-32: Zeliard, Lemmings 2, Utopia  and Planet X3.

9 comments:

  1. I've ported Commander Keen 4 to the Tandy 1000, including the music: https://www.youtube.com/watch?v=EluZ31ObI1s

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  2. Nice list and explanation!

    I wanted to add a few that are missing; apologies if any were already listed and I missed it, but the following also have some variety of unique Tandy/PCjr support.

    Frogger II: ThreeeDeep!
    — Supports PCjr composite graphics

    Lode Runner
    — Supports Tandy and PCjr composite graphics; not a huge difference, but different dithering patterns for each. Varies by release, with the Tandy 1000 branded version supporting the most options.

    Wilderness: A Survival Adventure
    — This one is debatable, but to me the graphics look like they are optimized for PCjr composite. You can take a look at my Wilderness screenshots and decide if you agree: https://www.pixelatedarcade.com/games/wilderness-a-survival-adventure/screenshots

    Wizard of Id’s WizType
    — Supports PCjr composite graphics.

    Ninja
    — Supports Tandy 160x200, no EGA

    Dungeon Quest
    — Tandy/PCjr graphics exclusive, requires BASIC supporting Tandy/PCjr graphics modes. MobyGames screenshots incorrectly use a version with Screen statements switched to CGA compatible graphics modes, this 1) changes title cards to 320x200 instead of 160x200, and 2) palette commands work different making hidden items visible. I believe this is what it should look like: https://www.pixelatedarcade.com/games/dungeon-quest/screenshots

    Impossible Mission 2
    — Uses Tandy 160x200, different from EGA version

    Pitstop II
    — Supports Tandy 160x200

    Revenge of Defender
    — Supports Tandy 160x200, different from EGA version

    Ernie’s Magic Shapes
    — Original CBS release supports PCjr 160x200 graphics only, Hi-Tech Expressions re-release is CGA only

    Big Bird’s Special Delivery
    — Original CBS release supports PCjr 160x200 graphics only, Hi-Tech Expressions re-release is CGA only

    Timebound
    — Supports PCjr graphics only

    Charlie Brown’s ABC’s
    — Supports PCjr graphics only

    Peanuts Picture Puzzlers
    — Supports PCjr graphics only

    ReplyDelete
    Replies
    1. Thanks for these additions, they have been added to the list. I had debated Lode Runner and Wilderness, completely forgot about Frogger 2, Wizard of Id and Pitstop II, but the rest were unknown to me.

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  3. Does A pcjr version of montezumas revenge exist? I saw it in Jon Hancocks YouTube channel but couldn’t find a disk image online.

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    Replies
    1. The PC version can detect a PCjr. and change its graphics to use the enhanced number of colors a PCjr. can display over a PC with CGA.

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  4. Shanghai supports Tandy color (I don't remember if it has Tandy sound, though). And despite the Tandy-mode executables using "jr" in the filenames, there's no PCjr graphics support.

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    Replies
    1. No Tandy sound, but it has Tandy video, so it is added.

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  5. Thanks for the lists. Off the top of my head, Blockout and Zeliard use higher resolution modes compared to Tandy, probably quite some more among 640x350 and 640x200 titles.

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  6. Rendezvous with Rama also supports Tandy 3-voice sound (which, by the way, you described as 4-voice, which is incorrect).

    ReplyDelete