So, I did a cachechk to see if had the infamous fake cache. These are the results, please can someone "translate" them to me as I''m quite a mess when it comes to this matters?
In the BIOS I have L2 Cache mode set as Wr-Back
There is not much to read on (cachechk only tested base memory, probably because of the RAM detection issue), but it looks like your cache is real.
The important bit is that there is a difference between the readings up to 256K and the value for 512K, which hints at 256KB cache at work.
To be sure, you could do a reverse test: Switch the external cache off in the BIOS, and run cachechk again, now the readings should still be 14µs up to 16K (the L1 cache of the CPU), but the rest of the line should read 40µs for all block sizes between 32 and 512K.
Also, the fact that your cache and BIOS chips are socketed is a good sign.
The output says "This machine seems to have one cache" and "cache is 16KB". The DX4 has 16K of on chip cache. It doesn't look like there's any L2 cache in this machine.
We have 2 different opinions here. Different veredicts on this?
There is a change in speed when it gets above 256KB, so that seems like an L2 cache effect. But I have no idea how much effect the cache should have on a 486 - the speed difference shown doesn't look very big.
Back in the 90s I had a 486 board with that PCChips chipset, marked "8DY" underneath the sticker. I still have the manual, but it's not the same exact board as yours. Mine had 4 30-pin SIMM slots and 2 72-pin. Still, if the chipset is the same the memory rules would probably be the same.
I was hoping the manual would help, but I think it's useless.
The manual says the max total memory is 64MB. It also claims you can use SIMM sizes of anywhere from 256KB up to 64MB (single SIMM supposedly).
Four banks of DRAM with memory size up to 64 MB using combinations of 256K, 1M, 2M, 4M, 8M, 16M, 32MB, 64MB, SIMM modules.
But I don't trust the book at all. It's the most badly written Engrish motherboard manual I've ever tried to read, and it doesn't even have a brand name anywhere, it's just called a "True GREEN" motherboard. I doubt whoever wrote the manual actually cared to get their information right.
Even later Pentium and Pentium Pro boards don't claim to support 64MB SIMMs. So that information in the PCChips 486 manual is unreliable.
That board gave me a lot of pain back then, but I wish I still had it to try experimenting with.
Here's another fine excerpt:
Memory Configuration
The DRAM sub-system contain 4 banks. Four 30-pin SIMM Socket U8 - U11 using as bank 2 : two 72-pin SIMM Socket U17 using as bank 1 and 3 ; U18 using as bank 0 and 2 . So you can not install 30-pin SIMM if using 2 banks type DRAM on to U18 and you can install 30-pin SIMM if using 1 bank type DRAM on to U18.
Yeah...
Well, did you test it with the external cache turned off in the BIOS? What were the results?
Ok 5u3, just did it. Here are the results:
As you commented before, from 32 up to 512k we can read 40µs for the block sizes (external cache disabled).
Alright! Turning off the cache shows the expected difference, it wouldn't do anything with fake cache.
The speed difference really seems not much, but this is probably the result of relaxed timings (which is not a bad idea on a PCChips board 😉)
wrote:Alright! Turning off the cache shows the expected difference, it wouldn't do anything with fake cache.
The speed difference really seems not much, but this is probably the result of relaxed timings (which is not a bad idea on a PCChips board 😉)
I'm very happy for that! Thanx a lot 5u3!
So, I haven't been able to set this 486 of mine correctly yet. Still having problems memory wise.
Today I plugged the computer into a different place, (it was in my room, I went to the living room) And to my surprise, it detected the Ram! Can it be that in my room I have too many things plugged into just one outlet?
Still, everything is a bit weird. The Ram is detected but I cannot get into most of the programs because of lack of conventional memory? That is what the computer is reporting:
a) Here's a picture of Ram detection
b) Here's the outcome of typing "MEM"
c) Here's what happens when I try to execute a program. It says that I only have 517k free of the conventional memory.
I NEED SOME HELP!!!!!!!!!!! It's amazing how much time and money I'm spending on trying to set up this bastard....
Run memmaker first and check how much conventional memory would be available after optimizing. 518kb is somewhat low for most programs.
wrote:Run memmaker first and check how much conventional memory would be available after optimizing. 518kb is somewhat low for most programs.
I've runned memmaker but it has made no changes whatsoever:
a) MEMMAKER
b) CONFIG.SYS
c) AUTOEXEC.BAT
That's a little strange. Type mem /c /p on the dos prompt, just to see what's taking up so much memory. Also you can try another memory manager like QEMM. Back in those days that I was using it, I remember having free up to 634kb of conventional memory.
wrote:That's a little strange. Type mem /c /p on the dos prompt, just to see what's taking up so much memory. Also you can try another memory manager like QEMM. Back in those days that I was using it, I remember having free up to 634kb of conventional memory.
Here you have Markk
wrote:So, I haven't been able to set this 486 of mine correctly yet. Still having problems memory wise.
Today I plugged the computer into a different place, (it was in my room, I went to the living room) And to my surprise, it detected the Ram! Can it be that in my room I have too many things plugged into just one outlet?
More likely that the physical movement of the system caused some connection to "fix" itself.
I would try to get a different motherboard if I were you.
VogonsDrivers.com | Link | News Thread
wrote:Ok guys, after reading about these "cute" Pcchips boards, and after Ram not being detected, another big question comes up.
FAKE CACHE?Oh! what a big box of surprises I'm getting with this new computer!
completely possible. My board came with real cache but permanently disabled. go figure. Run this program in dos, with NOTHING loaded: http://www.softlookup.com/display.asp?id=9029
It will tell you if your cache is working or not.
It is a mistake to think you can solve any major problems just with potatoes.
wrote:Run this program in dos, with NOTHING loaded: http://www.softlookup.com/display.asp?id=9029
It will tell you if your cache is working or not.
Did you read the thread? The OP already had a go with cachechk.
However, now that the whole memory is working again, it would not be a bad idea to run cachechk again - this time I expect it to successfully detect the L2 cache, because it should have more than one sample to work with.
About the low memory problem: It's not that programs are using so much memory: If you look at the memory listing, you'll see that there is only 40 KB of upper memory available. A typical 486 has three times as much.
Try to enable all the shadow options ("Shadow C800" to "Shadow DC00") in the BIOS setup, there is a chance that it frees more upper memory blocks.
Also, what video card do you have installed?
The CONFIG.SYS has DOS=UMB. It should be DOS=HIGH,UMB, and it probably has to be on the second line, after HIMEM but before EMM386.
I think you can use LH on MSCDEX, too. (It might be better to skip MSCDEX entirely and use SHSUCDEX, though.)
It's a bit silly MEMMAKER didn't pick up on that. I always understood it to be sort of broken.
wrote:Did you read the thread? The OP already had a go with cachechk. […]
wrote:Run this program in dos, with NOTHING loaded: http://www.softlookup.com/display.asp?id=9029
It will tell you if your cache is working or not.Did you read the thread? The OP already had a go with cachechk.
However, now that the whole memory is working again, it would not be a bad idea to run cachechk again - this time I expect it to successfully detect the L2 cache, because it should have more than one sample to work with.
About the low memory problem: It's not that programs are using so much memory: If you look at the memory listing, you'll see that there is only 40 KB of upper memory available. A typical 486 has three times as much.
Try to enable all the shadow options ("Shadow C800" to "Shadow DC00") in the BIOS setup, there is a chance that it frees more upper memory blocks.
Also, what video card do you have installed?
Hi 5u3, I have an S3 trio 64V+
I'm going to try what you said, had all shadow options disabled.
wrote:The CONFIG.SYS has DOS=UMB. It should be DOS=HIGH,UMB, and it probably has to be on the second line, after HIMEM but before EMM386.
+1
