Data

Tools

Indexes

Applications

Experiments

Awesome

An open API service indexing awesome lists of open source software.

https://github.com/jacmoe/retrogardens

16bit retro programming in DosBox with Borland C++ 3.1, Turbo Pascal 7 and TASM
https://github.com/jacmoe/retrogardens

16-bit borland-cpp cpp dos dosbox pascal retro-graphics retrocomputing turbo-pascal

Last synced: 8 months ago
JSON representation

16bit retro programming in DosBox with Borland C++ 3.1, Turbo Pascal 7 and TASM

Awesome Lists containing this project

README 

          
* retrogardens [Moved to codeberg]



*Achtung*: This repository will not be updated.



If something new happens with this project, it will happen at -> https://codeberg.org/jacmoe/retrogardens



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



**Update**



[Retronew][retronew] is a modern equivalent using [Allegro][allegro].



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



# retrogardens

16bit retro programming in DosBox with Borland C++ 3.1 Turbo Pascal 7 and TASM



![palette][pal]



## Introduction



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



## Prerequisites



DosBox, Borland C++ 3.1 and Turbo Pascal 7.0.



You don't need both BCPP3.1 and TP7, so if you don't want to use Pascal, don't download and install TP7, or vice versa.



I installed TASM 5.5 also, although I am not sure if you really need to do that.  

However, below instructions assume that the Turbo Assember is installed into `C:\TASM`



Also, besure to check out Fabien Sanglard's excellent article [Let's Compile Like Its 1992][1992compile] about how to use DosBox and Borland C++ 3.1 to compile Id Software's Wolfenstein 3D, if you want a walkthrough with lots of picures and well written text.



### Where to get it

#### BC3.1 and TP7

If you don't already have BC3.1, TASM and TP7 lying around, then you can grab them from [WinWorld][winworld] - go to the *Library* section.



#### DosBox

Download it from [DosBox.com][dosbox]



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



### Dosbox

While you can read (and you probably should) the [DosBox setup and installation wiki page][dosboxwiki] , here is a list of things that I did to get up and running.



Firstly, I simply installed DosBox.



#### C drive

First, we need a place for our development tools to be installed.



In other words, we need a `C:\` drive.



I simply created a directory creatively entitled `DosBox` in my home directory.



#### General configuration



You shouldn't really have to change anything, other than outlined below.



The configuration file for DosBox is `~/.dosbox/dosbox-0.74.conf` on Linux.



Look it up if you are on other platforms.



#### Autoexec.bat

Open up the dosbox configuration file and navigate to the end, where you will find the *autoexec* section.



```

[autoexec]

# Lines in this section will be run at startup.

# You can put your MOUNT lines here.

mount c ~/DosBox

path borlandc/bin;tasm/bin;tp7/tp/bin

c:

```

We mount the C drive, set up the path and change to the C drive.



#### Floppy disks

Since we are going to program like it's 1995, we need to deal with floppy disks.



So, since our machine does not have a floppy disk station, we use floppy disk images.  

And a directory that we mount as floppy in DosBox.



So, create a directory for the floppy drive, and add a line in the `autoexec` section of the DosBox configuration file, like so:

```

mount a -t floppy ~/DOS/box_disks/floppy

```



Now, what's in the floppy disk directory will be available from the A drive inside of DosBox.



**Insert and Change floppy disks**  

Simply open a floppy image ( `disk01.img` ) in a disk image viewer, select all files and copy them to the `floppy` directory.



When the installation program asks for the next disk, simply delete the files in `floppy` and copy the files of the next disk into it.



Very low tech. But it works! :p



#### CD ROMs

If you need to mount a CD drive, and you have an iso that you want to mount, then you can do that, like so:

```

imgmount d ~/DOS/WatcomCPP10.6/watcom10.6.iso -t iso

```

When you are done with it, simply remove the line, or comment it out (in case you want to mount another iso later).



I have no idea how to swap CDs - but this is DOS and 1995  and I don't recall ever having to swap CDs when installing. :)



#### Cpu cycles

A CPU speed of 50% works well.  

Press `Ctrl+F10` to grab the input, and press `CTRL+F11` to decrease CPU cycles.  

Click `CTRL+F10` to release the mouse again.



See the [DosBox - Special Keys][dosboxspecialkeys] wiki page for a list of key combos that you can use with it.



#### DosBox Window



If you want the DosBox to be larger, you can set the size in the `[sdl]` section.



My settings are:

```

windowresolution=1024x768

output=opengl

```



You can also set autolock for the mouse to be off:

```

autolock=true



```

Then the mouse will not be grabbed automatically by the DosBox window.  

You can use `Ctrl+F10` to grab / ungrab it.



#### DosBox Oddities

If you move files around on your C directory from outside of DosBox, you need to restart it to make DOS see it.



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



### Borland C++ 3.1



#### General advise

It is a good idea to minimize the use of the mouse when using the Borland C++ IDE.



Don't click with your mouse in the DosBox window, if you don't want DosBox to grab it. Or turn off `autolock` (see above).



Use the ALT key to quickly issue commands - for example use `ALT+P ENTER` to open a project, and `ALT+R Enter` to run your project.  

**Achtung!** Do not use `CTRL+F9` to run your project, because that is the DosBox terminate key combo.



Use `ALT+[number]` to quickly switch between windows.



#### Project settings

When a project is open, enter the Options menu - `ALT+O` - and make sure that the following is set:



**Application**  

Dos Standard



**Code Generation**  

Model : Large  



**Advanced Code Generation**  

Floating Point : 80287/387  

Instruction Set : 80386  



**Entry/Exit Code Generation**  

Prolog/Epilog Code Generation : Dos standard  



**C++ Options**  

Use C++ Compiler : C++ always  



**Linker**  

Output : Standard DOS EXE  



**Debugger**

Program Heap Size : 350 K bytes  



**Directories**  

Modify the Include / Library directories as needed.  

Consider adding `C:\GARD\BC31\[project_dir]` to the Source Directories.  



My *Include Directories* is:

```

C:\BORLANDC\INCLUDE;C:\GARD\BC31\COMMON

```

My *Library Directories* is:

```

C:\BORLANDC\LIB;C:\GARD\BC31\COMMON

```



Make sure that you save the settings before exiting: `ALT+O S K`



#### ASM and Turbo Assember



#### Link shenanigans



In the `COMMON` directory, there are a couple of files in assembly code that needs to be built.



You can either do this, by first removing the object files from the projejct ( `del` ), and add the `.ASM` files ( `Ins` button in the Project window ) and build them ( `ALT+C L` ) and then remove them from the project again, and add the object ( `.OBJ` ) files again.



Or you can simply use Turbo Assembler on the command line.  

Don't ask me how to do that :p



##### TASM.EXE

If Borland complains that it can't find `TASM.EXE`, then go into `Options  - Transfer` and find `~Turbo Assember` and Edit it.  

Enter `C:\TASM\BIN\TASM.EXE` in `Program Path` and then hit the `Modify` button.



##### TASM2MSG.EXE

If Borland complains that it can't find `TASM2MSG.EXE`, find it in `C:\BORLANDC\BIN` and place a copy in `C:\BORLANDC` and a copy next to the `.ASM` file that you want to link.



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



### Turbo Pascal 7.0



Because TP7 needs to be patched to run with faster CPUs, it is a good idea to use version 7.0, and not 7.1.



#### Divide by Zero CRT runtime bug

Turbo Pascal works, but will produce executables that crashes with a *divide by zero* error at runtime.  

It will do that on faster CPUs, unless we patch it.



Download the  [Crt patch for TP7][tppatch] - get the compile time patches - and extract.  

I used the first patch, and checked my TP7 version to figure out which patch to apply (it was the first one).



Copy the files to the `bin` directory and run `PATCH PATCH700` (or PATCH701, depending on the date of your TP7).



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



## Credits

* General ideas and code from Christopher Lampton's book [Gardens of Imagination][gardens] (1994 - Waite Group) Also available from the [Internet Archive][gardens_arch]

* VGA code from David Brackeen's [256-Color VGA Programming in C][vgainc] tutorial.

* Keyboard code from Al Stevens' [Raycaster article - Dr. Dobb's Journal][raycast]



Some code from the *dos/programming* section of the [x2ftp.oulu.fi mirror][x2ftp]



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



[retronew]: https://codeberg.org/jacmoe/retronew "Retronew"



[allegro]: https://liballeg.org/ "Allegro"



[1992compile]: http://fabiensanglard.net/Compile_Like_Its_1992/index.php "Compile Like Its 1992"



[winworld]: https://winworldpc.com/ "WinWorld"



[dosbox]: https://www.dosbox.com/download.php?main=1 "DosBox - Downloads"



[dosboxwiki]: https://www.dosbox.com/wiki/Basic_Setup_and_Installation_of_DosBox "DosBox Wiki - basic setup"



[dosboxspecialkeys]: http://www.dosbox.com/wiki/Special_Keys "DosBox Wiki - Special Keys"



[tppatch]: http://www.ipnet6.org/tppatch.html "Crt patch for TP7"



[pal]: https://github.com/jacmoe/retrogardens/raw/master/screenshots/pal.jpg "Palette"



[gardens]: https://www.amazon.com/Gardens-Imagination-Programming-Maze-Games/dp/187873959X "Gardens of Imagination"



[gardens_arch]: https://archive.org/details/gardensofimagina00lamp "Gardens of Imagination from the Internet Archive"



[raycast]: http://www.drdobbs.com/windows/windows-casting-rays-and-developer-days/windows/sourcecode/windows-casting-rays-and-developer-days/30300258 "Raycaster"



[vgainc]: http://www.brackeen.com/vga/index.html "256-Color VGA Programming in C"



[x2ftp]: http://ftp.lanet.lv/ftp/mirror/x2ftp/msdos/programming/ "x2ftp.oulu.fi mirror"