Old CDC/Imprimis
                WREN and SWIFT MODEL NUMBERING SYSTEM
                    (using 94155-85P as example)


Model # digit           Description
-------------           ----------------------------
||               >>----> Facility Location
94 155-85P              94 = OK City
                        97 = Twin Cities

   ||            >>----> Series and Form Factor
94 15 5-85P             15 = Wren I   FH        20 = Wren II  HH
                        15 = Wren II  FH        21 = Wren III HH
                        16 = Wren III FH        22 = Wren V   HH
                        17 = Wren IV  FH        24 = Wren VI  HH
                        18 = Wren V   FH        35 = Swift    HH
                        19 = Wren VI  FH
                        60 = Wren VII FH

     |           >>----> Interface
9415 5 -85P             0 = SMD                 5 = ST506/412
                        1 = SCSI/SASI           6 = ESDI
                        2 = LDI                 7 = n/a
                        3 = FDI                 8 = 80286
                        4 = AT                  9 = n/a

       ||        >>----> Capacity
94155- 85 P             Unformatted capacity in Megabytes (a few
                        models had formatted capacity, here)

         |       >>----> Special Designation
94155-85 P              P = Precompensation
                        M = MacWren
                        H = High Performamce
                        D = Differential
                        S = Synchronous Spindle Capability - Wren
                        S = Synchronous SCSI - Swift
                        G = Gigabyte