Review: PROMISE DC-2032 Caching IDE Disk Controller

- The Lost Planet Archive -

      Nick  Kollat     4/93
      Boardman, OH
      216-726-8592
            
    Anyone using IDE (AT) interface hard drives should know about a very
interesting new controller card that (believe it or not!) will allow
your system to have 8 IDE drives of any configuration. I'm talking about
a product from PROMISE technology called  the DriveCache DC-2032 for the
ISA bus.

    This is a caching IDE controller that uses standard SIMMs for 512Kb to 16Mb
of cache RAM. One controller can control 4 IDE drives, and you can install
2 controllers per system, for up to 8 drives (pretty neat!). The board can
also control 2 floppies and 1 floppy tape (with OEM driver). There are 2
serial ports (8250-type) and 1 parallel port.

    The way the hard drive system works is as follows:

    On board are two IDE ports (Primary for drives 0 and 1, Secondary for
                                drives 2 and 3)

    Generally, drives 0 and 1 will use the CMOS drive info. and drives 2 and
3 will use a device driver (included) to configure drive parameters (I believe
you can use the driver to specify params. for drive 0 and 1 if needed). The
device driver is needed to control the secondary IDE drives and all drives of
a second DC-2032 controller if installed. This driver is only 7K in size.

    Each drive can have up to 2048 cylinders, 16 heads, and 254 sectors/track.

    You use two dual-drive data cables (not included). You must properly
jumper your drives so that each cable (IDE port) has 1 MASTER and
1 SLAVE drive.

    The cache RAM can be ENABLED/DISABLED at boot time. Another interesting
feature is that the controller can supposedly co-exist as a secondary
controller with ANY other type of controller (MFM, ESDI, SCSI or IDE)!!

    There is an on-board 8K BIOS and you can change its address via on-board
jumpers. Secondary controller IRQ is jumper-selectable. Floppy controller
can be disabled. The on-board 80186 processor senses the installed cache RAM
size.

    Several DOS utilities are provided for cache control, determining status,
secondary controller drive partitioning, and diagnostics.

Performance:

Effective access time: 0.3 msec average
Maximum data rate: 5.0 Mbytes/sec.

Max. bus speed to 16 MHz - register-level compatible with WD1003.

In practice, using this controller without SMARTDRIVE is slightly slower
than using an ordinary IDE controller WITH SMARTDRIVE. If you use SMARTDRIVE
with the DC-2032 you get a slight improvement over the DC-2032 alone (in my
opinion, this last option is not worth the memory it wastes).

    All in all, this is a solid product that is very versatile. I have been
using one as a primary controller for about 3 months (In a 486/33 AMI BIOS
machine). I have a Western Digital 2120 drive and a Western Digital 2220 drive
connected to it and it works great!

    It is my opinion that the I/O ports are a weak point on this board. It
would be more desirable (and appropriate) to use 16550A-type UARTs and have
more versatile jumper-options for these ports.

    If you shop around, street prices are in the $150-170 ballpark (no RAM).
I believe you must install at least 512K to bring up the board. There is a
lower-priced version (DC-2030) that doesn't have I/O and is not as versatile.
I don't know for sure, but I think the DC-2030 can only control 2 IDE drives.


                                                                Nick
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