PC-TC

Make your old PC into a thin client

You don't have to throw out the PC with the dead hard disk that's collecting dust in the corner of your office—it might be suitable for more than doorstop duty. Esprit Systems' PC-TC card can make your old PC into a thin-client terminal that requires no hard disk support and doesn't use its local hard disk or 3.5" disk drive. However, if you give your PC a terminal identity and it has a locally stored OS (e.g., Windows), you can still boot to the local OS.

Setup
I tested the PC-TC in a 350MHz AMD-K6 processor with 65MB of RAM on a 10Mbps Ethernet network. I connected this client to a server running Windows NT Server 4.0, Terminal Server Edition and Citrix MetaFrame 1.8.

The PC-TC's hardware setup instructions are excellent. I installed the card into an empty ISA slot in the test system, adjusted the system BIOS so that the computer booted from the A drive (this setup makes the system boot from the PC-TC card rather than the local hard disk), and disabled Plug and Play (PnP). I rebooted the computer, and the OS booted as expected.

According to the setup documentation, the setup program should have prompted me for the PC's client name. However, the system didn't prompt me, nor did it provide a place to enter a client name in the client setup. This inconsistency with the documentation was odd, but it didn't seem to affect the card's installation.

Setup got a little trickier at this point. Esprit Systems provided the Citrix DOS client setup instructions on a 3.5" disk in a compressed file that was so corrupt that PKZipFix couldn't open it. An Esprit Systems technical support representative express mailed the documentation to me, but in the meantime I attempted to figure out the software setup. I should have waited for the documentation, because the setup program is confusing.

The Citrix DOS client's redundancies and strange organization create part of the confusion. You set up new connections from one location and organize them from another, and TCP/IP settings are in yet another menu. In addition, the Independent Computing Architecture (ICA) client usually supports several network protocols (e.g., NetBEUI, IPX/SPX, TCP/IP), but the PC-TC card supports only TCP/IP from FTP Software. Thus, when you set up a connection, you can choose any ICA-supported network protocol; however, only FTP's TCP/IP will work. The fact that all the network protocols seem available but only one works is confusing.

Bugs and Flaws
After I finished the setup and began testing the PC-TC, I discovered a few flaws. The Enumerate menu, which should display the applications published from a MetaFrame terminal server, didn't display the published applications. However, I could connect to the published applications from the desktop after I started the connection. I asked Esprit Systems' technical support about this bug, and they responded, "Maybe it's something in the BIOS," and didn't elaborate further.

The PC-TC works with only FTP's TCP/IP, but I was irritated that the card doesn't support all the TCP/IP services that simplify working with that protocol. Although the PC-TC supports DNS and DHCP for leasing IP addresses to clients, the card doesn't support WINS, which maps IP addresses to NetBIOS names (e.g., WINS lets you call a server Froggie rather than 126.52.13.5). If you want name resolution, you must set up a DNS server. This lack of WINS support is a shame because WINS is easier to work with under NT 4.0 than DNS is.

Running a Session
After the terminal server session is up and running, it works fine in desktop mode. The desktop-mode session was stable, even when I left it running unattended overnight. (The connection-setup program didn't enumerate individually published applications, so I couldn't test an application-only session.) After you're finished using the thin client, you log off or disconnect as you do using any terminal server session. When you disconnect, you return to the DOS client connection-setup window.

If you're running a local OS and a PC-TC session, you might need to adjust your system's configuration. For example, if you don't disable Windows 98's Sleep mode when you install the PC-TC card, the system locks up when it goes into Sleep mode and requires you to reset the system to get back to the local OS. To switch between the PC-TC session and a local OS, you must power down and restart the system—the reset button doesn't work. Also, clicking Exit on the client connection-setup screen lets you exit only the client. To reboot the system, you have to power down.

Is It Worth It?
Esprit Systems' main marketing focus asserts that the product reduces your total cost of ownership (TCO) by limiting users' access to the local hard disk. The company claims that booting to the card prevents users from using any local client resources, so clients can't misconfigure their computer from the local control panel.

I'm skeptical about how much the PC-TC card cuts support costs. First, if the client system has a local OS installed, users can still boot to it by pressing Ctrl+Alt+Z during the boot process and consequently misconfigure their systems. If the PC-TC client is the only OS, users can still cause problems by playing with all the client-configuration options the card provides. For example, after I messed with connection settings, I spent a long time trying to decipher the error message Error: DDL file not found (1000). The PC-TC card isn't a one-step implementation of Zero Administration for Windows (ZAW).

Second, this solution is expensive. The cards are cheaper per seat than other terminal solutions I've encountered, but you need Citrix WinFrame, or Citrix MetaFrame and Terminal Server to run this solution. In addition, you can get DOS connectivity to a WinFrame or MetaFrame terminal server without buying the PC-TC card. And the PC-TC card doesn't provide a foolproof system.

So why buy this card? The PC-TC card is a viable option for systems administrators who plan to replace older client machines with terminals, because the card is less expensive than the cheapest Windows-based terminals (WBTs). If you plan to implement terminal services, the card is also a good way to breathe life into an old machine that has an unreliable hard disk or isn't network-ready. However, before you race out and buy the PC-TC card, think about its cost vs. how much it will really save you.