by Ben Phister, CATS In the coming months Commodore plans to begin delivery of the A570 drive. This CD-ROM peripheral for the Amiga 500 and Amiga 500 Plus should rapidly expand the installed base of CDTV-compatible players. With over 3 million Amigas sold worldwide, the potential for the A570 is enormous. The A570 presents exciting opportunities for CDTV developers. It also presents a certain number of challenges. Great efforts have been made to ensure compatibility of titles for both platforms. However, there are numerous differences between the CDTV and the A570: keyboard plus mouse vs. remote control, TV sets in a living room vs. RGB monitors on a desktop, Kickstart 2.04 vs. Kickstart 1.3, etc. With the availability of the optional keyboard for CDTV players, many users now attach a keyboard to their CDTV. Other users have attached CD-ROM peripherals to their Amiga 2000 or A3000 computers, and need keyboard support from titles. To ensure strong sales of your title on all the systems capable of playing CDTV discs, your title should take advantage of the new features of the A570, yet remain easy-to-use on the CDTV player. This article discusses the differences between the two systems, and presents extensions to the CDTV User Interface Guidelines to allow titles to run on both platforms. Physical Differences Operating System Issues Emulating the Remote Controller Screen Design Issues Three Levels of Support for the A570 Conclusion