i820 Motherboard Roundup - January 2000

In terms of expansion, most i820 motherboards will offer very similar expansion slot configurations.  Very rarely will you see an i820 motherboard outfitted with any ISA slots.  As we mentioned in our description of the i820 chipset, the 801AA I/O Controller Hub does not support any ISA slots, but a motherboard may be outfitted with ISA slots provided that an ISA bridge is used.  However, remember that the ATX case specification only allows for 7 expansion slots to be occupied at any given time, and with most i820 motherboards shipping with no less than 5 PCI slots, taking into account 1 AGP slot and 1 AMR slot, you’ll most likely never see an i820 motherboard with more than a single ISA slot, which would be shared with its closest PCI partner. 

If you’re upgrading to the i820 platform you’re probably going to want to make the move to ditch all of your old ISA peripherals.  You should be able to replace them quite easily with superior PCI counterparts, the only exception being your modem.  Most PCI modems aren’t hardware modems, but, rather, they are software based (often referred to as Winmodems because of their dependence on the MS Windows operating system for proper operation), meaning they have very little hardware on board and rely on your CPU to do most of the work such as processing the signals sent to the modem and compressing/decompressing data.

While you can find some hardware PCI modems (such as the 3Com Internet Gaming Modem and the 3Com/USR 56K PCI Faxmodem) they typically retail for around $100 or more, so if you have a problem migrating to a PCI soft modem and don’t feel like spending the added cash for a new hardware based PCI modem then you may want to opt for a board with a single ISA slot.  Then again, broadband internet connections are flourishing in many areas so you may not even need to worry about a modem. 

Regardless of the situation, don’t plan on using more than 1 of your old ISA peripherals on an i820 motherboard.  It’s time to finally get rid of those ISA peripherals that you know you’ve been hanging on to for entirely too long ;)

Most i820 motherboards will be outfitted with around 5 PCI slots.  With a 6 PCI slot maximum of the 801AA ICH, why is it that most manufacturers will only be using 5 PCI slots?  Virtually all i820 motherboards will come equipped with an AMR slot, and, unfortunately, that AMR slot, regardless of whether you actually use it or not, occupies a slot position on the motherboard.  With the standard ATX specification only allowing for 7 slot cutouts on the back of cases and 2 slot positions already being occupied on an i820 motherboard (AMR + AGP slot), that leaves a total of 5 possible slot positions open for PCI or ISA slots. 

The truth of the matter is that most end users won’t even bother with the AMR slot.  The AMR slot is more of an OEM option than something an end user would be overly interested in.  Therefore, you can see how many users would prefer to have a 6^th PCI slot instead of an AMR slot.  There is a way around this, but very few manufacturers are offering it. 

We first noticed it on Tyan’s 810 board (S2054) - an AMR slot that was shared with a PCI slot so that you could either occupy the AMR slot or the PCI slot with a card.  This worked fine on the Tyan board because it only had 4 slots and the AMR slot was placed at the end of the board, but on a motherboard with 7 other slots, you would need an AMR card that faced the opposite direction (like an ISA card) from a PCI card in order to make use of the AMR slot.  This may be wishing for too much, but it would definitely be a much better alternative to boards with 5 PCI slots and 1 AMR slot, especially to those users that really don’t want an AMR slot.  As we mentioned before, the slot is mainly for OEMs.