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From: jky@cs.bu.edu (John Yu)
Newsgroups: rec.games.video.misc
Subject: ### TG16/DUO FAQ: 01/17/84 ###
Date: 17 Jan 1995 16:40:46 GMT
Organization: Computer Science Department, Boston University, Boston, MA, USA
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*******************************************************************************
** _____   __   .    __      _  __   _    _   ___                   _____    **
**   |    /  \ /|   /__     /  |  \  |    |  /   \                /    /    **
**   |   |  __  |  /   \   /   |   | |    | |     |               /   /_     **
**   |    \__| _|_ \___/ _/    |__/   \__/   \___/              /__   /     **
**  ___    _      ___                                / /         **
** |__    / \    /   \        Compiled by John Yu               //         **
** |     /___\  |   \ |       Email: jky@csa.bu.edu             /          **
** |    /     \  \___\        Last revised: 01/17/95                     **
*******************************************************************************
** The source of information for the TurboGrafx16 and DUO video game systems **
**             Email any comments/questions to jky@csa.bu.edu                **
*******************************************************************************

ACKNOWLEDGEMENTS: Thanks to Ken Arromdee (arromdee@jyusenkyou.cs.jhu.edu)
            and Steve Pearl (pearl@remus.rutgers.edu) since alot of
            the stuff in this FAQ were borrowed from their own FAQ's
                  based on the same subject matter. :)
            Thanks to Bt Garner and everyone else who have contributed
               to the FAQ :)

Information needed:
-- The TurboExpress and TG-16 information are inconsistent in CPU and Mhz.
   What's the deal? :)
-- Is there now only one magazine left in Japan solely devoted to the PcEngine?
   Which one?
-- Is there an adaptor to play PcEngine HuCards on the LaserActive?

Changes since last posting:
-- Kisado adaptors found.  (See Section 3.C)
-- TG16->Duo Joystick cable pin-out.  (See Section 4.D)
-- BuyRight price list on WWW.  (See Section 7)
-- Game Zero on WWW.  (See Section 8)
-- Michael Mahon's Home Page on WWW.  (See Section 8)
-- Hudson Soft Hucard Release list.  (See Section 8)
-- Save game FAQ.  (See Section 8)
-- Game FAQs ftp site directory change.  (See Section 8)
-- PcEngine Fan Scans ftp site.  (See Section 8)


------------------------------------------------------------------------------

=========================
Contents
=========================

     1  TTI
     2  TG16->Duo Lineage
     3  PcEngine+Compatibility
        A: The Machines
        B: The Games
        C: The Accessories
           -PcEngine->TG16/Duo Adapters
           -PcEngine and TG16/Duo Controllers
     4  Technical/System Specs
        A: Machine Specs
        B: PcEngine/TG16 Hucard pinout
        C: TG16/Duo and 6-button button joystick techs
           D: TG16->Duo joystick converter cable pin-out
        E: Technical Questions Answered by Nimai Malle
     5  Other Frequently Asked Questions
     6  Magazines
     7  Shopper's Guide
     8  Other Sources of Info

=========================
1  TTI
=========================
o What is Turbo Technologies and what happened to NEC?
     NEC had joined forces with Hudson-Soft to form a new company called 
     Turbo Technologies.  TTI hasn't done very well in marketing Duo, and 
        as a result, they are no longer in business.  Turbo Zone Direct has
     risen from the ashes of what was TTI.  TZD is no longer distributing 
     hardware and is concentrating on selling software through mail order.
     TZD has promised to continue to port over Japanese titles, and is also
     selling the back log of NEC & TTI games.  The Duo is available on 
     clearance from retailers at the price of $100 and the TG16 base unit 
     can be found for $20-$40.  New software plans are slow to non-existent
     but there is still alot of US software out there if you're a new user.
     If you're a TG16 oldie like me, the only solution is the still strong 
     Japanese market of PcEngine games.  See Shopper's Guide section for a 
     list of distributors.


=========================
2  TG-16 -> Duo Lineage
=========================

Back way back when, NEC entered the 16-bit generation US video game market
by promoting the TG16,TG16-CD, and later the TurboExpress portable.

TurboGrafx-16:  -This base unit plays only Hucards (thin, credit-card sized
           cartridges)
          Assessories:
          1) TurboTap: adaptor allowing 5 player capabilities
          2) TurboBooster: attaches to TG16 expansion port to allow
                     A/V cable hookup to TV/Stereo
          3) TurboBooster Plus: same as TurboBooster but allows
                          Hucard game saving on those games
                          which support the feature

TurboExpress:  -A portable handheld system equivalent to TG16
          -Plays only Hucards
          Assessories:
          1) TurboVision: TV tuner attachment
          2) TurboLink: Connects two TE's together to allow 2 players*
                     * only works for games which support this feature
          3) Car Adaptor
          4) AC Adaptor

TG16-CD:  -Comes as a CD attachment for TG16 base unit.
          -CD plays audio CD's, CD+G's, and CD-ROM2 games (The "2" in 
           CD-ROM2 supposedly refers to CD operating system version 2)
          Features:
               -Adds A/V output and headphone jack
               -CD can be removed for use as portable
               -On screen display to play audio CD's and CD+G's
               -game save battery feature

          -With the Super System Card (system version 3) upgrade, plays 
           also Super CD** games for the DUO.
           May be still available from TTI/TurboZone for $65 alone
           or $95 along with 3-in-1 CD containing Gate of Thunder,
           Bonk1+2, and bonus Bomberman game (see Shopping section)

After a few years of lack-luster marketing by NEC, NEC joined forces with 
Hudson-Soft in forming TTI to promote the DUO and the Super System Card
for the TG16-CD.

DUO:      -The TG16's successor
          -Super CD system 3 built in
          -Plays audio CD's, CD+G's, CD-ROM2 and Super CD** games as
           well as standard Hucards           
          Features:
               -Faster access time than TG16-CD unit
               -slimmer design than TG16-CD but no LCD on unit
               -A/V output and headphone jack
               -On screen display to play audio CD's and CD+G's
               -game save battery feature


     ** Super CD:   Using a revised BIOS (Operating system) and more 
               memory (64K upgraded to 256K), Super CD games run
               faster because of less access time and have better
               graphics due to the increased memory.
               Only Super CD games take advantage of this extra
               memory.  There are some games which are compatible
               with both System 2 and 3 but will take advantage
               of System 3's extra memory when it is present.

Arcade Card:   -Probably the final expansion for the PcEngine/TG16/Duo
           There are no plans to release it or any of its games in the 
           US.  Using this card, memory is expanded to 2MB.  The more
           memory, the better right? :)
          -There are two versions of the Arcade card depending on
           the type of system you have:
               1) Arcade Card Duo: for Duo based systems
               2) Arcade Card Pro: for non SuperCD based CD systems,
                             it includes both the SuperCD 
                             operating system and the extra 
                             memory on the card
          -If you have a US machine, you have to use a HuCard adaptor
           for it to work on your machine.
          -Most Arcade Card games are Neo-Geo fighting game ports.


=========================
3  PcEngine+Compatibility
=========================

A: The Machines:
----------------
PcEngine Shuttle:  Japanese counterpart of TG16 but without CD expansion
             capabilities.  Plays only Japanese HuCards.

PcEngine/CoreGrafx/Duo:  Japanese counterpart of TG16/Duo. 

Supergrafx:  No US counterpart.  (The Supergrafx is an enhanced PC Engine and
          can play PC Engine games without modification.)  There were only
          five games produced exclusively for this machine to take 
          advantage of its extra muscle power.

PcEngine GT:  Japanese counterpart of the TurboExpress, and runs PcEngine
           HuCards.  To play PcEngine HuCards on TurboExpress, use
           the same PcEngine->TG16 adaptor.

B: The Games:
-------------
HuCards:  1) PCEngine on TG16/Duo:
             HuCard games aren't compatible, but you can buy adapters 
             for $20-30 through many mail order places.
          2) TG16/Duo on PCEngine:
             There is a hardware difference between the two machines 
             which HuCards can read.  Most TG-16 HuCards check it,
             and won't work on a PCE even with an adapter.  
             (Exception: Night Creatures works.)  

   Note:  A Japanese Super System Card can be used with an American 
          TG16-CD using a PCE->TG16 adaptor.

CD/SCDs:  All known CDs work both ways without any extra hardware.

   Note:  Altered Beast CD does not work, but that's because of an 
          incompatibility with an older CD system version; it won't work
          on a PC Engine 2.0 or SCD either.

Arcade Card:   Only available on PcEngine.  Requires PcEngine->TG16/Duo
          adaptor to work on US machines.  Arcade Card Duo is for
          Duo machines.  Arcade Card Pro is for machines without
          SuperCD System built in (i.e. TG16-CD).

C: The Accessories:
-------------------
PcEngine->TG16/Duo Adaptors:
     -Some existing adapters, namely the WH-301 purple adapters, aren't 
      shaped to fit in a Turbo Duo or Turbo Express without some 
      modification.  It is also suspected that the WH-301 will not work at
      all with the LaserActive machines.  There are three solutions:  
         1) Find one that fits.  There is a "Kisado" type adaptor made in
            part by FAQ contributor David Shadoff.  This is a streamline 
            adapter that fits well in TG16/TGExp/DUO machines without any 
            modification.  Here's a schematic of it (not drawn to scale):

     +------------------------------------+_+----+#######+   Top View
     |======                                     |#######|
     |======                                     |#######|
     |======                                     |#######|
     |======                                     |#######|
     |======                               _     |#######|
     +------------------------------------+ +----+#######+

     <-- Machine End                        HuCard End -->
                                   
                                                   ------\  Side View
                                                     ______|   
     =======-------------------------------v-------------/
                               
                               ^---Notch for power switch

The card itself is about 75% longer than a standard HuCard, and when
a HuCard is placed in, it leaves about .5 cm between the HuCard and the
machine.

If you are having trouble with the 301 type adapters, then you may want 
to track down one of these beasts.  They are currently being re-manufactured
because of recent interest in them.  Contact David Shadoff (daves@interlog.com)

         2) remove the HuCard door off of the Duo
         3) Do some careful cutting on the WH-301 adaptor:
            Before:     ------------   After:     ____________
                   |          |         \       |
              ________|__________|         _________\________|   

PcEngine and TG16/Duo Controllers:
     -American Duo controllers are the same PcEngine controllers; they both
      have 8-pin mini-din connectors while the TG16 uses the larger 8-pin 
      dins.

     -To use a Duo/PcEngine controller on a TG16, or vise-versa, you can 
      either:
     1) Obtain an adaptor.  TTI supposedly makes TG16->Duo cables and
        mail order places like Buy-Rite make Duo->TG16 cables.
        (See also TG16->Duo joystick cable pinouts in Section 4.D)
     2) Open up a DuoPad and a TurboPad and switch the internal plugs of
        each controller.  Make sure both the internal plugs of each 
        controller are the SAME type of connectors and that the wiring 
        order are the same.  As far as I know, there are two types: a thick
        blocky one and a thin one.  This technique would be useful, for 
        example, in turning a PcEngine 6-button pad into a TG16 6-button 
        pad.  You will end up with a spare Duo/PcEngine 2-button 
        controller.  
        Note:  Supposedly, this technique can apply to TurboTaps and
            DuoTaps as well.
        =======  
     ***WARNING:  If nothing works, make sure you shut down your machine
        =======   fast or you might end up with a shorted Tap/Pad! :P

     #### Thanks to johnk@cs.utexas.edu for this section :) ####


=========================
4  Technical/System Specs
=========================

A: Machine Specs:
-----------------
Note:  I left the specs for other video game systems for comparison purposes.
#####  Spec chart from Ken Arromdee's rec.games.video FAQ:
[chart originally by Corey Kirk]
______________________________________________________________________________
|          | Neo Geo  |   SNES   | Genesis  |   TG-16  |    NES   | Sega MS2 |
|----------+----------+----------+----------+----------+----------+----------|
|Bits (CPU)|   8 + 16 |       16 |       16 |    8 + 8 |        8 |        8 |
|Bits (Gx) |       16 |       16 |       16 |       16 |        8 |        8 |
|CPU       |     68000|    65816 |    68000 |   HuC6280|     6502 |      Z80 |
|APU (Aud) |       Z80|  SPC???? |      Z80 |          |          |          |
|MHz       |   12.5, 4|      3.6 |      7.6 |  3.6  3.6|      1.8 |      3.6 |
|Graphics  | 320 x 224| 256 x 224| 320 x 224| 256 x 256| 256 x 240| 240 x 226|
| -2nd mode|          | 512 x 448|320 x 448*| 320x256**|          |          |
|Planes    |        ? |        ? |        2 |        1 |        1 |        1 |
|Colors    |4096/65536| 256/32768|   61/512 |  482/512 |    16/52 |   52/256 |
|Sprites   |      380 |      128 |       80 |       64 |        8 |       16 |
| - size   |  16 x 512|   32 x 32|   32 x 32|   16 x 16|    8 x 8 |    8 x 8 |
|Audio     |   15-lyr |PCM 8-lyr |   10-lyr |    6-lyr |     mono |     mono |
|RAM       | 64K+68Kgx|128K+64Kgx| 72K+64Kgx|  8K+64Kgx|  2K+ 2Kgx|        ? |
|          | (+2K Z80)|          |          |          |          |          |
|----------+----------+----------+----------+----------+----------+----------|
|CD CPU/MHz|        ? |          |68000/12.5| 65802/16 |
|CD RAM    |          |          |     768K |   CD=64K |
|          |          |          |          | SCD=256K |
|----------+----------+          +----------+----------+
* The 320x448 mode on the Genesis is the Sonic split-screen mode.
** A 512x256 mode is possible through fiddling with registers, but not
officially supported.

Comment: Some listings of colors are probably a bit too high.  For instance,
the Genesis has 8x8 tiles which use 16 colors from one of 4 palette's each,
which would be 64 colors, except that the 16th is a "transparent" color that
is the same for all 4.  Listings for Genesis colors tend to ignore this and
say "64" instead of "61".  It's unclear how many of the other figures are like
this.

________________________________________________________
|          |  GameBoy |   Lynx   | GameGear | TExpress |
|----------+----------+----------+----------+----------|
|Bits (CPU)|        8 |        8 |        8 |    8 + 8 |
|Bits (Gx) |        8 |       16 |        8 |       16 |
|CPU       |      Z80 |     6502 |      Z80 | 6502 6502|
|MHz (CPU) |      2.2 |      4.0 |      3.6 |      7.2 |
|MHz (Gx)  |          |     16.0 |          |          |
|ScreenSize|     2.6" |     3.5" |     3.2" |     2.6" |
|Graphics  | 160 x 144| 160 x 102| 160 x 144| 256 x 216|
|Colors    | mono (4) |  16/4096 |  32/4096 |  482/512 |
|Sprites   |        8 |    unlim |       64 |       64 |
| - size   |    8 x 8 |    unlim |    8 x 8 |  16 x 16 |
|Audio     |    2-lyr |    4-lyr |    4-lyr |    6-lyr |
|RAM       |      16K |      64K |      24K |  8K+64Kgx|
|----------+----------+----------+----------+----------|
Most systems can change colors on successive scan lines, using more colors
than the ones listed.

The existence of multiple graphics modes also confuses things--it might not be
possible to use all features at the highest graphics mode, as in the lack of
hardware rotation in the SNES 512x448 mode.  I'm not sure if there are
limitations on the double resolution Genesis mode (used for Sonic split
screen).


B: PcEngine/TG-16 HuCard pinout:
--------------------------------
This information was posted by David Shadoff (daves@interlog.com)
and is mostly verbatim:

Notes:
(1) For reference, pin 1 is the short pin (on the left, if the card
    is to inserted forwards), pin 38 is the long pin on the right.
(2) *     - means I think this is what it is
    **    - means I don't know
    (bar) - means it is an active-while low condition (usually denoted
            by a bar over top)
(3) I'm telling you all I know (which really isn't much), and it may
    contain errors, also - I will not be held responsible for errors
    in this list.  (or any damages resulting from the use of, or
    inability to use, this information, etc...)

Pin      Use
---      ---
1        **                           20       D4
2        **                           21       D5
3        A18*                         22       D6
4        A16                          23       D7
5        A15                          24       CE (bar) - chip select
6        A12                          25       A10
7        A7                           26       OE (bar) - output enable
8        A6                           27       A11
9        A5                           28       A9
10       A4                           29       A8
11       A3                           30       A13
12       A2                           31       A14
13       A1                           32       A17
14       A0                           33       A19*
15       D0                           34       R/W (bar over W) - read/write
16       D1                           35       **
17       D2                           36       **
18       Gnd                          37       **
19       D3                           38       +5V

It is interesting to note that pins 6 thru 29 are basically exact
duplicates of the functions of pins 2 thru 25 on a 2764 EPROM.
Obviously, the design of the chip's die was not a complete re-work;
it just sits on a different package.

I got this information from tracing address- and data-paths through
the PC-E to the 2K static RAM (which has a known pinout), and
extending that information by reviewing an NEC data book on their
1-Megabit factory-programmed PROM's (it's an old data book, so I
couldn't go any further).

The TG-16 differs from the PC-E in that the D0-7 datalines are
reversed (actually, the PROM is programmed that way, and the wires
leading to the data bus in the machine are reversed).  I have
shown here, the card pinout (which does not differ).  I believe
that this is the PC-E port pinout (TG-16's just reverse the data
lines' order; swap 0 for 7, 1 for 6, 2 for 5, and 3 for 4).
-
Additional information: to copy a TG-16 game to work on a PC Engine with
copier, reverse the bit order.  There is then a sequence of code which checks
what machine the game is running on: all known examples start with 78 54 A9,
have the letters NEC at offset 15 hex, and an F0 at offset 0B.  If the F0 is
changed to an 80 (changing a conditional jump to an unconditional jump), the
game will work on both PC Engine and TG-16.

This code sequence is usually at the start of the game, but can be in other
places.


C: TG16/Duo and 6-button joystick techs:
----------------------------------------
### Info from Robert Kemmetmueller <rskm@VNET.IBM.COM>:

* A regular controller has a single 74HC157 IC (16-pin) in it.  This
    is some kind of "switcher" chip (exact function unknown) that lets
    the console poll the 4 directional switches (U D L R), and then poll
    the other 4 switches (S R I II).
* A 6-button controller has three 74HC157 IC's, and a half-used
    74HC163 IC, and a transistor for the autofire circuit.
* A 6-button controller MUST have an autofire circuit.  The reason
    is, it must continuously toggle between the set (U D L R , S R I II)
    and the set (- - - - , III IV V VI).  The console never knows which
    set it'll get on any given poll, so it has to keep polling until it
    gets BOTH sets.  The way it determines WHICH set it gets is: If it's
    the second set, all four directions will appear to be pushed.

So you can see that even with a normal controller, you can fool the
console into thinking you pushed the nonexistent III IV V VI buttons, by
pushing the control pad in all four directions and pressing S R I II.
This is not physically possible due to the physical design of the
controller, but I did verify my theory by applying bits on tin foil to
all 4 directional contacts of a standard 2-button controller.


o Is it possible to make a SNES->TG16/Duo joystick converter?

::WARNING: Electrotechie mumbo-jumbo about controller guts follows::

The TG-16 controller uses a 74HC157 IC, which is a quad 2-line-to-1-line
data selector/multiplexer with noninverting output.  The console does a
"double-poll", getting the values of the U D L R pad switches once, and
then the R S I II buttons.

The Avenue6 pad uses three of those ICs, one to "double-poll" the usual
(U D L R, R S I II) buttons, another to "double-poll" the (- - - -, III
IV V VI) buttons, and the third IC continuously switches WHICH of those
( ) sets is sent when the console polls.

(The software running on the console never knows which set it'll get on
any given poll, but it can TELL which set because the "- - - -" means
all 4 directions were pushed.  Older titles don't know how to handle
that.  Watch Bomberman go spaztic when your controller is set to type
"B"!)

The other chip in the Avenue6 pad is a 74HC163, a presettable
synchronous 4-bit binary counter with synchronous clear.  I haven't
really figured out what the heck its function is in the Avenue6 pad;
it's probably just part of a glorified slo-mo/turbo circuit, which is
absolutely required for a 6-button TG16 controller to work.

SNES controllers contain two 4021B ICs, which are 8-stage parallel to
serial shift registers.

So a converter that lets you use SNES controllers on a TG16 would
require all the logic from an Avenue6-button controller, PLUS a bunch of
logic circuits (a timer? and ???) to query the SNES controller and queue
the results it serially sent back, in some buffers that the Avenue6
logic could poll at will.

So now you know why nobody's built one.  :-)


D: TG16->Duo joystick converter cable pin-out:  Submitted by Steve Marsh
----------------------------------------------  (marsh@anvil.nrl.navy.mil)

Here are the pinouts for a cable that lets you plug TG accessories
(TurboStick, TurboPad, TurboTap) into a Duo.  The TG uses DIN-8 connectors, and
the Duo uses Mini-DIN-8 connectors.  These should be available at the usual
electronics stores.  You also need an 8-conductor (plus ground/shield) cable.
Hook up the outer shell of these connectors with an additional wire in the
cable, or (preferably) the woven wire or foil shielding in the cable.  Be sure 
to make it extra long--it's tough to stretch it later!  $^)

Both diagrams below are based on looking *at* the business end; i.e. the 
DIN-8 socket view shows 8 holes, and the Mini-DIN-8 plug represents 8 little 
pins. You have to connect the wires from behind these viewpoints.  Also, if 
you are making the opposite type of cable (i.e. so you can use 6-button Duo 
pads on the TG), you'll have to do the mental gyrations yourself...  $^)


     DIN-8 SOCKET  (TG)            Mini-DIN-8 PLUG  (Duo)

      -------------                     ----##----
     /      4      \                   /    ##    \
    /  3         5  \                 /  1   7   8 \
   /                 \               |              |
  |                   |              | 6   3     5  |
  |  2      8      6  |               \            /
  |                   |                \## 2  4 ##/
   \                 /                   #------#
    \  1         7  /
     \     ###     /
      -----###-----


E: Technical Questions:  Answers given by our "local" TG16/Duo expert
-----------------------  Nimai Malle (nmalle@newssun.med.miami.edu)
                Nimai used to work for Hudson Soft in Japan as a 
                videogame programmer.  

o Could you tell us about the graphic mode in PC-engine?

Well...  (this could get length, but I'll try to summarize)
The PC-Engine and Duo machines do display 16 colors out of a possible 512
per sprite.  There are 16 palettes, each holding 16 colors.  A single sprite
can use one of those 16 palettes.  Therefore, one sprite may use one set
of 16 colors, and another a different set, hiding the limitations of the
16 color limit.  Also a sprite is 16x16 dots in size, so most object are
comprised of a set of sprites.

The PC-Engine can only display one background at a time.  The background is
made up of definable characters all 8x8 pixels in size.  The actual size of
the BG can be much larger than the display area of the TV screen, allowing
scrolling, etc.  As with sprites, there is also a set of 16 palettes, each
with 16 colors for use with BG characters.  Each character can use it's own
palette from those 16.  Which area of the BG is currently displayed on the
screen is determined by scroll registers within the PC-Engine, with (0,0)
being the upper left hand corner.  By writing new values to these registers,
the area being displayed is "instantly" changed.  To scroll, just increment
this register either in the X or Y direction.

o Does the TG-16 really have 482 colors, and a 512x262x482 mode?  

The TG-16 has 512 colors.  Some colors are necessarily duplicated.  The BG has
256 colors.  The Sprites have a separate 256 colors.  Both color spaces are 
divided into 16 palettes. 

In the BG, color 0 of all palettes are equal.  Color 0 of palette 0 determines
color 0 of all the BG palettes.  Even though these color CAN be set indepen-
dently, the screen will not reflect these settings.

In the Sprites colors, color 0 is transparent in all palettes, although it does
peek it's head in a peculiar place; beyond the display width of the BG.
Explanation: The BG display area (in it's most often used setting) is 256x216.
The display width of a television may be adjusted to squash the screen
vertically, or horizontally.  Even normal TV's show a little more that 256
TG-16 dots wide, leaving a black border on the sides.  This border color is
actually controlled by sprite color 0.  The programmer can actually set the
screen width more narrow or vertically shorter, showing more of this area.
It's only use that I've ever implemented was in measuring the CPU load of the
TG-16 during development.

All platform games work this way, basically:

MAIN LOOP
     1)Wait for vertical retrace interrupt...
     2)Check joypad, move characters, etc.
     3)Goto MAIN LOOP

So, when step 2) is reached, the screen will be redrawing at the very top.
Between steps 1) and 2) one could set sprite color 0 to RED.  Then proceed
with all the processing for the game in step 2).  Then, right before step
3), set sprite color 0 to black.  What happens is, a red area to the left
and right of the BG appears starting from the top of the screen, and continuing
down i time, until it's set black again.  The screen is drawn 60 times every
second, so if your red meter is half way down the screen, you know that your
main loop it taking half of 1/60 a second to execute.  If the red goes off
the bottom of the screen, then you've got the dreaded over-sync!!  Everything
starts moving at 1/2 speed.  If this happens right when a particular monster
enters the playing field, then you know he's the culprit.  We even got 
fancier, and showed different colors for different routines.  Now we could 
"see" our sprite drawing routine in green, say, hogging CPU time, and know 
that's where optimization should begin.

o And wouldn't the existence of this mode, combined with the Turbo Express 
resolution, mean the TE can't _really_ play all TG-16 games?  (Is this the 
Supergrafx's mode?  What _is_ the Supergrafx's mode, anyway?)

Well, NEC doesn't sanction weird resolutions.  As far as I know, there is no
setting that allows more that 256 dots vertically, but I have written games
using 512x256.  Colors are DEFINITELY fixed at 512 (minus duplicates) but when
in 512x256 mode, dithering colors, or displaying alternating vertical bands
of, say blue and red, give a convincing display of purple, so more colors 
can be SHOWN this way, but still not true color.

As for TurboExpress compatibility, I think it can handle the 320x256 mode used
in Y's and others, but I've never tested 512x256...  Interesting!
SuperGrafx is a strange beast.  It has the same CPU as the TG-16, but with two
sets of graphic control chips.  This means hex $20000 bytes of VRAM, two BG's
twice as many sprites (making 128).  BUT this meant more work for that little
CPU.  This was the complaint of most developers.  Needless to say, the system
didn't catch on, although *I* think it's games were GREAT!

o More on the Arcade card:

I wrote the Arcade Card libraries that Hudson distributes to it's developers,
so I know what this baby does!  

There are four ports to access the memory from the CPU.  Each port is one 
word.  Each port can point to a separate address in the arcade card memory.
Settings for the ports are also completely independent.  The addresses are
determined by a "base address" (3 bytes) and an "offset" (2 bytes).  Reading
and writing is possible from all ports, and each can be set to auto increment
or decrement the offset or the base address.  Also, there is a bit one can
"hit" that causes the base and offset to be added, with the result being stored
in the base.  This COULD be used as a fast 3 byte adder.  There is also a 
4 byte read/write barrel roller.  Basically, you can store any 4 byte value in
this register(s) and write the number of times you wish to shift or roll to a 
5th register and you can read the result immediately.  This is very limited, 
but a good hacker could find some tricky little application.  I was able to 
optimize division and multiplication routines, also optimized a run length 
decoder using this feature...  (I would have rather had a real multiplier and 
divider, or floating point, or something, but costs were prohibitive.)


=========================
5  Other FAQ's
=========================

o How can American HuCards be played on a Japanese PC Engine?
     Since TG16 HuCards can detect hardware differences of the PcEngine,
     TG16 HuCards cannot be played on a PcEngine.  But since the
     price of the TG16 has come down drastically to $20-40US, it wouldn't
     be much trouble getting another machine to play your American HuCards.

o Can I back up my save memory?
     Yes you can.  You don't have to delete your high scores anymore or kill
     your precious RPG save slots with this gadget.  There is a PcEngine 
     HuCard called the Ten no Koe ("voices from the sky") Bank. Its storage 
     capacity is 4 times the size of the backup RAM in the TG16/DUO.  Pop
     in the card and you'll be able to save/load save files from a menu
     screen.  Since this is a PcEngine card, you'll need a converter to use
     it on your American machine.  This card can be found for about $50.

o Can I use my TG16-CD/Duo CD player with my computer?
     There was a SCSI adaptor TTI was working on called the DuoLink
     that would connect to the Duo HuCard slot but it never came out since 
     it would retail over $100US, while a basic CD setup for a PC could 
     be obtained for about the same amount of money.  Now, you can find
     single speed CDROMs for about $50.

o Can I use a generic AC adapter for my Turbo Express?
     The original AC adaptor for the TE works at (7V,700mA).  Your best
     bet is to use a Radio Shack Universal adapter switchable to 
     (7.5V,800mA max).  A Lynx AC adapter (9V,1000mA) will work on the
     TE but be forewarned.  Pausing a game for extended periods using this
     adaptor can cause something in the express to burn out.
     ### Thanks to Steve Marsh <marsh@anvil.nrl.navy.mil> ###

o Can a LaserActive system play TG16/Duo games?
     This system plays both laser discs and CD's, and costs $720 but
     costs $480 each for add-on module allowing Sega CD or TG16/Duo
     compatibility.  (Note that a complete Sega or Turbo CD system costs 
     less than that).  Playing PcEngine HuCards may pose some problems tho.
     See Section 3: PcEngine+Compatibility


=========================
6  Magazines
=========================

o Which American Gaming magazines provide the best coverage of the 
  TG16 gaming scene?
     Most of the major gaming magazines used to provide lack-luster coverage
     for the TG16/Duo, especially after TTI's down scaling to a mail order 
     business.  Anyway, you may wish to check out the magazines on a
     month-by-month basis for PcEngine info.  Popular gaming magazines 
     include "Videogame & Computer Entertainment", "Electronic Gaming 
     Monthly", and "Game Pro".

o Are there any Turbo only magazines available?
     Well, at least there were.  After TTI's down scaling, there was
     not really much to cover.  I'm not sure whether either two magazines
     still exist.  Someone give them a call :)

     "DuoWorld" published Bi-Monthly by L.F.P. Inc.  
     Single issues are $1.95 and a one year (6 issue) subscription is $9.95
          L.F.P. Inc.
          9171 Wilshire Blvd. Suite 300
          Beverly Hills, CA 90210
          310-858-7100

     "Turbo Force" published quarterly
     Single issues are $3.95 and a one year (4 issue) subscription is $9.99
          Turbo Force
          PO Box 7597
          Red Oak, IA 51591-0597
          1-800-444-2884

o PC Engine Magazines:  
     There are three monthly magazines devoted to the PC Engine in
     Japan.  They are:
          1) Marukashi (Win!) PC Engine
          2) PC Engine Fan
          3) Gekkan (Monthly) PC Engine (Subtitled: Monthly magazine for
             Game Freaks)
     These magazines contain mostly Japanese text (although there
     is a surprising amount of English) and contain reviews, previews, full
     colour pictures on glossy paper.  They can be purchased at most
     Japanese bookstores for about $7-$8 each.  Some mail order Game
     businesses sell them for about $12-15 each.


=========================
7  Shopper's Guide
=========================

It would be a good idea to check the ads in an American video game magazine.
If you know someone who lives or who is going to Japan, Taiwan or Hong Kong, 
it would be a very good idea for him/her to get your Japanese games for you.
Especially for used games, you can get some pretty good titles for very good
prices.  (i.e. My friend found Dracula X for $250HK used, about $32US)

###OLD### Turbo Technologies, Inc.
          6701 Center Drive West, Suite 500
          Los Angeles, CA  90045
          310-641-4622 (main office)
          310-574-3304 (customer service)
          1-800-366-0136 (Info Line)

###NEW### Turbo Zone Direct
          13348 Beach Ave
          Marina del Rey, CA  90292
          Tel: 310-574-3300 (note the similarity in phone numbers?)
          Fax: 310-574-3307

Mail Order:  (Third Party Distributors)
          Totally Turbo:      1-800-368-0054

          Turbo Zone:         1-800-995-9203


Other sources for games:
     TTI has called back most of it games from its distributors and has
     turned into a mail order business.  If you want to get the newer games,
     you're gonna have to get them direct or hope some mail order places
     like Buy-Right have them.  Some of the following places still sell 
     them at discount prices tho.  Go check!  According to an old ad by 
     TTI, the following places sell (or used to sell) the TG16/Duo and 
     software: Toys R Us, Babbages, Electronic's Boutique, The Good
     Guys, McDuffs, Software /etc, Video Concepts, Walden Software, and
     through the Sears Catalog.  Other known retailers include Chips &
     Bits.

Sources for Japanese games:
     Just remember that you need an adapter for HuCard games...
     (A more complete list is available in the Japanese Videogame Sources 
     list.  See the Other Sources of Info section for more info)

See also the TurboGrafx-16/Duo/PC-Engine Mail Order FAQ maintained by 
Jeff Hildebrand (jhildebr@mbnet.mb.ca).  It can be found on the TG16/Duo 
Mailing List server or received upon request.

          Die Hard
          --------
          19640 Ventura Blvd.
          Tarzana, CA 91356
          Orders/Info/Cust.Service: 818-865-2599
          Calling this number gets the customer service/new release/
          order personnel (they have a automated message thing set up so 
          that you can hear about all the new PCE titles that they'll be
          getting in).

          Gametronix
          ----------
          1606 Quarter Path
          Richmond, TX 77469
          Orders: 713-341-6868

               Game Dude
                ---------
                PO Box 8325EG
                Van Nuys, CA 91409
                Orders: 818-764-2442

                Game Express
                ------------
                11390 Ventura Blvd., Suite 1
                North Hollywood, CA 91604
                Orders: 818-760-4263

                Marketing International
                -----------------------
                19 Milliken Blvd.
                Scarborough, Ontario Canada M1V 4A2
                Orders: 416-321-6516


          Buy-Rite Video Games
          --------------------
          PO Box 99743             1924 Captial Boulevard
          Raleigh, NC 27624        Raleigh, NC 27604
          Orders: 919-850-9473          919-834-1355
          FAX: 919-872-7561
          ATTN:     Mark
          Highly recommended not only because of their good selection
          of Japanese Hucards/CD's, but because they're friendly ;)

          Buy-Rite game list can be found on the WWW.  Use the following
          URL to access:  Compiled by Y. Wei (ywei@eos.ncsu.edu)
          http://www2.ncsu.edu/eos/users/y/ywei/www/buyrite.html


=========================
8  Other sources of info
=========================

NOTE: A "list" is not a mailing list unless it SAYS "mailing list"

TG16/Duo mailing list: Probably the best source of TG16/Duo info you can find
     out there.  Current topics about the TG16/Duo discussed.  Server 
     provides access to game reviews, cheats, game translations, faqs and 
     other info (and this FAQ too! :)  
     To subscribe:  Send mail to turbo-list-request@cpac.washington.edu
               with "subscribe" on subject line or on the first
               line of your email.  You will be subscribed into the 
               mailing list and will be emailed some info on how to 
               use the server.
               
Turbo Mailing List's Home Page on the World Wide Web:
     Maintained by Jeff Hildebrand (jeffh@iris.mb.ca, jhildebr@mbnet.mb.ca)
     The URL is:    http://www.mbnet.mb.ca/~jhildebr

Game Zero Home Page on the World Wide Web:
     Maintained by gmezero@gz.bomb.com
     The URL is:    http://www.primenet.com/~gmezero

Michael Mahon's Home Page on the WWW:
     Maintained by Michael Mahon (mmahon@kaiwan.com)
     The URL is:    http://www.kaiwan.com/~mmahon

Hudson Soft Hucard Release list:  
     Maintained by Michael Mahon (mmhaon@kaiwan.com)
     Can be found on Turbolist Server, above URL, or 
     FTP to: kaiwan.kaiwan.com in directory /users/mmahon

The TurboGrafx-16/TurboDuo/PCEngine Save Game FAQ
     Maintained by Barry Cantin (KerPlunk33@aol.com)

rec.games.video Video game FAQ:  Maintained by Ken Arromdee
                     (arromdee@jyusenkyou.cs.jhu.edu)

Anime video games list/FAQ:  Maintained by Ken Arromdee 
                    (arromdee@jyusenkyou.cs.jhu.edu)

Digital Games Review Digest: To subscribe, send mail to digital-games@
     digital-games.intuitive.com.  To obtain back issues, send mail to
     info@limbo.intuitive.com containing the lines "help" and "listall 
     Digital.Games".

QuickTime anime videos:  Maintained by Mark Johnson (mjohnson@sol.UVic.CA)
                ftp to venice.tcp.com in directory 
                /pub/anime-manga/anim/qt
                QT videos of the intro of Ranma1/2 pt2 and
                Comic Fantasy MD-CD series.  
                
Street Fighter II archive/FAQ: available on altair.krl.caltech.edu in
     /pub/sf2.  This also has a lot of other moves lists.

Video game FAQs FTP site:  Maintained by Andy Eddy (vidgames@netcom.com)
                  Senior Editor, GamePro Magazine 
                  ftp to ftp.netcom.com in directory 
                  /pub/vi/vidgames/faqs

PcEngine Fan Scans:  Maintained by Wing H. Yi (yokosima@netcom.com)
               ftp tp ftp.netcom.com in directory:     
          pub/yo/yokosima/misc        -videogame/anime/manga-related stuff
          pub/yo/yokosima/incoming   -uploads
               pub/yo/yokosima/h          -other stuff


-------------------------------------------------------------------------------
Here are some old sources for info.  There are more updated info found
on the TG16/Duo Mailing list server or from those sources above.
-------------------------------------------------------------------------------

TG16 FAQ: maintained by Steve Pearl (pearl@remus.rutgers.edu)
          This FAQ is kinda outdated.  (That's why i made this one)
          But you may want to look at it anyway.
              Can be obtained by ftp from remus.rutgers.edu in
              /pub/anime/faq/tg16/tg16.faq.Z
              Site includes some other TG16 related stuff as well.

PC Engine Game Directory: A listing of all known PC Engine games with 
        as much information on them as possible.  Maintained by Steve Pearl
        (pearl@remus.rutgers.edu) Posted monthly.  Available by email upon 
        request.

TG16 Product/Price list: A listing of all current TG16 games and a 
        survey of prices from various retail sources.  Maintained by
        Steve Pearl (pearl@remus.rutgers.edu) Posted monthly. Available by
        email upon request.

Japanese video game source list: maintained by Steve Pearl 
        (pearl@remus.rutgers.edu).  The list can be ftp'ed from 
        romulus.rutgers.edu (128.6.13.2)

:)
*******************************************************************************


