Thursday, April 19, 2012

PC Hardware Redundancies

I see little point for people who obtain hardware simply to have it, i.e. pure collectors.  I do not consider most vintage hardware to have any artistic value, as if people are going to go "ooh" and "ahh" over that super-duper rare IBM computer you have in a display case.  It may start a short conversation, except among the like-minded, but otherwise in my opinion it simply takes up space.  In the PC world, most computers looked as at home on a factory floor as in an office.  Apple had some interesting designs around the time of the Mac II and the Apple IIc, and those trapezoidal function keys of the Atari ST and 130XE are truly unique.

I have held that function should hold over form.  My best example is when more advanced hardware totally eclipses less advanced hardware.  For example, why use an Adlib when a Sound Blaster does everything and more?  In most cases, unless you cannot find a Sound Blaster, there is none.  However, there are a few situations where you could find use for one :

1.  A strictly 80's PC with Adlib support, because the Sound Blaster was not available until 1990.

2.  Hardware conflicts with early Sound Blaster cards.  Sound Blaster cards, until the Pro, only supported digitized sound input and output using DMA1.  I am sure some other 8-bit expansion cards required DMA1 to function, SCSI or NIC cards for instance.  I know that the Tandy Sound DAC in the TL/SL/RL requires DMA1 and the Sound Blaster is utterly incompatible with it.  They hate each other.

3.  A mini PC where there is a really tight squeeze for a card.  The IBM PC/XT and XT/286 only supports short cards in two slots, and some Unisys compact desktops will only support short cards.  The IBM PC Portable can only support two long cards due to its design.  Most Sound Blasters extend beyond the edge of a 16-bit connector.

Even so, except for these specialized uses, there is no need for a true Adlib card.  The Sound Blaster is 100% compatible with Adlib software.  The same cannot be said for a Game Blaster and a Sound Blaster 1.0 or an upgraded Sound Blaster 1.5 or 2.0, because the Game Blaster software and some games will fail if they detect something other than a true Game Blaster.  You also have the same issues as 1-3 above.

On the video card front, EGA is generally not a 100% compatible substitute for CGA, but many non-IBM EGA cards do support Hercules graphics with a monochrome TTL monitor.  EGA is virtually 100% compatible with VGA cards, there is only a few titles that tweak the card in some way that most VGA cards will fail.  So unless you really want to use a 200 or 350 line digital RGB monitor, most people use VGA even for EGA games.

Since I mentioned Hercules graphics, why would anyone want to use that when they could use a color graphics card instead?  Well, beyond the "see how it looked" people, Hercules graphics can be a nice addition to a system.  MDA or Hercules graphics can happily co-exist with CGA or Tandy graphics.  You can setup a dual monitor display, but you cannot use both at the same time.  Typically, the MDA/Hercules would display everything using a text mode, and the color graphics card would be used for games and graphics programs.  It actually would be better if you hated CGA snow or the very slow screen updates in 80-column text modes that programs used to avoid it.  On the other hand, the long persistence phosphors of a mono TTL monitor is very different than what people are used to these days.

Unfortunately, nothing can really take the place of a Roland MPU-401 Midi Interface.  There are at least 45 major DOS games that will refuse to work correctly with a UART mode only compatible interface as found on the Sound Blaster 16, the Gravis Ultrasounds, Windows Sound System and Pro Audio Spectrums and Adlib Golds.  Given the midi hanging note bug that most of the Sound Blaster 16 and all the AWE32 and 32s express to some degree, having another card handle the midi interface chores is a good idea.

The Gravis Ultrasound.does not natively support the FM synthesis of the Adlib OPL2 or OPL3 and other sound cards also support digitized sound effects, so why bother using it?  If you are really into the DOS demo scene, that is one reason.  I do not really care about demos in general, I play games.  I have not encountered any game that exclusively supports the Ultrasound without supporting Sound Blaster.  The main issues are performance and sound quality.

Take Epic Pinball, which has great music.  This is one of those games that is a killer app for the card.  It supports the Ultrasound natively, none of this MEGA-EM or S-BOS emulation nonsense.  It supports 16-bit digital playback through the Ultrasound on a 386.  To get close to the same level of quality on a Sound Blaster 16, you need a Pentium for smooth gameplay.  Pinball Dreams, Fantasies and Illusions, Star Control II, there are other great games for the Ultrasound.  Even DOOM and DOOM II can use it for multiple audio streams.

Speaking of the Sound Blaster, should you choose the Pro or the 16/AWE32/AWE64?  If you have a 386 system, choose the Pro, since most games that run well on that tend to be slightly older.  If you have a Pentium, choose the 16-bit card, since that will provide the better sound quality for later games.  If you have a 486, you may wish to consider using both to get good compatibility at both ends of the spectrum.

A Sound Blaster Pro 1.0 is fully backwards compatible with the Sound Blaster 1.0 or 1.5.  The Sound Blaster 2.0 actually came out after the Pro 1.0, but is in between the two products in terms of functionality.  Actually, the Pro cannot support Game Blaster chips, so in a way it is not quite compatible with a 1.0.  This is unimportant for gaming purposes, since you can always put a Game Blaster card inside a system as well (if you can find one).  There will be I/O issues, however, at the cards' default 220 address.   Some games simply couldn't understand that some people may have to use one of these cards at a setting other than the default.

Two FM devices in a system is a recipe for trouble.  It is not a big concern if a game is merely writing to the chips, since you can always find a way to mute the unwanted output.  It becomes a concern if a game is trying to read the chips, since the values read may not be the same.  Usually, the status ports get read at the Adlib port 388H.  While only the status register can be read on an OPL2 or OPL3 chip, games use it to detect and calibrate their delays to write to an OPL2 chip.

PnP capable Sound Blaster cards have the ability to turn off their Adlib ports.  This does not entirely disable the FM of the Sound Blaster, since it can still be read at 2x0 & 2x2 (Pro or better) or 2x8.  However, this will avoid conflicts with programs that read (and write) to Adlib ports.  Moreover, games supporting the Sound Blaster 16 or better typically will allow alternate I/O, IRQ and DMA settings either through their setup programs or through the BLASTER variable.

The Gravis Ultrasound ACE is the only card in the Ultrasound lineup which can do the same thing, and it does it by a jumper.  My card is a 1.0 model, which unfortunately had a reversed stereo jack.  This is fixed in the 1.1 card, or through reversing cables.

Since this is a series of random observations, let me return to the Tandy.  In the hierarchy of sound autodetection, it goes PC Speaker, Tandy/PCjr. Sound, Adlib.  Items like the Game Blaster tend to hover around the Tandy category, and Roland MT-32 always gets manually selected.  If you have a Tandy 1000, I hope you are not nostalgic for PC Speaker sound because many games will force Tandy sound.  But Tandy graphics sometimes requires use of Tandy sound, even if there is an Adlib in the system.

In a Tandy 1000 *X or later, you can put an EGA card in the machine and games using the EGA mode.  Except for those games that use 350-line EGA graphics, the games look identical.  Many earlier games, however, will insist on using Tandy graphics.  Fortunately there is a program which allows you to switch between a graphics card and the built-in Tandy graphics.  Do can also do the same for VGA so long as you can find a card that works in an 8-bit slot and fits inside the Tandy.  Later games like Commander Keen require EGA due to their smooth scrolling effects, so they will only work on a Tandy 1000 RLX or one with an upgrade card.

1 comment:

idspispopd said...

Regarding "Speaking of the Sound Blaster, should you choose the Pro or the 16/AWE32/AWE64?":
The stereo mode of the SB16 is not programmed the same way as that of the Pro. That means if you have a game that supports the Pro but does not explicitly support the SB16 you will lose stereo sound.