CoCoVGA has been regularly tested with the following monitors:

  • Dell 1707FPt
  • ViewSonic VE910b
  • Dynex DX-LCD-19-09

Other monitors and various projectors have been shown to be compatible as well, so long as they accept standard VGA (640x480 at 60Hz).

Some Samsung TVs and monitors require that pin 10 of the HD-15 be grounded in order to recognize that a VGA signal is present. This is not currently provided on the supplied VGA cable, although some users have created small adapters which do this to enable use of their Samsung monitor with their CoCoVGA installation. Others have been able to simply pass their CoCoVGA signal through a VGA switchbox which provides additional grounding.

Computer Systems

CoCoVGA has been shown to be electrically compatible with NTSC and PAL TRS-80 Color Computer 1 and 2 systems that have the original 6847. There is also a version of the board and FPGA design which is compatible with the already lowercase-capable 6847T1, typically marked XC80652P. It has also been installed in NTSC Tano Dragons and PAL Dragons (both 32 and 64). It also operates properly in the TRS-80 MC-10, albeit with the case ajar due to the size of the board.

The greater limitation is that these systems have various board layouts, so multiple CoCoVGA board configurations have been created, including:

  • Color Computer 1 (board marked rev F)
  • American Color Computer 2 (vertical RF can, board marked rev B)
  • Korean Color Computer 2 (horizontal RF can, either 6847 or 6847T1)
  • Tano Dragon
  • Dragon 32/64

To check that your 6847-based computer is compatible with CoCoVGA, please see System Identifcation.

SAM Accelerator

The SAM Acceleator is an accessory for CoCoVGA which takes advantage of the fact that the CoCoVGA FPGA is capable of full frame double buffering to enable the full SAM RAM and ROM high speed/double clock rate mode. To achieve compatibility of the SAM Accelerator, the following requirements must be met:

  • Version 0.92 or later of the CoCoVGA FPGA
  • 150ns RAM
  • 2MHz PIAs
  • Physical space inside your CoCo or Dragon for the SAM Accelerator board - it plugs into the 6883 (74LS783 or 74LS785) socket

Note that the 74LS785 included with the SAM Accelerator is fully backward-compatible to the 74LS783. It contains a few extra modes to support additional DRAM types.

The MC-10 does not have a SAM (6883/74LS783/74LS785) and is therefore incompatible with the SAM Accelerator.