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Tr3vor
May 16th, 2017, 07:54 PM
So I got this memory board and I'd like to use it in my AT. It came in the mail with all the dip switches off, and through my pleb tier google-fu, I was unable to find any sort of manual or any information on this board.

http://i.imgur.com/unEG9yqh.jpg

After a while of goofing around with it, I was able to get it to fill out the last 128k of my base memory, but in some games it gives some very slight video corruption, so I think something is wrong here, whether it's the random switch settings or bad memory. Also the board appears to have 2mb of memory installed, so only being able to use 128k is kind of a waste.

Does anyone have any idea of what this board is or any information about the dip switch settings?

Syclops
May 16th, 2017, 11:13 PM
Did it come with the Software / Drivers ?

modem7
May 17th, 2017, 01:34 AM
Another 8-bit 2MB Quadram card is the Quadram Liberty PC, pictured at [here (https://books.google.com.au/books?id=nC8EAAAAMBAJ&pg=PA38&lpg=PA38&dq=quadram+liberty+pc&source=bl&ots=cC2nxKjSLw&sig=ydw__mOSyjw-TxiOZLVYnf9WDH8&hl=en&sa=X&ved=0ahUKEwiYjfqGzvbTAhWKnZQKHYWJBY4Q6AEIJzAB#v=on epage&q=quadram%20liberty%20pc&f=false)].

Tr3vor
May 17th, 2017, 04:17 AM
Nope, it was just the board. I didn't think I'd need drivers anyway since all I really bought it for was to fill out that last 128k of base memory.

Interesting, in the article it says that the liberty boards boot faster than others because it doesn't count the memory on startup, maybe that's why I can't ever get this thing to count above 640k.

Syclops
May 17th, 2017, 05:45 AM
It kind of sounds like the Quadram Liberty PC mentioned above and referenced here in this article.

https://books.google.com/books?id=hoPbDSDNLTQC&pg=PA127&lpg=PA127&dq=Quadram+Quadmaster+dip+switches&source=bl&ots=Kepdk2-wyP&sig=8b9EGH1RGz_w0haVEfYicdqOQiw&hl=en&sa=X&ved=0ahUKEwjyquT6sPbTAhUJxoMKHbj3AagQ6AEIRDAG#v=on epage&q=Quadram%20Quadmaster%20dip%20switches&f=false

I think these are the Software Drivers mentioned in the article.

38608

This is the Software Manual, I had to attach it as a Link since I couldn't upload it because it was too big I guess.

http://www.prodatahosting.com/Quadram_QuadMaster_III_Manual.pdf

gslick
May 17th, 2017, 07:36 AM
You will never count over 640KB with an 8-bit ISA memory expansion board. It doesn't have address lines above 1MB.

Tr3vor
May 17th, 2017, 04:38 PM
It kind of sounds like the Quadram Liberty PC mentioned above and referenced here in this article.

https://books.google.com/books?id=hoPbDSDNLTQC&pg=PA127&lpg=PA127&dq=Quadram+Quadmaster+dip+switches&source=bl&ots=Kepdk2-wyP&sig=8b9EGH1RGz_w0haVEfYicdqOQiw&hl=en&sa=X&ved=0ahUKEwjyquT6sPbTAhUJxoMKHbj3AagQ6AEIRDAG#v=on epage&q=Quadram%20Quadmaster%20dip%20switches&f=false

I think these are the Software Drivers mentioned in the article.

38608

This is the Software Manual, I had to attach it as a Link since I couldn't upload it because it was too big I guess.

http://www.prodatahosting.com/Quadram_QuadMaster_III_Manual.pdf

I thought the QuadMaster software was for the QuadBoard cards, guess not. too bad that manual doesn't have any details on the hardware though.



You will never count over 640KB with an 8-bit ISA memory expansion board. It doesn't have address lines above 1MB.

Oh ok. When it comes to adding memory though ISA cards, I'm completely clueless.

gslick
May 17th, 2017, 07:25 PM
Oh ok. When it comes to adding memory though ISA cards, I'm completely clueless.

The original 8-bit expansion bus in the IBM PC and XT has 20 address lines, A0-A19 (and 8 data lines, D0-D7). The address range with 20 address lines is 2^20 = 1,048,576 bytes (1MB).

The 16-bit expansion bus of the IBM AT added 4 more address lines A20-A23 (in addition to 8 more data lines D8-D15). That increases the address range with 24 address lines to 2^24 = 16,777,216 bytes (16MB).

So to get extended memory above the 1MB boundary you need a 16-bit memory expansion board.

modem7
May 18th, 2017, 03:07 AM
Interesting, in the article it says that the liberty boards boot faster than others because it doesn't count the memory on startup, maybe that's why I can't ever get this thing to count above 640k.
The Liberty PC is intended for a PC or XT class machine. In the PC and XT, user RAM is sitting between 0 and 640K addresses, or optionally, including some expanded memory. The Power-On Self Test of the PC or XT motherboard never counts any fitted expanded memory, just what's between 0 and 640K.

So when the authors write, "the boards take time to test and install ...", I think they have installed the board's software, and it is that software reporting the Liberty PC's RAM info to the screen.

As for your AT, its Power-On Self Test also does not count any fitted expanded memory. It just counts what is between the 0 and 640K addresses, and any extended memory.


After a while of goofing around with it, I was able to get it to fill out the last 128k of my base memory, but in some games it gives some very slight video corruption, so I think something is wrong here, whether it's the random switch settings or bad memory.
From your perspective, you got the card to populate the AT's 512K to 640K address space, but maybe it is populating more than that, resulting in RAM overlap; example diagram at [here (http://minuszerodegrees.net/5160/ram/5160%20-%20Example%20RAM%20layout%20-%20Overlapping.jpg)]. That can cause 'strange' symptoms.

evildragon
May 18th, 2017, 03:28 AM
The original 8-bit expansion bus in the IBM PC and XT has 20 address lines, A0-A19 (and 8 data lines, D0-D7). The address range with 20 address lines is 2^20 = 1,048,576 bytes (1MB).

The 16-bit expansion bus of the IBM AT added 4 more address lines A20-A23 (in addition to 8 more data lines D8-D15). That increases the address range with 24 address lines to 2^24 = 16,777,216 bytes (16MB).

So to get extended memory above the 1MB boundary you need a 16-bit memory expansion board.

Well, there are tricks around this which some memory expansion boards did in fact do, picture it like a book, you have an entire book but can only see two pages at a time, but flipping through the pages allows you to see more.

Not as fast as seeing it all at once, but they did do this, by having a window of memory at a certain address, and being able to "page" through different spots.

Kinda like how my video card on my model 25 has 1MB VRAM, but is on the 8-bit ISA bus. We know that entire 1MB isn't mapped to the entire space, otherwise where would RAM live, other cards, etc? It has a window.

clh333
December 10th, 2017, 04:01 AM
I recently acquired the board pictured below. It appears to be identical to the one presented by the OP. As I was unable to determine the model from the board itself, an Internet search for more information led me to this post. I thank you all for your contributions; especially the documentation and drivers.

I have AST SixPack cards but this Quadram is new to my experience. As the documentation states that it is compatible with the LIM specification I am hopeful that I will be able to expand or extend memory above the 1 Mb physical address limit by means of the windowing / page technique.

-CH-

Pic:

42408

snowman
January 15th, 2019, 08:06 PM
I have the exact same card as the OP and yes from all the research Ive done I found that it has to be the Quadram Liberty PC. I can find no manual at all for the hardware only the software. I can also only find LIM 3.X expanded memory drivers no 4.X drivers for this.

Anyways would anyone have the switch settings for this? I PM'd the OP to see if he would share the settings which got him 128 of ram filled for conventional memory as I do need this for my pc. Thanks

snowman
January 17th, 2019, 06:03 AM
(sorry if this appears twice) I have this same quadram liberty PC card (same as the OP and as clh333). I was hoping the OP could share his switch settings which fill in the 128k to make a full 640k? I need to do the same thing with this card. Also did anyone ever find the meaning of the switches on this card? Thanks