Design Criteria

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Home / Hardware / Next Gen - Design Criteria

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Design Criteria

• Software Compatibility

Compatibility with existing CoCo software is quite important, and should be sacrificed only in cases where maintaining compatibility would prevent or seriously compromise new features that are agreed to be highly important, or where implementing the compatible functions would prove inordinately difficult in current technologies. Much of what makes a computer a CoCo is its ability to run CoCo software.

• Hardware Compatibility

Compatibility with existing CoCo hardware is generally desirable, though shouldn't be given as high a priority as software compatibility. It is understood that a CC-Five will be a distinct computer rather than a CoCo add-on. Some of the functionality of CoCo hardware devices that were originally optional may well be integrated into the CC-Five, making it unnecessary to provide a way for those peripherals to be connected. Original CoCo equipment is aging and scarce in comparison to ubiquitous commodity PC hardware. A CC-Five should definitely be able to use (S)VGA monitors and modern flat panel displays. The more difficult decision to be made is whether it should also support 15KHz monitors, such as the CM-8, or composite and RF modulated displays. In this instance, a display is a display, and the newer technology completely subsumes the functionality of the older (with the possible exception of using a TV as a monitor). Where these two options conflict, or compete significantly for developer resources, the preference should be toward the newer, cheaper, more abundant technology.

Some effort should be put forth to ensure that CoCo software and data files can be preserved. To that end, special consideration should be given to maintaining compatibility with CoCo media. While it is true that much of the library of old Color Computer software has already been brought forward into modern forms, such as floppy disk image files, no one knows when the next stash of old CoCo disks or tapes might be found, containing rare or entirely unique treasures from the past. While the functionality of some of these older technologies may be replaced in the base system (ie, using flash memory cards as removable media in lieu of tapes or floppy disks) the design should provide a means to gain access to old media if at all possible. The minimum level of access should be an easy way to share old media connected to a CoCo 1, 2, or 3 with the CC-Five over a serial connection. Preferable would be a way to hook up CoCo disk drives, tape drives, and cartridges directly to the CC-Five. Note that this doesn't necessarily imply built-in controllers for the media, only an infrastructure that makes it possible to add such controllers. A CC-Five with the capability to digitize audio could read CoCo cassette tapes. And if a CoCo compatible expansion bus is present, CoCo disk controllers and cartridges could be plugged into that.

• Aesthetic Considerations

Given that this will likely be a hobbyist effort which may never be available as a shrink-wrapped, consumer-oriented product, the aesthetic issues have more to do with the look and feel from a firmware and functional perspective than with a silver versus beige case. Here 'aesthetic' means, "does it feel like a CoCo?" This might include issues such as time from power-on to command prompt, and possibly consideration of default display modes, fonts, and color sets.

• Implementation Issues

The two likely implementations are software emulation under PC, MacOS, or Linux, and hardware implementation in an FPGA. Preference must be given to any hardware implementation because it is the more constrained of the two, and the more likely to embody those characteristics of the CoCo that are most CoCo-like. Emulation is, after all, emulation of some other thing, which stands as the model or standard. On the other hand, it is to be understood that in the current environment of cheap and powerful PC hardware, a software implementation of a next generation CoCo system will likely emerge before a full hardware version, and will almost certainly be much less costly, if not free. Therefore it will be much more widely available, and will likely appeal to a wider audience.

• Community Issues

Reasonable care should be taken not to alienate either CoCo users or CoCo hardware and software developers. There are few enough people still active in either category that we can't risk driving any of them away because of arbitrary design decisions.