So, tried different graphics cards? 112 is getting the PCI up over 37mhz and the AGP over 74, something might not be liking this, and thus you don't get to 133.

BitWrangler wrote on 2021-11-03, 22:26:

So, tried different graphics cards? 112 is getting the PCI up over 37mhz and the AGP over 74, something might not be liking this, and thus you don't get to 133.

I hadnt - largely because the graphics seemed stable and with the P450 socket 1 CPU running at 133, there were no issues
I should add that I have run with no PCI cards, only the AGP graphics card but again, that made no difference

I see, sorry I only keep 5 or 6 things in my head at once reading through everything. Now the celeron, 1Ghz versions that ran on 1.7v were usually 66Mhz bus CPU, and those didn't clock more than one or two speed grades. Then the Katmai overclocked should be using more power than the 933 at stock speeds, however, earlier 933s had the same speed bug as the first 1G PIIIs so won't behave set much faster, but should work on 133. Slotkets are flaky when they lean askew, is it flopping around in the socket or is the retention mechanism holding it tight and straight?

BitWrangler wrote on 2021-11-03, 22:39:

I see, sorry I only keep 5 or 6 things in my head at once reading through everything. Now the celeron, 1Ghz versions that ran on 1.7v were usually 66Mhz bus CPU, and those didn't clock more than one or two speed grades. Then the Katmai overclocked should be using more power than the 933 at stock speeds, however, earlier 933s had the same speed bug as the first 1G PIIIs so won't behave set much faster, but should work on 133. Slotkets are flaky when they lean askew, is it flopping around in the socket or is the retention mechanism holding it tight and straight?

Not at all! I appreciate the help 😀
Just tried the only other AGP card I have which is a rage 128 - used with slocket a and the P933 -- behaviour is the same as with the 9250

The celeron is a SL5XU - sorry I said it was 1GHz (I was away from my kit at the time!), it's a 1.1Ghz 1100/128/100 1.75v part
The 933 is a SL5U3

The slocket is just a loose PCB so isnt held. I'll see if I can stablize it a bit.
I've cleaned the slocket's edge connectors with IPA but that didnt help.

Some ideas here.. Slotket (slot1 > s370): In need of finding retention brackets/stilts for slotket

Ah right, 1.1 celly coppermine, 100mhz stock, still a bit near the raggedy edge for what coppermine can clock to though, so don't expect to see much out of it.

BitWrangler wrote on 2021-11-03, 23:02:

Some ideas here.. Slotket (slot1 > s370): In need of finding retention brackets/stilts for slotket

Ah right, 1.1 celly coppermine, 100mhz stock, still a bit near the raggedy edge for what coppermine can clock to though, so don't expect to see much out of it.

Yeah, the celeron crashing out at 133MHz is what I'd expect 😀 that is certainly the CPU just hitting it's limit. It does seem odd that it is unstable at the stock 100MHz speed, but given that it's fine at 112Mhz, it doesnt really matter.
It's the P933 that is annoying me!
It's running fine at 112MHz at the moment in the slocket A (just run3dmark2000 and 2001SE ok) but just instability at 133 and get a load of ram errors if I run memtest in win98

Can you post the number that is on the clock generator at the left side of the AGP slot ?

EDIT
Your clock generator is likely a Cypress W48S111-14 and if that is the case then the PCI is running at 44.4 MHz with CPU @ 133MHz. This may explain some of the symptoms in your report. See page 6 in the attached spec sheet.

Post high ress pictures of bare slotkets from both sides, electric FC-PGA CPU design flaws should be apparent.

PARKE wrote on 2021-11-06, 13:33:

Can you post the number that is on the clock generator at the left side of the AGP slot ?

EDIT
Your clock generator is likely a Cypress W48S111-14 and if that is the case then the PCI is running at 44.4 MHz with CPU @ 133MHz. This may explain some of the symptoms in your report. See page 6 in the attached spec sheet.W48S111-14.pdf

Yes, that's the model of chip just next to the AGP slot on the left.
However, the fact that it is still unstable without PCI cards present makes that seem unlikely? And also, I get RAM errors on memory testing - would that fit with an unstable pci bus?
Also, it looks like at 85MHz FSB the PCI is clocked at not far off the same as it is at 133MHz (41MHz vs 44MHz) and the system is stable at that speed

(these are genuine questions! am no way an expert in any of this!)

SSTV2 wrote on 2021-11-06, 15:18:

Post high ress pictures of bare slotkets from both sides, electric FC-PGA CPU design flaws should be apparent.

Images attached, if they arent clear enough let me know and I'll try again.

Slocket A has the PGA->FC-PGA wire bodge
Slocket B has the voltage pin bodge and I added the capacitors to the unpopulated CE1 and CE2 pags - they are 10uF capacitors. They made no difference to stability

squelch41 wrote on 2021-11-06, 16:05:

Yes, that's the model of chip just next to the AGP slot on the left.
However, the fact that it is still unstable without PCI cards present makes that seem unlikely? And also, I get RAM errors on memory testing - would that fit with an unstable pci bus?

I don't know.
There is a similar chip in the upper right corner next to a jumper which is refered to as "DIMM clock buffer" in the manual. Maybe this chip acts in the same way to regulate RAM frequency and causes similar problems. But that is just guesswork on my behalf.
One point that remains is that this board was meant for Pentium II and early Pentium III. Maybe you are asking too much of the old girl.

squelch41 wrote on 2021-11-06, 16:15:

Slocket A has the PGA->FC-PGA wire bodge
Slocket B has the voltage pin bodge and I added the capacitors to the unpopulated CE1 and CE2 pags - they are 10uF capacitors. They made no difference to stability

A is supposedly a Fastfame product and B is a PCchips. Not the most desirable products for many.

PARKE wrote on 2021-11-06, 16:25:

squelch41 wrote on 2021-11-06, 16:05:

Yes, that's the model of chip just next to the AGP slot on the left.
However, the fact that it is still unstable without PCI cards present makes that seem unlikely? And also, I get RAM errors on memory testing - would that fit with an unstable pci bus?

One point that remains is that this board was meant for Pentium II and early Pentium III. Maybe you are asking too much of the old girl.

Oh, I definately am, that's the fun 😀
Just want to see if there are any avenues to push it to 133MHz -- it's just the challenge I enjoy with these old machines

squelch41 wrote on 2021-11-06, 16:32:

Oh, I definately am, that's the fun 😀
Just want to see if there are any avenues to push it to 133MHz -- it's just the challenge I enjoy with these old machines

What is the number of the chip in the upper right corner ?

PARKE wrote on 2021-11-06, 16:39:

squelch41 wrote on 2021-11-06, 16:32:

Oh, I definately am, that's the fun 😀
Just want to see if there are any avenues to push it to 133MHz -- it's just the challenge I enjoy with these old machines

What is the number of the chip in the upper right corner ?

It's W40S11-23G on the top line, then B311 1910TD
Looks like it accepts 133MHz input
"Input Frequency:............................................... 0 to 133 MHz" on the datasheet https://www.digchip.com/datasheets/parts/data … S11-23G-pdf.php

One of the other angles of attack I was looking at was with SoftFSB as this hints (as does that data sheet) that there is a way of setting the PCI clock divider to CPU/4
However, I cant work out the right settings in SoftFSB to do that -- does anyone have any ideas on that?

squelch41 wrote on 2021-11-06, 16:48:

It's W40S11-23G on the top line, then B311 1910TD
Looks like it accepts 133MHz input
"Input Frequency:............................................... 0 to 133 MHz" on the datasheet https://www.digchip.com/datasheets/parts/data … S11-23G-pdf.php

Yes, but it may be dependant on other signals to deliver the right output.
There is a photo of a later version of this board on-line and there is a jumper installed on the jumper block next to the W40S11 plus there is a switch block added at the bottom of the RAM slots next to the chip that is positioned there.
My take is that your board is not really, or really not, up for the task that you are asking of it an it is doubtful that you can overcome that via software solutions. But, I may well be wrong and when being perplexed by the behaviour of hardware is fun for you then you are on the right track 😀.

Slotket A is not fit for the FC-PGA CPU support modification, it's lacks all of the V_CMOS pull up resistors for the CMOS signal group (A20M#, FLUSH#, IGNNE#, INIT#, LINT0/INTR, LINT1/NMI, PREQ#, SLP#, SMI#, STPCLK# etc.) and most likely doesn't even have a trace which connects all of the VTT pins. Don't bother with it.

Slotket B looks more like it, but for some reason it uses 75 Ohm VTT pull up resistors instead of recommended 56 Ohm to terminate host signals from CPU, plus few resistor packs weren't even soldered. You can see that there are at least 8 resistors in the socket's cavity, which should be pulling up at least that many CMOS signals to V_CMOS, but there should be more resistors than that.

To do list for Slotket B:

*check whether all VTT pins are connected together, if not connect at least few of them to V_1.5, in order to improve current flow;
*check whether G35 and G37 pins are connected, if not, short them. If 1st requirement in the list isn't met, connect these pins to V_1.5 also;
*figure out which signals the missing resistor packs were supposed to pull up and add them if necessary;
*check whether V_CMOS (AB36) is shorted to V_1.5 (AD36) or V_2.5 (Z36) on the slotket, if it's shorted to V_2.5, remove the short (unlikely case for B, but A might have this flaw);
*make sure that V_1.5 voltage is at the right level;
*map out all of the CMOS signals that are left floating and pull them up to V_CMOS (consult intel design guides);
*improve current flow for the CPU core voltage in order to rectify undervolts. Bridge some of the Vcc and GND slotket cartrige contacts directly to the CPU socket;
*make sure that CPU uCode is up to date.

Properly modified slotket might still not guarantee you stable operation @ 133MHz FSB with PIII, due to possible MB design flaws.

SSTV2 wrote on 2021-11-06, 18:35:

Slotket A is not fit for the FC-PGA CPU support modification, it's lacks all of the V_CMOS pull up resistors for the CMOS signal […]
Show full quote

Slotket A is not fit for the FC-PGA CPU support modification, it's lacks all of the V_CMOS pull up resistors for the CMOS signal group (A20M#, FLUSH#, IGNNE#, INIT#, LINT0/INTR, LINT1/NMI, PREQ#, SLP#, SMI#, STPCLK# etc.) and most likely doesn't even have a trace which connects all of the VTT pins. Don't bother with it.

Slotket B looks more like it, but for some reason it uses 75 Ohm VTT pull up resistors instead of recommended 56 Ohm to terminate host signals from CPU, plus few resistor packs weren't even soldered. You can see that there are at least 8 resistors in the socket's cavity, which should be pulling up at least that many CMOS signals to V_CMOS, but there should be more resistors than that.

To do list for Slotket B:

*check whether all VTT pins are connected together, if not connect at least few of them to V_1.5, in order to improve current flow;
*check whether G35 and G37 pins are connected, if not, short them. If 1st requirement in the list isn't met, connect these pins to V_1.5 also;
*figure out which signals the missing resistor packs were supposed to pull up and add them if necessary;
*check whether V_CMOS (AB36) is shorted to V_1.5 (AD36) or V_2.5 (Z36) on the slotket, if it's shorted to V_2.5, remove the short (unlikely case for B, but A might have this flaw);
*make sure that V_1.5 voltage is at the right level;
*map out all of the CMOS signals that are left floating and pull them up to V_CMOS (consult intel design guides);
*improve current flow for the CPU core voltage in order to rectify undervolts. Bridge some of the Vcc and GND slotket cartrige contacts directly to the CPU socket;
*make sure that CPU uCode is up to date.

Properly modified slotket might still not guarantee you stable operation @ 133MHz FSB with PIII, due to possible MB design flaws.

Wow, thanks!
Wierldy, at least at 112Mhz, slocket A is the better behaved.
I shall get probing!