I have this 486 motherboard (ALiKDN-1401/2C) that has fake cache on it. I find the board a bit of a novelty in itself but I was wondering if it would be possible to swap out the fake cache with real cache? I have another battery damaged 486 board with real cache that I could use as a donor...
I think what would help for those of us unfamiliar with this board is a photo of the bottom to see if there are traces leading to nowhere. I have one of the old PC Chips M919 boards with the fake SMD cache on it and a slot for a real Cache Module that looks kind of like a COAST slot but is not - the fake SMD cache is obviously fake to anyone like me who makes circuit boards - you can see the traces just loop around.
The only thing that looks fake to me, maybe, is the chips in the Cache sockets, and that's because I've never seen that brand before. Could just be some oddball chinese knockoff brand making Sub-Par chips - you see that a lot when it comes to making electronic stuff using cheap chinese parts off e-bay - like me building guitar pedals - it might be functional, just might be those chips are not performing their best.
Actually the M919 is the only case I know of fake cache with traces leading to nowhere. If you're really not sure if the mobo supports cache, take a multimeter and check if there is a voltage between where the VCC and GND pins are supposed to be. If there's one, then making fake wires with some getting power would be very strange isn't it ?
If you don't have a desoldering iron, you can simply cut the chips off and then remove each pin using a soldering iron on one side and a pair of pliers on the other side.
I have now two non PCChips boards that have/had fake cache. I added real cache on one of those and it worked without any problems, so did I with my PCChips m915. The last one has a UMC chipset and is quite fast so I will add cache to it as well.
So, I finally had some time to hook up this board again to get a BIOS dump (sorry for the delay @evasive), however, during POST it hangs on "Wait....." with POST code A1 which according to this page [1] is "Check for external cache" (or some variant of it).
These is no option in the settings to turn off L2 Cache. I also tried removing the cache jumpers, hoping that that might indicate disabled L2 Cache but no difference. It is weird it has cache jumpers to being with since the cache is soldered onto the board, you'd imagine that the cache config would be hard wired as well (if the cache is indeed real).
Edit: settings available. No difference in Cache WS either 0 or 1, same behavior. Also, these settings are different than the ones illustrated in the manual [2]
Interesting. I believe the bios could be modified to unhide the cache setting (because it's probably there and just hidden). Now there might be something else to be wrong with that board, I mean the board should boot without cache installed (why would anyone fake cache and ship a board that cannot work ?).
Maybe the cache settings are incorrect ? (By that I mean that it doesn't match any real cache chip)
Also I just thought of something you could try : since these cache chips are probably fakes, why not trying to piggyback real cache chips over the fake ones ? This should be an easy test without using any soldering iron
Okay, after some more fiddling, I got the board working. Pretty sure I booted it a year ago or so I knew it "could" work. First I tried different memory (30pin SIMMS instead of the 72pin 8MB FPM), no juice but after I changed the CPU from an Intel DX 33 to an AMD 40, voila, it came to life. No idea why the DX33 didn't work, triple checked the jumpers etc...
Anyhow, yep, cache seems to be fake. These are the results of running Ray van Tassle's CACHECHK:
1CACHECHK v4 2/7/96 Copyright (c) 1995 by Ray van Tassle. (-h for help) 2CMOS reports: conv_mem= 640K, ext_mem= 7,7168K, Total RAM= 7,808K 3Clocked at 486 40.1 MHz 4Reading from memory. 5MegaByte#: --------- Memory Access Block sizes (KB)----- 6 1 2 4 8 16 32 64 128 256 512 1024 2048 4096 <-- KB 70: 26 26 26 27 54 54 54 54 54 54 -- -- -- μs/KB 82: 26 26 26 27 54 54 54 54 54 54 54 54 54 μs/KB 93 4 5 6 7 <--- same as above 10 11Extra tests---- 12Wrt 34 34 34 34 34 34 34 34 34 34 34 34 34<-Write mem 13This machine seems to have one cache!? [read] 14 !! cache is 8KB -- 40.6 MB/s 25.8 ns/byte (199%) 4.0 clks 15 Main memory speed -- 20.4 MB/s 51.4 ns/byte (100%) [read] 7.9 clks 16 Effective RAM access time (read ) is 205ns (a RAM bank is 4 bytes wide). 17 Effective RAM access time (write) is 130ns (a RAM bank is 4 bytes wide). 18 Clocked at 486 40.1 MHz. Cache ENABLED
Also ran SPEEDTEST for good measure. This is what came that came up with:
After that I thought I run some DOOM benchmarks using Phils CompLab DOSBENCH (highest settings) for fun and since I probably never use this board again for anything useful. These are the results:
1 BUS Realticks FPS 2Jovian Logic RUBY 451 ISA 13189 5.663052544 3WD90C00 ISA 10111 7.387004253 4ATI VGA Wonder-16 ISA 10614 7.036932353 5ET4000AX ISA 7386 10.11237476 6TIGA VGA+ ET4000AX ISA 7388 10.10963725 7CL-GD5429 VLB 4559 16.38297872 8ATI Graphics Wonder VLB 4568 16.35070053 9ET4000/W32I VLB 4567 16.35428071
It runs pretty good on VLB. I assume the CPU is the bottleneck here. I also played a couple of levels of DOOM. It's totally playable on VLB, at least if I was given this board as a kid to play DOOM on I'd be happy enough.
All in all. This board is kinda weird. It seems bottom of the barrel but it has all these power saving options (totally useless in a home setting) so maybe this was more targeted at offices where it would be "on" 24/7. Not sure. The fake cache is weird but all in all it seems to perform OK if you're not a serious 1994 gamer dude.
Oh, this is a dump of the BIOS (which is dated 08/08/93):
All jumpers, connectors and whatnot line up. @pano69: can we have a bios dump? Maybe we can find out something for this KDN1401 marking.
I missed your comment re. KDN1401 marking originally.
The board seems to come in two main flavors of clock generators. Either with KDN-1401/KDN-1402C or the MX8315. The board I posted here is the KDN-1402C variant.
There is a oscillator between the ISA slots, next to it sits a chip marked KDN-1402C.
Just a thought: if your board is like one of the PcChips that had both fake and real cache versions of same exact board you may need the real cache version BIOS if you put in real cache chips..
Finding it may be tricky
Actually the M919 is the only case I know of fake cache with traces leading to nowhere. If you're really not sure if the mobo supports cache, take a multimeter and check if there is a voltage between where the VCC and GND pins are supposed to be. If there's one, then making fake wires with some getting power would be very strange isn't it ?
If you don't have a desoldering iron, you can simply cut the chips off and then remove each pin using a soldering iron on one side and a pair of pliers on the other side.
I have now two non PCChips boards that have/had fake cache. I added real cache on one of those and it worked without any problems, so did I with my PCChips m915. The last one has a UMC chipset and is quite fast so I will add cache to it as well.
Yep ! One of the PCChips required the real cache version BIOS or did not enable it even after replacing the cache but cannot remember which and cannot find it (and being AMI was a PITA to fix iirc)...
Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun
Well for pcchips boards I don't think there's any of that, they seem to detect when cache is present or not and will actually report a different message : "cache enabled" when there's no cache and "xxxkb cache detected" when there's actually cache.
Same happened on non pcchips boards.