sdyer@bbncca.ARPA (Steve Dyer) (10/10/83)
Well, I went out and purchased the X-Pad graphics tablet and Multi-Pak expansion interface for the TRS-80 Color Computer. It looks like the Multi-Pak interface is more powerful than Tandy's ads state--it is possible to have both the Disk controller in slot #4 and the X-Pad controller in any other slot, and use them simultaneously. It is NOT necessary to select the X-Pad's slot with a POKE. The X-Pad controller contains no ROM, merely three registers located at 6537[678]. I interpret this as meaning that any of the ROMless expansion cards available for the CoCo which provide speech synthesis, true serial ports, TOD clock or parallel printer interfaces should work fine just by plugging them in. (Not that I wouldn't get the manufacturer to agree beforehand on a return policy if this didn't work out.) The X-Pad provides the same resolution as the CoCo graphics screen, plus menu areas along the border. This (256 x 192) looks bad compared to a Summagraphics tablet, but for $200, it isn't unreasonable. The pointer device is a refillable ball-point pen. They say the refill can be replaced with a stylus for tracing, but I wouldn't know where to get one. Maybe when the ink dries out? Too bad they don't have a mouse-like device; having to constantly manipulate the pen makes it less useful for menu systems. What's more, with the expansion interface installed to allow both the disk and the tablet, the leftmost edge of the tablet sits a good foot away from the keyboard--a rather uncomfortable reach. This may just be an anomaly of my system layout. Using the device in a program is quite simple--the controller's three registers are XPOS, YPOS, and pen-status, latched 106 times/second. They also provide a program on cassette, which does a pretty good job of demonstrating how to use the tablet. The manual is OK; it's written in the same style as the two BASIC manuals-- namely at the level of an extremely bright 9 year old. /Steve Dyer decvax!genrad!wjh12!bbncca!sdyer sdyer@bbncca