MeatballB wrote on 2024-10-03, 12:00:
Thanks for all the good ideas, have tried a few other things:
Tried a new CPU, Celeron 366/Mendocino, and gotten the same result/beeping.
OK, then CPU compatibility isn't the issue.
Tried pressing all the keys to see if there was a stuck key and even pulled the keyboard completely to check if it was a stuck key, same result/beeping.
Possibly some traces leading from the ICH to the DIN connector are damaged or something in the connector itself is damaged/shorted.
Changed the toggle switch for the FSB from Auto and tried to force both 66MHz and 100MHz, same result/beeping.
This is interesting, as both the CPUs you have tested with are 66MHz parts and neither is likely to work with 100MHz overclock. I would expect different behaviour (no happy beep for starters) at 100MHz, particularly with the Celeron 700 (no way that it would run at 1050MHz; some C366 will run at 550MHz though).
MeatballB wrote on 2024-10-03, 20:58:
So, while I'm waiting on the new RAM/GPU/VGA Header to come in to test, I'm trying to figure out a bit more about this board, specifically whether it's i810 or i810e, since that will determine whether I can use Coppermine CPUs.
No it doesn't.
Coppermine CPU support is determined by voltage support (sub-1.8V) and in the case of So370 the correct FC-PGA pinout. Chipset is irrelevant. Difference between i810 and i810E is 133MHz FSB support. Note that RAM still runs at 100MHz regardless.
The little bit I've been able to dig up leads me to believe that the base i810 can only support up to 100 MHz FSB and chips clocked up to 533MHz while the 810E can go up to 133MHz and faster chips.
Wrong and right. The "533MHz" is a reference to PPGA socket supporting only Mendocino Celeron, which - as explained above - is a physical/electrical characteristic of the socket, not of the chipset. The only difference between the chipset versions is FSB support.
Also note that there are P3 Katmai CPUs with 133MHz FSB, just as there are 66MHz FSB Coppermine Celerons and 100MHz Coppermine P3 CPUs. CPU core and FSB are not connected.
The manual for the most part just says i810, but in other sections it mentions the 133MHz FSB (with the crazy 'CPU booster') and that it supports '550, 600 MHz and higher speed Pentium II/III and Celeron processors'. So I'm really confused.
I can't quite get my head around the "CPU booster" either, particularly as it claims to boost memory to 133MHz as well. That sounds like it's just overclocking an i810 set to 1:1 memory divider to 133MHz FSB...
Maybe my eyes are going, but I can only find 2 Intel stamped chips on the board, neither of which show the Chipset number itself. One is stamped Intel FW82801AA / SL3Z2 (see image below). The other has Intel N82802A88, which I think is the firmware hub. I'm pretty sure the SL3Z2 chip is the actual chipset. Digging up that, I've found all sorts of references to the SL3Z2, even up to saying it's i815...
The FW82801AA is the ICH - i.e. the southbridge I/O controller. It is shared between multiple Intel chipsets in the 800-series. The GMCH (Intel's new name for northbridge) is under the heatsink next to socket and slot.
Any thoughts on what the actual chipset might be and what I'm looking at for max FSB / CPU compatibility?
It's either i810 or i810E, and given the manual makes no reference to i810E or to having to run memory async at 4:3 divider with 133MHz FSB CPU installed, I'd say the 810DTC has an i810. What the DTA has is anyone's guess. Until such time as you get it to post, the only way to find out is to pop off that heatink - but it's glued on so you'd have to have more thermal glue to put it back if you do that.