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IBM AT 5170 Memory Error / parity error 2

OK, I got it booting again by reseating the 386 header in the 286 socket.

Modem7, would it be possible to find out which ram is bad in the above board if I move chips around?
 
offensive_Jerk said:
Modem7, would it be possible to find out which ram is bad in the above board if I move chips around?
Click to expand...
Yes. When you see the 201 error change, you will know that the faulty chip is in the last set of chips that you exchanged. Of course, use static precautions.

I am expecting (although, based on certain assumptions) that the faulty chip is in the third bank (bank 2, assuming that bank numbering starts at 0). See [here].
 
modem7 said:
Yes. When you see the 201 error change, you will know that the faulty chip is in the last set of chips that you exchanged. Of course, use static precautions.

I am expecting (although, based on certain assumptions) that the faulty chip is in the third bank (bank 2, assuming that bank numbering starts at 0). See [here].
Click to expand...

Hey Modem7, I finally added the drivers for the 386 inboard card, and the memory drivers. Does this picture mean anything to you as far as addressing? This is for the Inboard 386/AT though, the AboveBoard is still not installed.

inboard386.jpg
 
offensive_Jerk said:
Hey Modem7, I finally added the drivers for the 386 inboard card, and the memory drivers. Does this picture mean anything to you as far as addressing? This is for the Inboard 386/AT though, the AboveBoard is still not installed.
Click to expand...
By my reading of what ILIM386 is showing you, what has happened is that the 1 MB pool of RAM on the InBoard 386 card has now been split up per:

* 4 KB for "ROM mapping region" (whatever that is).
* 56 KB for "Program storage", possibly a place where some of the driver code has been stored.
* 832 KB of expanded memory (EMS).
* 4 KB of extended memory.
* 128 KB placed between addresses 512 KB and 640 KB. This is a good thing; total base memory of 640 KB.

So previously, the 1 MB pool of RAM was providing 1 MB of extended memory (between addresses 1 MB and 2 MB). Now that pool is being used for a 'bunch of things'.

Are you now seeing a 164 error at power-up? (memory size error)
 
No, no memory error. Still working OK, I just finally loaded the drivers. I was just wondering if that told you anything about how Intel does their bank numbering. Of course the Above Board will be different. I will install that later and see if the other driver says anything.
If not, I will move the chips like you said.
 
offensive_Jerk said:
No, no memory error. Still working OK, I just finally loaded the drivers.
Click to expand...
So that implies to me that at power on of the computer, the 1 MB of RAM on the InBoard 386 appears as 1 MB of extended memory (addressed between 1 MB and 2 MB). The POST sees 512 KB of base memory, and the InBoard 386's 1 MB of extended memory. Then as soon as DOS boots and the card's driver loaded, the 1 MB gets 'carved up' as specified.

offensive_Jerk said:
I was just wondering if that told you anything about how Intel does their bank numbering.
Click to expand...
No, but one of the programs supplied may be a RAM tester specifically for the InBoard 386. From what I remember, the program may draw up a crude bank diagram on-screen, highlighting any faulty RAM chip/s.

offensive_Jerk said:
Of course the Above Board will be different.
Click to expand...
It too may have been supplied with a similar program, specific to the Above Board.
 
So I put the above board back in.
Again, the POST says 02432 KB OK, 2C0004 0004 201 -MEMORY ERROR, -PARITY CHECK 2
I tried messing with the setup config for memory but was getting memory mismatch errors. When I boot to dos, I get a message that a stack fault occured at 060E:D20C.

What should I set the base memory in setup to? By base memory, do they mean the amount of memory on the motherboard (512)? Or, do they mean convential DOS memory and should I enter 640K?

And then what should I enter for expansion memory? 2048? The default that setup wanted to input was 1792KB but that didn't seem like it would be a valid config.
 
Base memory = conventional memory - so if your card is providing 128KB conventional then you need to enter 640KB.

1792 is 2048 - 256 - if one bank (256KB worth) is being used to help fill conventional memory that could be correct. I haven't used an AboveBoard, but the AT boards I've used generally wont split a bank half/half between extended and conventional.

Edit: although I just relaised the Intel Inboard386 might interfere with all that, I'm not terribly sure what you should do.
 
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This all can get confusing, particularly with RAM being supplied from multiple sources.
One thing you need to get down pat is the definitions:

Conventional (IBM's early term is 'base'):
The amount of RAM fitted between addresses 0 and 640 KB. Can come from multiple sources. In my main IBM 5170, the motherboard supplies from 0 to 512 KB, and I have a dedicated RAM card that supplies 128 KB between addresses 512 KB and 640 KB. So I have 640 KB of conventional memory.

Extended (IBM's early term is 'expansion'):
RAM past the 1 MB address. In the diagram [here] (not your InBoard by the way), there is 4 MB of extended memory. If you have multiple cards providing extended memory, there must be no gaps between that memory. Where one card finishes supplying extended memory, you configure another card to start its extended memory at that address.

Expanded memory:
Defined on WikiPedia. Not the same as 'expansion'. An important point for you is that the 5170's SETUP does not care about expanded memory. You do not need to enter that figure.


Unfortunately, Intel are confusing the matter. The 1 MB of RAM on the InBoard 386 card is a 'pool' of RAM, available to be configured for various purposes. So, Intel should ideally be using the word 'pool' or something similar, but in the display put out by ILIM386, Intel has used "extended memory".


5170 SETUP

The base (conventional) and expansion (extended) figures that you put into the 5170's SETUP are to represent the amounts of base and expansion memory that the 5170's power on self test (POST) sees at power up time, before any software has loaded.


I have things to do now. I recommend that you remove the Above Board and get back to a working memory configuration using only the InBoard 386. From behaviour that you have described earlier, at power on, the 1 MB pool of RAM on the InBoard 386 card appears as 1 MB of extended memory only. Only later when the driver loads is the pool 'carved up' for other purposes. It would be really good if someone else can confirm that, because the behaviour differs to what I remember of some other Intel cards.

If it is the case that the 'carving up' happens after the driver is loaded, then what would go in the 5170's SETUP would be:
Base = 512 KB
Extended = 1024 KB
That would represent what the 5170's POST sees at power on.
 
So I removed the Intel Inboard 386 card (and the memory that's on it) and installed the plain 286-8mhz chip that I purchased. On boot, the computer counts 512k as expected since that's all that you can install on the motherboard. I set the bios back to 512KB onboard base ram to test.
It was booting fine.

I then went downstairs and grabbed the Intel Above board memory expansion card. Now the RAM only counts to 640 on POST. I went into setup and changed the base memory to 512, and extended memory to 128. Gave a memory mismatch error upon reboot.

Went back into setup and set the base memory to 640K and extended memory to 0, and it liked that setting. No more parity errors or memory mismatch errors.

The only question I have now is, that's ALL the memory that's on the aboveboard card??? Seems like there would be MUCH more considering how many chips are on it.
 
offensive_Jerk said:
The only question I have now is, that's ALL the memory that's on the aboveboard card??? Seems like there would be MUCH more considering how many chips are on it.
Click to expand...
Why are *you* asking us how much memory is on the card? You have the card, we don't. :) How about if you count the memory chips and tell us what's actually on the card? Maybe then we can make some more progress.
 
I was getting around to posting additional pics of the card. I admit I know nothing about these old RAM chips like this. They all have different numbers and I can't find any documentation for this card.
14026902117_fe6cd93f1f_k.jpg


14026825978_24fdbd1dfa_k.jpg
 
Its normal that the system only displays 640K memory at post.

The card needs a driver , and after loading the driver the additional memory should be accessible.
Some drivers will count the additional memory when it loads and display this info on the screen.
 
OK, I'll try and get a driver. The other Intel card would show the memory on POST, so I figured this would too. I didn't know the driver needed to load.
 
offensive_Jerk said:
OK, I'll try and get a driver. The other Intel card would show the memory on POST, so I figured this would too. I didn't know the driver needed to load.
Click to expand...
Since any driver is only loaded *after* the POST I don't see how it could make a difference. Config.sys isn't read before the POST is completed.
 
With this intel above board card installed, post counts 640k.

With the intel inboard 386 card installed, post counts 1.5MB of RAM.

With no cards installed, post counts 512k of RAM.
 
So according to mikey99, the intel driver needs to load for the rest of the ram to be available. This would be after dos boots obviously. You say there is 1.25mb on the card yet.
 
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