Category Archives: TIGA

Hardware, TIGA

TIGA – The basic stuff

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Welcome to the TIGA basics page! The fist post in my little TIGA chapter.
You probably came here because you just got (or plan to buy) a cool, shiny TIGA card and like put it to some use. Or you’ve read about it and found out, that the Web is pretty thin on that matter… Anyway, you came to the right place!

Let’s check some points fist…

Hardware

Well, if you have a card already, great, you’re set.

There were/are different versions around. The early cards used the first implementation of the graphics controller called TMS34010  which was clocked up to 60MHz (amazingly high!). For example TIs very own “TIGA Star”:

Later models used the advanced TMS34020 which started at 33MHz up to a max of 40 but had faster instruction cycle times, a faster memory interface and a twice as big instruction cache (512 bytes. Yes, bytes). Additionally the ‘020 supports the rare TM34082 floating point co-processor (actually even more than one) to speed up 3D calculation. I’m not aware of a Tool using that…

One of the first ‘020 cards was probably the Diamond from TI, which even features a socket for the FPU:

My weapon of choice is the mighty Miro TIGER:

Every TMS340 has its own RAM to run “programs” in. Depending on the model this starts at 1MB and can sometimes expanded up to 17MB. Better cards used SIMM to do this, but there were some models which used  proprietary RAM modules which are nearly impossible to come by these days.
Next the TMS340 needs VRAM, the memory holding the graphics itself. Again, depending on the model, this might vary from 1 to 4MB resulting in different max resolutions. IMHO just 1MB doesn’t do a TIGA card justice. That is just enough for 640×480 in 24bit…
Finally, as TIGA was not a standard CGA/EGA/VGA replacement, you’ll need some way of displaying the DOS text/graphics output. TIGA was always meant as an additional display mostly using a 2nd high-resolution screen, so TIGA cards either run in parallel to an existing VGA card or it also features a (mostly simple) VGA controller for this.
Very sophisticated cards like the above miroTIGER gave many options for this. It features a small VGA part (a Cirrus Logic CL-GD540 and 256K of DRAM) to make a 2nd card unnecessary or could disable that to use a 2nd card of your choice for a two-screen-solution or offered to loop-though the signal of an existing VGA card and automatically switch between them for a single-screen-setup.

Recommendation

So if you consider buying a TIGA card, go for a TMS34020 with SIMM sockets. It should have at least 1MB RAM and 2MB of VRAM. A SPEA Graphiti FGA is a good example for this minimum config.
While DRAM isn’t that important, the more VRAM you have, the better. Having a VGA controller on board might be desirable if you’re tight on slots – but to my knowledge the best VGA controller ever used on-board  was an ET4000. So it’s more or less a matter of taste.

Software

Actually this is the more important point on your list. While yes, TIGA is a standard, it contains certain proprietary parts, called the CD, GM and EXTPRIMS you’ll need to get your card going. The reason for this is the driver which is more a layer model looking like this (listed bottom-up):

Application using TIGA (e.g. AutoCAD)
application specific extensions (also *.ALM/*.RLM file)
extended primitives (EXTPRIMS.RLM/*.ALM)
Graphics Manager (e.g. tigagm.out)
Communication Driver (tigacd.exe)

 

The 3 yellow(ish) levels are card-dependent, so without them, you’re lost and your shiny TIGA card just makes a nice paperweight.
The lowest level is the Communications Driver, or CD for short, is 100% hardware dependent –  It is always supplied by the cards manufacturer and, well, handles the low-level communication and resides in the PC (upper-)memory.
Above that sits the Graphics Manager (GM)- this is the “real thing™”, the core or kernel of TIGA – which is the firsts thing being loaded into the cards own DRAM.
On top of the Graphics Manager sits another layer belonging to the package provided by the card manufacturer and loaded into the cards RAM, the Extended Primitives Library called EXTPRIMS.RLM in 99% of all cases. This contains all the drawing routines for primitives e.g. boxes, circles but also printing text etc. The file extension ‘RLM’ stands for relocatable load modules while ALM means absolute load modules. RLM’s are loaded and linked at run time, ALM’s are linked in advance for a fixed configuration and later at run time just loaded onto the TIGA card.

Here’s another illustration to show the layer model separated by memory regions:

With these 3 layers loaded, your TIGA card is ready to rock and awaiting commands from your application. Let’s take AutoCAD as an example – it’s probably the best example anyway as TIGA was mainly used for CAD.
It will not only load the TIGA driver but probably also some extensions provided by your cards manufacturer. So for example the miroTIGER came with a 3D-Viewer called “MulitVIEW”, ELSA provided a tool called ELSAVIEW with their Gemini cards etc.. All those tools loaded some extra code into the cards RAM (that’s the light blue layer).
All the extension tools I saw up to now didn’t require more than 200KB RAM. The TIGA core itself is at ~100KB, so for most basic stuff 1MB might suffice at first – but of course some of those tools need extra RAM for holding data so my assumption is that 2MB are a good bet to start with.

Caveats

All that said, be aware that were two main versions of the TIGA kernel – V1.x and V2.x which have slight differences in programming. Again, it depends on the model of your card which TIGA version is supported. As far as I know, V2.x (2.2 being the latest) requires a TMS34020.
ALM’s were a unique feature of TIGA V1.1 and should no longer be used with TIGA V2.0. Generally, V1.x programs do not run (properly) on a V2.x CD/GM combo.

Setup

First, most likely there might be something to setup on your card. DIP switches for example or jumpers. At least you need to know/set the base-IO address of your card. Lucky are those who have a manual 😉
Next, as this is DOS-land, there are some things to set-up in your config files. As usual with DOS, you have to set an environment variable in your AUTOEXEC.BAT:

SET TIGA=-mC:\TIGA -lC:\TIGA -i0x60
PATH=%PATH%;C:\TIGA

This defines the path(es) to your TIGA modules and libraries as well as the base-IO address, at which your card is communicating. This has to be adjusted to your hardware setting.
Also the base-path to your TIGA files needs to be in the system path.

Then you load your CD and (optionally) GM:

lh C:\TIGA\TIGACD.EXE
lhC:\TIGA\TIGALNK.EXE -LX

The 1st line is clear – if your config allows, you can load the CD into upper-memory. With the 2nd line you can pre-load the GM into the cards RAM and the -LX parameter makes sure it eXecutes right after that. This step is optional, as well programmed TIGA programs check for the GM and if it’s not loaded, they’ll take care of that.

That’s about it. Yay, your TIGA system is up and running 😀 and you’re ready for some action.

The next post shows how to program your TIGA card and do some graphics…

TIGA

TIGA programming

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After we talked about the basics of the TIGA standard in the previous post, we’re now  trying to do some TIGA programming… (mind the absence of the word “useful”  😉 )

I can’t stress this enough: Compared to even the earliest 3D accelerators TIGA wasn’t fast. Actually it’s not meant to be a 3D accelerator at all, it’s a 2D accelerator which tried to cope with the slow ISA bus speed. With the arrival of VL-bus and then PCI, TIGA hadn’t had a chance – even with a TMS34082 FPU it reached a max of  160,000 polygons/sec and 25,000 shaded polygons/sec – and there’s no real support for textures. Fun fact: An original PlayStation (1, that is) did 180,000 textured and lighted polygons/sec…
Ah, and before you ask: No, there was no native Linux X11 support ever. There were two X11 servers: MetroLink offered a “stub” which translated X-call on the host to TIGA which ran on the card. And there was a DOS(!) X11 server from AGE Logic. That one ran solely inside the cards RAM, ignored TIGA completely and its speed was comparable to a Sparc 1 or Personal Iris  😕 The upside was, that was also the case on a slow i386/25 which was still usable running several tasks. So a lot of work was offloaded to the TMS340… OTOH you could invest that money in a i486 and a simple ET4000 to get the same responsiveness and got more CPU-Ooomp on top.

Demos

Anyhow, to have a quick start in TIGA programming, let’s do some demos… but before we start, make sure you can tick every point on this list:

  • You’ll need a running DOS (>= v3.2) system
  • Obviously a TIGA graphics card in an (E)ISA slot – VMs won’t take you far here.
  • A successfully loaded CD and GM (what’s that? Read the 1st TIGA post over here!)
  • A decent C compiler – I use Borland C (Turbo C v2 is fine, too) for that
  • The API documentation PDF from TI (aka “Interface Users Guide”)

…and the libraries. Those came in the so-called DDK (Drive Development Kit, download it here), which was meant to develop drivers on the DOS side of things but can also be used to write some code making use of the insane TMS340 powers 😉
This DDK contains some (thin) documentation of how to set-up your compiler and the important libraries as well as the include files.
Just unzip the archive to some place you can remember – I used C:\TIGA on my box.

Setup

There are some things to be done in the Borland/Turbo C IDE before you can compile code with the DDK.

1. Add the directory path-name of where the TIGA include files are located in the Options/Directory menu. e.g.:

Include directories: C:\TURBOC\INCLUDE; C:\TIGA\INCLUDE

2. Add the directory path-name of where the TIGA Application Interface Library files are located in the Options/Directory menu, e.g.:

Library directories: C:\TURBOC\LIB; C:\TIGA\LIBS

3. Specify the TIGA Application Interface library in the Project-Make
file. Simply add a line “AI.LIB” into your Project-Make file. No
directory needs to be specified since the path name was added to the Options/Directory menu as described above.

If you prefer to use the command-line it’s most convenient to add the paths in the call. E.g. building demo.c would result in this call:

tcc -Ic:\tiga\include -Lc:\tiga\libs -ms demo.c ai.lib

The code

Ok, so your dev-system is all set. The TI documentation is pretty good and, well, the only one you can still find these days. So make sure you gave it at least a quick glance-through. By the way, we’re only doing TIGA v2.x stuff… the DDK is not v1.0 compatible.

Have a look at Chapter 3.4. (PDF page 45), it gives a good intro how a basic TIGA application setup looks like. Basically that’s:

  • First check for a Communication Driver (CD) and then open a connection to it
  • Do your thing
  • Properly close the CD
  • exit(0);

The opening and closing of the CD are wrapped into the init_tiga() and term_tiga() functions, so I’ll use those in my samples, too. So here’s a rudimentary example without the aiding functions and #includes needed. It’s drawing a blue, solid filled rectangle, half the size of the screen, centered in the screen:

init_tiga(1);                       /* initialize TIGA*/

get_config(&config);                /* Get info on current mode */
width = config.mode.disp_hres >> 1; /* Width 1/2 screen width */
height = config.mode.disp_vres >> 1; /* Height 1/2 screen height */
xleft = width >> 1;                  /* Center rect in middle */
ytop = height >> 1;                 /* of screen */
set_fcolor(BLUE);                   /* Set foreground color */
fill_rect(width,height,xleft,ytop); /* Fill the rectangle */

term_tiga();                        /* Properly terminate TIGA */

Pretty straightforward, huh?

So without further ado, just do something more impressive: Animation!
Well, don’t wet your pants, it’s just a spinning wire-frame cube, but hey! That was quite something back in 1990 😉 It also shows the usage of extended primitives, i.e. drawing functions which might needed to be loaded onto your TIGA board first (depending on model)
The code is a bit longer, so here’s the ZIP archive, which includes a TurboC project file for your convenience, too.

As soon as I figured out, how to do decent screenshots from the TIGA frambuffer, I’ll post a piccy here.

BGI Driver

Sounds like a strange thing, but might be handy at times if you want to port your brilliant BGI application fast. And well, that’s what the BGI was meant for, right?
The driver was written in 1990 by ‘TSS Rolf Bartz’ and is most likely abandonware…

So this BGI ‘driver’ or better called a wrapper will translate BGI calls into TIGA… of course there are some limitations in speed.
Also out-of-the-box all functions use the BGI maximum of 256 colors but up to the max. resolution your TIGA card provides (well,16384×16384 is the limit ;-)).

That said, there’s a very good readme included (read it!) which not only explains how to use the driver but also tells you more about the enhancements Rolf ingeniously added:

  • There are calls for circles/ellipsoids to bypass the emulation of some calls and use genuine TIGA calls – that should speed up things quite well.
  • FillPoly uses the native TIGA call if there’s enough RAM for a workspace
  • He patched SetWriteMode so that you can use the full 24-bit TIGA color palette.

Again: This is a work-around and should not used for new projects.
If you successfully coded some demos, please let me know!

An odd end…

Finally, I’d like to share some heavy stuff: The Digital Micronics Vivid 24.

Yes, it’s an AMIGA Zorro III card, but at heart it’s TIGA… to the max! TMS34020 40MHz, two (2!) 34082 FPUs can be added, max. 8MB RAM and 16MB(!) VRAM… that’s some serious TI-o-rama. In 1992 this beast costs nearly 3000US$   😯