It will be easier finding a set of matching 72pin sticks instead of finding an exact copy of the one you have now. Then again, it's a 486, so one stick of 16 MB FP ram will do the trick as well.

Which chipset does your mainboard use? If it supports EDO ram, you might even find that kind of ram cheaper and easier on marketplaces than fast page ram.

flupke11 wrote on 2020-02-24, 22:25:

Which chipset does your mainboard use?

Good question, I'll have a look in the morning. Thanks for the reply.

It's a 486, so a single 72p SIMM is a bank on its own. You don't need to pair identical modules. So long as the other module is supported by the motherboard chipset and is at least rated for the same speed (-60), you're good to go.

Shame you didn't post which motherboard you have, otherwise we could have given an authoritative answer. Also would have helped to say how many of these SIMMs you have, how many slots are free and how much RAM Duke Nukem demands.

As for the SIMM itself, NPN isn't a common DRAM brand, but googling the chip code underneath it, NN5118160AJ-60, turns up:
https://www.alldatasheet.com/datasheet-pdf/pd … 18160AJ-60.html

Fast Page Mode CMOS 1Mx16bit Dynamic RAM

That tells us all we need to know. This is a 16Mb chip, so 2MB. Four of those makes 8MB (and as it contains 4x16=64 datalines it's electrically double-sided as well as physically). These are about as bog-standard as you can get. Any other 4MB or 8MB 60ns FP SIM with 1Mx32 or 2Mx32 struture will work in any event. Probably your board will accept 16 and 32MB modules too, but we'd need more info for that.

But quite possibly you have a different problem. Duke Nukem will run happily with 2MB or RAM. What is the exact message you are getting? Possibly you don't have enough conventional memory, which is a configuration issue, not a shortage of actual memory...

I had all sorts of trouble on my first 486SX with 2MB. Lots of things would run, but not always and not every time. Not sure if I had DN at the time, but I did have Terminal Velocity and ROTT, both of which would sometimes crash and tell me to go get them more RAM. There's no reason to live like that anymore. 😉 FPM sticks can be had by the bucket load on eBay.

If upgrading, I suspect you can't mix single- and doublesided memory (electrically). I upgraded my 486DX2 back in the day, it had a single 8MB stick, and I added a 16MB. I don't remember if the total amount was shown as 20MB or it wouldn't run together and I removed the 8MB and put in a 4MB. But fact is - I ran 20MB total, making 4MB for a RAM drive. It totally rocked playing the demo version (one floppy) of DOOM from RAM drive .. 🤣

Thanks for the replies guys,

Just managed to haul my ass out of bed to crawl down to the computer for a quick photo shoot. This is the information I've managed to glean for the motherboard, DOS and Duke Nukem.

Result from DOS Mem command:

Fail message after running Duke Nukem:

Autoexec.bat (https://pastebin.com/MnXDkT0v):

Config.sys (https://pastebin.com/2yWLzenV):

Chipset (ALI M1429G A1):

Additional informat: There's only one out of a possible four 72pin 8mb ram stick installed. The static ram chips are W24257AK-15 and there are four installed out of a possible eight.

Remove the smartdrv line (Or put REM in front to comment it out) and try then. This is probably the one consuming 2MB of XMS.

While you do want smartdrv in general, then being that tight on RAM, for duke3d, you have a choice of having low speed access to HDD or not being able to run duke3d at all...

GigAHerZ wrote on 2020-02-25, 10:52:

Remove the smartdrv line

I'll give that a go thank you.

Do you know which ram sticks I could purchase that would best fit my set up?

EDIT: IT WORKS!

Any 72pin ram probably works. (There are EDO and FPM type memories, in general both work and i even have mixed them sometimes. Perf. difference is minimal)
Getting your machine to 32MB of RAM is a good place to be.

I've gone overkill with my Am486DX4-100 having 4x32MB EDO ram. 😜 Because not all of that can be cached by motherboard, i have 64MB (non-cached) ramdisk and other 64MB (cached) of ram is for the system itself to use.

GigAHerZ wrote on 2020-02-25, 11:20:

Getting your machine to 32MB of RAM is a good place to be.

Already on it 😉

Thanks for the advice, it's exactly what I needed.

Anthony

You can leave smartdrv, just limit it's memory use. Caching HDD it's wise to do.

lh c:\windows\smartdrv 128

This will use 128KB of extended memory.

cookertron wrote on 2020-02-25, 10:06:

Thanks for the replies guys, […]
Show full quote

Thanks for the replies guys,

Just managed to haul my ass out of bed to crawl down to the computer for a quick photo shoot. This is the information I've managed to glean for the motherboard, DOS and Duke Nukem.

[...]

Fail message after running Duke Nukem:486DukeNukemError.png

That's not Duke Nukem but Duke Nukem 3D. It has *slightly* higher requirements. It helps if you're specific...

GigAHerZ wrote on 2020-02-25, 11:20:

Any 72pin ram probably works. (There are EDO and FPM type memories, in general both work and i even have mixed them sometimes. Perf. difference is minimal)
Getting your machine to 32MB of RAM is a good place to be.

I've gone overkill with my Am486DX4-100 having 4x32MB EDO ram. 😜 Because not all of that can be cached by motherboard, i have 64MB (non-cached) ramdisk and other 64MB (cached) of ram is for the system itself to use.

EDO tolerance or support is very rare on 486 chipsets, actually working when mixing them even rarer... mixing only works with chipsets that tolerate EDO but don't support it. This board has a late ALi chipset that iirc has native EDO support. If so, mixing EDO and FP won't work. It's definitely not best practice. Nope, FP only.

OP has FP, upgrading with more FP will definitely work and is hardly any more difficuly or expensive than getting EDO. Just a second 8MB FP SIMM would be more than enough to run pretty much any DOS game and have some to spare for caching too.

dionb wrote on 2020-02-25, 16:10:

Nope, FP only.

Thanks for the reply.

So I'm guessing EDO ram isn't compatible with the ALI 1429G chipset? All the motherboards I've looked at with the 1429G state FPM.

If so Booooooo, I'll have to relist the sticks I just purchased.

Anthony

@cookertron, your board just might tolerate EDO ram enough so those would work without a problem. Best way to know - try it out, once you have those ram sticks in your hand. 😀

GigAHerZ wrote on 2020-02-26, 09:20:

Best way to know - try it out, once you have those ram sticks in your hand. 😀

You betcha bottom dollar I will!

Just got my SB16 today too... amazing!