If you plan to use BOTH an SSD and a SATA HDD in your machine you will have limited choices. The SSD REALLY should be used as a AHCI device - that's the real device type for SATA HDD's, too - so you will have to set the SATA Port Mode to AHCI. On most modern mobos that choice will apply to all SATA ports, so you can't configure one port to AHCI for the SSD, and another to IDE Emulation for your HDD.
Once that's done Win XP (and its Install routines) will not recognize the SATA HDD (now an AHCI device) because it has no built-in driver for that. How to solve that depends on what your plan is. But common to both the options below is this: your mobo came with a CD containing utilities and drivers for all its devices, and that includes the driver for Win XP to use AHCI devices. If you don't have that, OR if you think you need a more recently-released updated driver, go to the website of the mobo maker and find the EXACT mobo you have. Look around the website for updated drivers for the mobo, and find the specific one for an AHCI device or a SATA HDD. Download.
CASE 1: you plan to use the SSD as your fast "drive" that you BOOT from, and the SATA HDD will just be a second data storage device that is NOT bootable.
In this case you Install Win XP on the SSD, preferably while the HDD is NOT installed in your machine. When that is working you shut down and install the HDD. Boot up and Windows MAY tell you it found a new device that needs a driver installed. If it does not, use Start ... Control Panel ... Add Hardware to add the new drive. Point that tool to where you have the AHCI driver (on the CD or downloaded somewhere) so it can install that driver. When finished, reboot. Now use Windows Disk Management to look in its LOWER RIGHT pane (the pane SCROLLS) for the SATA HDD, which will all be Unallocated Space. RIGHT-click on that space and Initialize the drive. Most settings will be correct and I assume you will want the Partition it creates to use up ALL of the drive's space. BUT you do NOT need this drive to be BOOTABLE. Initializing can take a long time so just be patient. When it's done, back out of Disk Management and reboot, and your HDD should show up in My Computer ready to use.
Case 2: You plan to BOOT from the SATA HDD and not use the SSD for that. This requires a different procedure for installing the required driver.
The process here is a general one used for many different driver types - for example, a RAID array system. The small problem is that Win XP only knows how to load the driver from a FLOPPY disk. So to do this you need (at least temporarily) a floppy drive connected to your machine. AND you need the driver copied onto a floppy diskette in that drive.
The process is done early in a Install of Win XP onto the HDD. With ONLY that one HDD installed in your machine (not the SSD) and with your BIOS set to using the SATA ports in AHCI mode, you start the Win XP Install. Very early it will ask whether you want to install additional device drivers before proceeding. If you ignore this the option will disappear after a short time. But you should tell it yes by pressing the "F6" key. The routine will then prompt you to place the floppy diskette containing the driver(s) in the floppy drive and continue. It will install that driver and ask whether there are any more. When you've installed all the extra drivers (probably only this one) you say no and it returns to the main Install routines. What this does is customize this installation of Win XP with a "built-in" driver for the AHCI device type, and so it CAN recognize and use that SATA HDD for the Install, and from now on it WILL use the SATA HDD as an AHCI device and boot from it. So, if you install the SSD later that also wants to be an AHCI device, it will all work!