VTech Creativision (aka Funvision) specific information for cc65

Stefan A. Haubenthal

2017-11-15
An overview over the Creativision runtime system as it is implemented for the cc65 C compiler.

1. Overview

2. Binary format

3. Memory layout

4. Platform specific header files

5. Loadable drivers

6. Limitations

7. Other hints

8. License


1. Overview

This file contains an overview of the Creativision runtime system as it comes with the cc65 C compiler. It describes the memory layout, Creativision specific header files, available drivers, and any pitfalls specific to that platform.

Please note that Creativision specific functions are just mentioned here, they are described in detail in the separate function reference. Even functions marked as "platform dependent" may be available on more than one platform. Please see the function reference for more information.

2. Binary format

The standard binary output format generated by the linker for the Creativision target is a 4 KB ROM image. To create an 8 KB ROM a custom linker script has to be used.

3. Memory layout

cc65 generated programs with the default setup are 4 KB in size, occupying $B000 - $BFFF. Usable memory space for the user program is $B000 - $BEFF. $BF00 - $BFFF is reserved for the runtime and cartridge configuration area.

Special locations:

Text screen

The text screen is located at VRAM $1000.

Stack

The C runtime stack is located at $03FF and growing downwards.

RAM

The available RAM for cc65 programs of an unexpanded Creativision starts at $01FA and ends at $03FF.

Heap

The C heap is located at the end of the program's data area and grows towards the C runtime stack.

4. Platform specific header files

Programs containing Creativision specific code may use the creativision.h header file.

4.1 Creativision specific functions

5. Loadable drivers

5.1 Graphics drivers

No graphics drivers are currently available for the Creativision.

5.2 Extended memory drivers

No extended memory drivers are currently available for the Creativision.

5.3 Joystick drivers

creativision-stdjoy.joy (creativisionstd_joy)

A joystick driver for the standard joystick is available.

5.4 Mouse drivers

No mouse drivers are currently available for the Creativision.

5.5 RS232 device drivers

No communication port drivers are currently available for the Creativision.

6. Limitations

6.1 Disk I/O

The existing library for the Creativision doesn't implement C file I/O. There are even no hacks for the read() and write() routines.

To be more concrete, this limitation means that you cannot use any of the following functions (and a few others):

7. Other hints

8. License

This software is provided 'as-is', without any expressed or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.

Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.