Despite the memorable advertisements ("The first computer able to fit "inside" the IBM PC"), the DG-1 was only a modest success. One problem was the use of 3½" diskettes, which were slightly ahead of their time; popular software titles were not available in 3½-inch format, and this was a serious issue, because then-common diskette copy-protection schemes made it difficult for users to copy the software into that format. Additionally, the diskettes used a proprietary formatting scheme not compatible with products from other companies. Although "Creative Computing" termed the price of US$2895 "competitive", it was a very expensive system and optional additions, such as expanded RAM and an external 5¼-inch floppy drive, drove the price considerably higher. The 4.0 MHz CPU speed was fractionally slower than the then-current 4.77 MHz IBM PC. The Achilles' heel, however, was the LCD, which was not backlit, had poor contrast, and was frequently accused of serving better as a mirror than as a display screen. Usable outdoors or in bright offices only, a flashlight, it was joked, was often necessary to see the contents of the screen.