Re: Improving a FIC 486 VAV REV A machine.
Posted on Yesterday, 06:04
The 486VAV has separate TAG- and dirty-TAG chips (10 chips in total) so a "dirty-issue" _should_ not apply.
Re: Improving a FIC 486 VAV REV A machine.
Posted on 2025-04-19, 17:22
You can double video-ram for a total of 2MB by populating the two "zippy" sockets. Mine is rev. A also and the BIOS I dumped is 1026...
Re: Soyo SY-5EH5 1.0 CPU Voltage
Posted on 2025-04-13, 18:58
If the K6-III won´t run stable, but the K6-2 does my guess would be defective electrolytics in the VRM section. In PC@Live´s picture above they are all defective. Andry, could you take some pics of your mainboard, please?
Re: Repairing a "Yoke 401-386SX-08" mainboard / 386 Split BIOS Question
Posted on 2025-04-13, 06:12
Yesterday I finally replaced the defective Intel N82231 and now floppy access is operational again. The original AWARD BIOS that was made for "Young Keeen Enterprises" (YOKE) doesn´t support user defined harddrives or 8MB RAM, so I replaced it with a "Zymos Poach" Mr. BIOS, that is far superior here …
Re: Soyo SY-5EH5 1.0 CPU Voltage
Posted on 2025-04-12, 13:17
What do the voltages behind the slashes mean?
Re: Repairing a "Yoke 401-386SX-08" mainboard / 386 Split BIOS Question
Posted on 2025-04-07, 11:05
This makes sense - at least as far as reading speed is concerned. The leaking battry had "evaporated" a lot of traces and vias, each time I thought I had fixed them all I still found further ones. The CPU, 82335 and 82331 had to be desoldered, traces underneath repaired and soldered back into place …
Repairing a "Yoke 401-386SX-08" mainboard / 386 Split BIOS Question
Posted on 2025-04-06, 13:46
At the moment I´m repairing an old "Yoke 401-386SX-08" mainboard that has a Zymos/Intel chipset. It refuses to output any BIOS codes, just hangs at "- - - -" and the "FRAME" LED constantly lit. Reset however seems to work. There are two BIOS chips 256Kb =32KB each, all address lines (A00 - A14) are …
Re: 386 Motherboard Refuses to Boot from Floppy
Posted on 2025-03-28, 05:33
Symptoms like thic can be caused by a missing "DRQ2" line, if the connection between ISA-bus and bus- / peripheral-controller is interrupted or if the controller is defective. If someone pulled an ISA card while the system was running, shorts between -12v / -5v and DRQ2 can occur and damage the …
Re: Shuttle HOT-409 L2-Cache WB performance
Posted on 2025-03-23, 20:04
Sorry, mixed that up - in memory performance you can see it: Filename DirtyTag.JPG File size 206.37 KiB Views 47 views File license Public domain Filename NoDirtyTag.JPG File size 234.16 KiB Views 47 views File license Public domain Sadly, the result is the same, no Dirty Tag on the 409, not …
Re: Gigabyte GA-5AX 4.1 blue resistor in the middle of ZIF Socket
Posted on 2025-03-23, 18:19
Probably a thermistor for monitoring CPU temperature. These are meant to get in mechanical contact with the CPU´s bottom side when a CPU is inserted. Feel free to share a photo...
Re: Shuttle HOT-409 L2-Cache WB performance
Posted on 2025-03-23, 18:16
All ctcm versions say unmistakably "Dirty TAG -> n/a" and in Speedsys the L2 performance is 40 MB/s reading and 20 MB/s moving, a difference that would be smaller if a Dirty TAG was active. Still, I think you are right about the DIP 20 socket, I did some measuring today and couldn´t find any …
Re: External battery on a PCChips M321 motherboard draining very fast
Posted on 2025-03-23, 16:11
I meant electrical leakage, when a capacitor´s DC isolation / resistance is too low.
Re: External battery on a PCChips M321 motherboard draining very fast
Posted on 2025-03-23, 14:43
...motherboard also looks pristine without any visible damage or defects. It´s still PC-Chips ;) Did you connect the external battery to the "EXT BAT" 4-pin header? The battery feeds the clock oscillator "4069UBP" and the CMOS in "CHIP6". Near the osc. there´s cheapo electrolytic "C2" You can …
Shuttle HOT-409 L2-Cache WB performance
Posted on 2025-03-22, 18:34
I just cleaned my old HOT-409 and did some tests with the latest BIOS. https://theretroweb.com/motherboards/s/shuttle-hot-409-ver.-2.2 As expected L2 cache mode is Write Back. I know mainboards with this chipset (OPti 495SX) that have one or two additional sockets for Dirty-TAG chips. THe HOT 409 …
Re: Biostar mb-1433/40/50uiv CMOS reset?
Posted on 2025-03-21, 15:57
Where´s L3 located? I cannot find it on my 50UIV.
Re: Supermicro P6DNH cooling question
Posted on 2025-03-19, 18:11
... but it sucks that its the middle-mounted version and not the more typical corner mount. You can say that again! Tried to find one today and while scrolling through thousands of heatsinks online I couldn´t find one single fitting here. I´ll keep my eyes open for the time being, but before I use …
Re: Supermicro P6DNH cooling question
Posted on 2025-03-19, 07:46
There´s a "i960RP" on this mainboard and the datasheet says the max. case temperature is 95°C. Filename i960rp.JPG File size 132.25 KiB Views 106 views File license Public domain There are two mounting holes near the chip so I´ll try and find a 35 x 35mm heatsink for it. I´d like to avoid using …
Re: DTK PAM-0054I E-1, help to find the characteristics of capacitors
Posted on 2025-03-19, 07:13
You can round up capacity to 2 x 100µF without any risk here.
Re: DTK PAM-0054I E-1, help to find the characteristics of capacitors
Posted on 2025-03-19, 06:36
47µF 16V. But they are probably not needed when the SRAM sockets/chips are not present. On one of the pics they are present, although no SRAMs are populated. I guess they were either dropped during the production period or they have been present on your mainboard and were removed later. The latter …
Supermicro P6DNH cooling question
Posted on 2025-03-18, 12:00
I recently found a nice P6DNH, replaced the VARTA cell, updated BIOS, did some cleaning and now everything seems to run just fine. IMG_2757a.JPG The onboard intel "i960" (33 MHz) operates in bridge mode and the upper PCI-slots are working. What´s a bit irritating is the i960 gets quite warm on the …
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