Atari XL Features, Disk Density, And Octave Expansion
Upon reading your review of the Summer Consumer Electronics Show (August 1983), I thought of the following questions about Atari's computers:
- Do the XL series require a plug-in BASIC cartridge, or is BASIC built-in?
- What is the physical difference between a single-density disk and a double-density disk?
- How can a single-density disk be converted to double-density?
- Are there any software or hardware packages available to increase the amount of music octaves the Atari computers can generate?
- How does the direct-connect modem included in the 1400XL and 1450XLD computers work (as far as connection goes)?
- The 1200XL requires the optional BASIC cartridge, but the new 600XL, 800XL, 1400XL, and 1450XLD all have BASIC built-in.
- The term double density can be loosely applied. It can refer to more tracks per inch (TPI), larger sector size (128 bytes versus 256), or additional tracks and sectors. In an effort to provide compatibility, Atari does not truly use double density. In effect, they added extra sectors, increasing disk storage from 90K to 127K.
- The 1050 drive can read single-density disks, so it is a simple matter of copying a file from a single-density disk to a formatted double-density disk.
- The four Atari sound generators have an eight-bit resolution, so there are only 256 possible notes, or five and a half octaves. It is possible to chain two voices together to create one voice with 16-bit resolution, permitting a nine-octave range. You can have two 16-bit voices, or one 16-bit voice and two eight-bit voices. The Advanced Music System, available from APX (Atari Program Exchange) allows 8-bit sound and can be synchronized with an external cassette recorder to let you create recorded music with more than four voices. (You play one tape through the speaker while the Atari plays music. The composite sound is then recorded on a second tape recorder.) Take a look at "16-Bit Atari Music" in the March 1983 issue of COMPUTE!.
- Direct-connect modems attach to telephones with modular jacks, either through the handset or the base. If you cannot simply unplug the cords from your telephone, you'll need to contact your telephone company. Adapters are also available from stores like Radio Shack.