VOGONS

i387sx Mathematic Coprocessor

Topic actions

First post, by krivulak

Posted on 
User metadata
Rank Member
Rank
Member

Hi,
I am a proud owner of limited edition Siemens-Nixdorf PCD-3Gsx which were made for town hall in my town. It has 3 MB of RAM, Intel 386sx with clock not known to me (maybe 16 MHz?), onboard VGA, 120 MB WD Caviar 1210 and 3,5 FDD. Pretty bare minimum, but on the other hand, it was built in 1989. My dad bought it when I was newborn (1997) as used and it followed me my entire life. First games, first homework done on PC, all was done on this particular PC. When my mom decided that it is not sufficent anymore in 2004, she went to electronics store (Electro World, kind of mix of Radioshack and Walmart, if I compare it to US shops) and bought computer with Celeron D 352, 1GB RAM, 160GB HDD, Win XP. Again, really great-built PC, works to this day and my father uses it every evening for watching videos on Youtube. And the old one has moved to my grandma's home where it lives and runs every single day (grandma is playing Solitare on WFW3.11). Argh, rambling again.

Long story short. I don't want to change anything on that beloved S-N, but everytime I am booting it it throws on me "Co-processor not installed". And since the first time I read it I am wondering - what is the advantage of having one?
I started searching, found some generic N80387SX 25 MHz chips on ebay: http://www.ebay.com/itm/1pcs-N80387SX-25-N803 … agAAOSw2gxYnca3 and I wonder if it is usable. Well the price isn't the thing I am worrying about, I will not die from lost 5 dollars, but I really don't want to harm the PC. Rather than doing something harmful I will keep it like it was. Anyway, what I really want to ask is what is the purpose of math coprocessor and what is the profit of having one installed?

Reply 1 of 5, by kixs

Posted on 
User metadata
Rank l33t
Rank
l33t

Not very useful for your PC. Only a handful of apps would use it anyway (like Autocad 10,11... Falcon 3.0). But it wouldn't hurt to have one installed either.

Try to see if there is any option in the BIOS for disabling checking the presence of math co-processor.

Visit my AmiBay items for sale (updated: 2025-10-29). I also take requests 😉
https://www.amibay.com/members/kixs.977/#sales-threads

Reply 2 of 5, by krivulak

Posted on 
User metadata
Rank Member
Rank
Member

Well, it is not a post-stopping problem, just information line, so I don't care about showing actally. And in BIOS it is set on Not installed.

Reply 3 of 5, by Ampera

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie

FPU usage really exist with many games until true 3D rendering, when games like Quake would run like Usain Bolt if Usain Bolt didn't have any arms or legs.

A 386 of almost any sort can't really run many 3D games, and those that do run on it, don't really need to use a FPU to do much of anything.

However some operating systems, like DSL, might get grumpy that you don't have a FPU, and for 5 bucks, it won't hurt the feeling of nostalgia if you threw one in there.

Reply 4 of 5, by GPA

Posted on 
User metadata
Rank Newbie
Rank
Newbie

if you install FPU and 16Megs of RAM, you can run Quake on it! Runs great at approx 10 SFP (seconds per frame) on my DX-12. Should be even more fun on SX. Btw Quake 2 did not want to start timedemo on my DX-12, but did run on DX-33, but game itself ran, visually at 20-30 SPF, so could be something like 50 SPF on SX-16 I expect.

Reply 5 of 5, by krivulak

Posted on 
User metadata
Rank Member
Rank
Member

Teeheehee C:

I actually tried to run Doom on this PC, after many hours of transfering files on floppies and fiddling with PKZIP/RAR/ARJ, I managed to run it and I got 3 SPF (I really like that term 😁 ), so yeah... Well, if it won't do much for me then I don't care. I actually am trying to build other baby AT with true 386, but it is hard to find parts. And I will want the coprocessor installed there.

Go to top of page Go to top of page
Back to General Old Hardware
Close window
Close window