Retargetable graphics (abbreviated as RTG) is a device driver API mainly used by third-party graphics hardware to interface with AmigaOS via a set of libraries. The software libraries may include software tools to adjust resolution, screen colors, pointers, and screen modes. It will use available hardware and will not extend the capabilities in any way.

The Amiga OS 3.x intuition.library is limited to 8-bit display depths, but RTG libraries make it possible to handle higher depths such as 24 bits; on Amiga there are two common APIs: Picasso 96 and CyberGraphX, which are almost compatible with each other. Both Picasso 96 and CyberGraphX require at least 4 MB RAM and a 68020 CPU to operate.

EGS and other early graphics card drivers Commodore planned to introduce retargetable graphics in future version of AmigaOS (4.0), but the company was not able to deliver such solution before its demise. Third-party graphics card manufacturers were thus forced to create their own software layers on top of AmigaOS, incompatible with each other. Most of these early Amiga graphics card drivers shared common limitations: compatibility with current applications was maintained by opening Workbench (or also other application screens, also known as "Workbench emulation") on the graphics card—usually in 16 (under AmigaOS 2.x) or 256 colours (under AmigaOS 3.x); full graphics card features like high-colour (15- or 16-bit) and true-colour (24- or 32-bit) display could be used only by applications directly programmed for such driver software. Earliest of these solutions like Grafexa and SAGE libraries were able to display only their own applications on the graphics card without any support for "Workbench emulation". Examples of other drivers are EGS, Merlin/Domino, Omnibus, Retina (which should be able even to display Workbench in 24 bit colour), Graffity, Picasso, and ProBench. Of these, Picasso offered good compatibility with older applications, because most OS-compliant programs could be promoted to graphics card display, and relatively strong software support. ProBench (by ProDev) was released as a new "Workbench emulator" for the old Merlin graphics card in 1994, and version 3 (1996) introduced 16 bit colour depth and compatibility with CyberGraphX.

Enhanced Graphics System (EGS) was developed by Viona Development using the Cluster language (a Modula-2 derivative) for Piccolo and Spectrum graphics boards, supporting screen depths up to 24 bits. It requires a minimum of RAM and of hard disk space. EGS was first presented with the EGS 110/24 card (GVP) at the World of Commodore/Amiga show in New York in April 1992. It supported a broader range of graphics cards than other drivers and was seen by some Amiga magazines as the next RTG standard for Amiga, but its compatibility with most Amiga applications was limited.

Graphic card Expansion type Graphic chip EGS 110/24 GVP LocalBus INMOS G364 framebuffer EGS 28/24 Zorro II / III Cirrus Logic GD5426 Retina Zorro II NCR 77C22E+ Visiona Zorro II IMS G300C Piccolo Zorro II / III Cirrus Logic GD5426 Piccolo SD64 Zorro II / III Cirrus Logic GD5434 Rainbow Zorro II Rainbow II Zorro II Analog Devices ADV7120 Rainbow III Zorro III Inmos G365

CyberGraphX

CyberGraphX (pronounced "cybergraphics" and often abbreviated as "CGX"), is a retargetable graphics API for the Amiga and compatible computer systems developed by Thomas Sontowski and Frank Mariak and later adopted by Phase5 for use with their graphics cards. Many other graphics card manufacturers that offered hardware for Amiga and compatible systems also used it.

Introduced in 1995 with the CyberVision64 graphics card (Phase5), CyberGraphX was the first RTG software to allow full true-colour screens for Workbench and applications—older solutions supported only 256 colours (e.g. Picasso) or a four-colour Workbench with some 24-bit windows (Retina). CyberGraphX quickly eclipsed all older graphics card drivers and by 1995 was acclaimed as the best solution for displaying Workbench and other applications. Being available free of charge for users of supported cards, it became the de facto RTG standard for Amiga. CyberGraphX V4 was the last release for AmigaOS; MorphOS uses CyberGraphX V5.

Supported graphic cards These graphic cards are supported by CyberGraphX:

Graphic card Expansion type Graphic chip PCI Avenger 3DFX Voodoo3 3000 Avenger 3DFX Voodoo3 3500 Avenger 3DFX Voodoo4 4500 Napalm 3DFX Voodoo5 5500 Napalm A2410 TMS34010 Amiga AGA Internal PCB Lisa ATI Radeon 7000VE RV100 ATI Radeon 7200 R100 ATI Radeon 7500 RV200 ATI Radeon 8500 LE R200 ATI Radeon 9000 RV250 ATI Radeon 9000 Pro RV250 ATI Radeon 9100 R200 ATI Radeon 9100 LE R200 ATI Radeon 9200 SE RV280 ATI Radeon 9200 RV280 ATI Radeon 9200 Pro RV280 ATI Radeon 9250 RV280 ATI Radeon 9600 Pro RV350 ATI Radeon 9600 XT RV360 ATI Radeon 9700 Pro R300 ATI Radeon 9800 R350 ATI Rage 128 Pro BlizzardVisionPPC Permedia 2 CyberVision64/3D Zorro II/Zorro IIIamiga.resource.cx - Amiga Hardware Database - Phase 5 Digital Products CyberVision 64/3D, read 2016-12-13 S3 ViRGE CyberVision64 Zorro IIIamiga.resource.cx - Amiga Hardware Database - Phase 5 Digital Products CyberVision 64, read 2016-12-13 S3 Trio64 CyberVisionPPC Permedia 2 DraCo Altais DracoBus Symbios Logic 77C32BLT DraCo Altais Plus DracoBus S3 Trio 64 V+ Domino PicassoII Zorro II Cirrus Logic GD5426 PicassoII+ Cirrus Logic GD5428 PicassoIV Zorro II/Zorro III Cirrus Logic GD5446 Piccolo Piccolo SD64 Cirrus Logic GD5434 Pixel64 Retina BLT Z3 Zorro III Symbios Logic 77C32BLT Spectrum XGI Volari V3XT XGI Volari V5 XGI Volari V5XT XGI Volari V8 SiS 300 / 305 SiS 315 SiS 6326

Picasso96 Picasso96 is the RTG device driver library set used by the Picasso IV and other graphics boards. Its development was started in 1996 by Village Tronic, and it is compatible with CyberGraphX.Picasso96 rtg software Although the first releases were ridden with bugs and stability problems, by version 1.17 most issues with Picasso96 were corrected. Compatibility with CyberGraphX was also improved.

Picasso96 was selected as the RTG standard for AmigaOS 4, at first released as a 68k binary in AmigaOS 4.0 pre-release, with a full PowerPC port following later in 2004 in the next OS update. AmigaOS 4.1 Final Edition (2014) integrated RTG functions directly into graphics.library.

Supported graphic cards These graphic cards are supported by the Picasso96 system available for 68K based Amiga systems:

Graphic card Expansion type Graphic chipCyberVisionPPC Custom/PCI bridge Permedia2BlizzardVisionPPCCustom/PCI bridgePermedia2 Cybervision64/3D Zorro II/Zorro III S3 Virge Cybervision64 Zorro III S3 86C764 Trio64 Domino Zorro II Tseng Labs ET4000 Merlin Zorro II/III Tseng Labs ET4000W32 oMniBus Zorro II+ISA Tseng Labs ET4000AX PicassoII Zorro IIamiga.resource.cx - Amiga Hardware Database - Village Tronic Picasso II, read 2012-08-24 Cirrus Logic GD5426 PicassoII+ Zorro II Cirrus Logic GD5428 PicassoIV Zorro II/Zorro III Cirrus Logic GD5446 Piccolo Zorro II/III Cirrus Logic GD5426 Piccolo SD64 Zorro II/III Cirrus Logic GD5434 Pixel64 Custom/AteoBus Cirrus Logic GD5434GBA PII++ Zorro II Cirrus Logic GD5434Altais Custom/DracoBus NCR77C32BLT Retina Z2 Zorro IINCR77C22E Retina BLT Z3 Zorro IINCR77C32BLT Visiona Zorro II INMOS G300 GVP EGS 110 Custom/GVP Combo CPU bus INMOS G364 EGS 28/24 Spectrum Zorro II/III Cirrus Logic GD5426 A2410 Zorro II TMS34010 RainbowII Zorro II ADV7120 FrameMaster Zorro II ADV7120 UAEgfx Host OS EmulatedVA2000 Zorro II/Zorro III Custom/FPGA ZZ9000 Zorro II/Zorro III Custom/FPGA Voodoo Banshee PCI 3dfx Voodoo Banshee Voodoo 3 PCI 3dfx Voodoo 3 Voodoo 4/5 PCI 3dfx Voodoo 4/5 Matrox PCI MGA2x64, MGA1x64, G100, G200, G400, G450/G550 Radeon PCI R100, R200 Mach64 PCI RageXL with 32bit interface IndiVision ECSv4 Denise socket Custom/FPGA pVision PCMCIA Custom/FPGA

Supported graphic cards on PPC systems

Picasso96 as used by AmigaOS 4 supports also Voodoo 3, Voodoo 4/5, and Radeon R100, R200, R300, R520 (X1000 series), R700 (HD 4000 series), HD 5000 (Evergreen) series, HD 6000 (Northern Islands) series, and HD 7000 (Southern Islands) series. The RadeonHD AmigaOS 4 driver is created and maintained by Hans de Ruiter. Ongoing development of the driver for the AmigaOS platform being exclusively funded and owned by A-EON Technology Ltd.

In 2017, rights on the Picasso96 system for classic 68K Amiga Systems were bought by Individual Computers (iComp). iComp added features such as screen dragging in version 3.0.0 and multi-monitor support in version 3.1.0 (Amiga OCS/ECS/AGA screen and RTG screen active at the same time).

RTG Master The higher level API was created by Steffen Haeuser for developing 2D and 3D games requiring chunky graphics. RTG Master supports both graphics cards (with CyberGraphX, Picasso II, Picasso96 or EGS compatible drivers) and the Amiga chipset (ECS or AGA). An example of game using RTG Master is Genetic Species.

See also

AmigaOS graphics

References