CD-ROM For The Road

We tested three double-speed and one triple-speed drive for portable applications. Two used a parallel-port interface--Disctec's RoadRunner Express and Micro Solutions' Backpack. Liberty's 115 Series CDN-P and CD Technology's Porta-Drive T4100 support SCSI and parallel-port interfaces.

The heaviest of these drives, the Backpack and the Liberty 115, weigh 4 pounds, which is equivalent to some of the desktop drives we tested (although weights for the latter went up to 14 pounds for CMS Enhancements' Platinum II). But the parallel-port interface combined with relatively light weight recommends these drives for mobility. The SCSI-based Porta-Drive T4100 was a wisp at only 1 pound.

Compared to the drives that supported EPP (enhanced parallel port) (all but the Backpack), the SCSI-based Porta-Drive T4100 provides mar ginally slower throughput and random-access speed. It shines, however, in CPU utilization by running within the MPC Level 2 specification at both 150 and 300 KBps. None of the parallel-port drives met the specification. (Note: The Liberty drive, which supports both EPP and SCSI, was tested using only the EPP interface.) This is borne out in our video tests: The Porta-Drive T4100 didn't drop any video frames in our test, while the three remaining portables dropped three quarters of the frames. If you travel to show presentations that include full-motion video, consider this drive.

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CD-ROM For The Road

                                             SEQUENTIAL
                                             THROUGHPUT   CPU UTILIZATION (%)
MODEL                                PRICE*  (KBPS)       150 KBPS   300 KBPS
CD Technology Porta-Drive T4100**    $400    300.9        19.13      49.79
Disctec RoadRunner Express CD-2x     $499    301.6        58.79      73.83
Liberty Systems 115
 Series CDN-P***  $649    311.0        45.83      94.34
Micro Solutions Backpack             $499    112.3        99.22      99.22


                                     SKIPPED                          BUFFER
                                     FRAMES        FEATURES  EASE OF  SIZE
MODEL                                (8-BIT FILE)  SCORE     USE      (KB)
CD Technology Porta-Drive T4100**    0 of 912      7.9       8.3      64
Disctec RoadRunner Express CD-2x     774 of 912    5.8       6.4      32
Liberty Systems 115 Series CDN-P***  854 of 912    8.2       8.3      256
Micro Solutions Backpack             897 of 912    5.6       6.1      32


MODEL                                DRIVE         WEIGHT    SUPPORT
                                     VENDOR        (LBS)     EPP
CD Technology Porta-Drive T4100**    Toshiba         1       ****
Disctec RoadRunner Express CD-2x     Mitsumi         3.5     ****
Liberty Systems 115 Series CDN-P***  Toshiba         4       ****
Micro Solutions
 Backpack             Mitsumi         4


*    Doesn't include adapter price; see ``Roll Call.''
**   Drive tested using SCSI port.
***  Drive tested using EPP interface.
**** = yes.

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Photograph: Clockwise (from top left): CD's Porta-Drive T4100, Disctec's RoadRunner Express, Micro Solutions' Backpack, and Liberty's 115 Series CDN-P.