Its the parity bit thats making it 65
if you used non parity it would read 64

Davros wrote:

Its the parity bit thats making it 65
if you used non parity it would read 64

That could perhaps be right, but I didn't think parity memory would be recognized directly by the OS to begin with, and it still wouldn't explain why the other half isn't being used.

EDIT:
So I tried disabling parity checking to see if perhaps 128MB is the hard limit and the parity is causing issues, but that had no effect. Taking 1 stick out and just rolling with 96MB also did not help, I cycled through all the sticks too and none of them are blatantly bad or anything.

I suppose I could just solve all my problems with a not so crappy motherboard yeah?

I got W2K installed and it was painstakingly slow but I wanted to see if it behaved any differently or would show me anything of value in device manager. I've never seen such little hardware in device manager, nothing chipset related was shown and the display adapter section was entirely missing too! It seems like this SiS 471 chipset is just too low end to be of any value.

I tested some more, with just two 32MB sticks in Windows (switched to 98, more tolerable startup time) reports 64MB, add another stick and it says 65MB. I ordered some non parity memory to see if that will have any different results. The memory that was previously in the system was non parity but only a couple 16MB sticks, if I add the new stuff with the old stuff and it goes past 65 in an OS then I know the parity memory is causing issues for the system.

Do you actually need that much? 64MB is more than enough for a Pentium and an overkill for this system already. I think you could be equally happy with anything more than 16MB on DX2-66.

Yes, I could settle for 64MB, the problem is that the machine claims it can take 128, detects 128, therefore I want to get to the bottom of why 128 isn't working. Otherwise yes, the things I plan on doing with this machine will probably be perfectly fine with 16MB as you suggested.

Don't forget that 64mb is 65,536 bytes so that may be confusing you into thinking it is 65mb and not 64. The hard drive manufacturers, with the aid of the courts, screwed up the whole system when they decided that a mb was 1,000 bytes instead of the 1,024 that it always had been from the beginning of computing history. Then we ended up with new terms like kibibyte and mibibyte (which I refuse to use). LONG LIVE THE 1,024 BYTE MEGABYTE!

sliderider wrote:

Don't forget that 64mb is 65,536 bytes

No, that's 64kb

sliderider wrote:

LONG LIVE THE 1,024 BYTE MEGABYTE!

No, that's 1kb

sliderider wrote:

Don't forget that 64mb is 65,536 bytes so that may be confusing you into thinking it is 65mb and not 64.

Yes I understand the math, attached is a picture, it quite literally says 65MB with 128MB inserted. Every OS I've thrown at it says this, if I use just two sticks (64MB) it will say 64MB.

leileilol wrote:

No, that's 64kb […]
Show full quote

sliderider wrote:

Don't forget that 64mb is 65,536 bytes

No, that's 64kb

sliderider wrote:

LONG LIVE THE 1,024 BYTE MEGABYTE!

No, that's 1kb

Whatever. The old way of measuring memory is still best.

Is it considered a necro if its my own thread? I've finally gotten back to tinkering with this system some more. I had bought some cache chips on ebay to try to boost it to the full 512KB but they weren't detected at all it seems, at least I didn't break any of the original ones getting them out / putting them back in again...

I've settled for just using 64MB of ram, like others have said it'll still be plenty. I've decided to dual boot 6.22 / Win3x and 95 A. Yes I said A, I only have one 2.5GB hard drive, I can live with a ~350MB second partition instead of having FAT32, there isn't any USB, and the performance seems to go to hell once the Active Desktop of IE4+ is installed (which B/C try to do automatically after the OS installation is complete).

I've got a couple loose ends to wrap up though:
Floppy cable isn't long enough to plug the 3.5" as A and the 5.25" as B (BIOS doesn't let me boot from B) so I found one on amazon that might be retardedly long but should meet the needs (32 inch).

The Trident VGA card in here is pretty meh, 512KB I believe, best I could do in 3.1 is 800x600 with 16 color. If I tried 256 color the refresh rate was apparently no good for the LCD monitor and if I tried 1024x768 then the screen was just blank. I've looked around some and might buy a Speedstar 64 ISA, the pictures suggested it has the 2MB upgrade installed already. The other option was a Mach64 but that's $80, just felt overkill for a novelty project.

My current debate is whether or not to put the VLB slots to use. Is there any OMGEPIC reasons to drop a VLB super io card in? This listing here looks like it has some potential but I don't know if it would really provide any enhancement over the one it currently has. The case really only has space for 1 hard drive, 1 3.5", and 3 5.25" bays (using only 2) so the second IDE channel won't be of any benefit but I'm wondering if there are any major benefits of the extra bandwidth available.

And I guess I'm open to rants about how keeping the 66mhz DX2 is a dumb idea and I should drop something else in but I don't see any voltage settings so this board might not even support 3.3v processors unless they have their own built in VRM like an overdrive would. The manual certainly doesn't list anything higher and it looks like a newer revision of the board added the voltage jumpers. (so rant wisely, there may not really be any other options unless I go the overdrive route)

64mb is more than enough for a 486 rig, NT should run ok just for kicks but storage is a pain.

If you have vlb slots why use an Isa card? I never cared much for trident cards, they usually can do the job but there considered pretty low end. You can easily find a decent vlb video card in the 20 to 30 dollar range. The 66mhz 486 is an awsome, capable and iconic CPU. Its great for dos but if your going to be using it alot for windows I would consider the upgrade.

nforce4max wrote:

64mb is more than enough for a 486 rig, NT should run ok just for kicks but storage is a pain.

Yes, I have tried NT4 and 98 as well for kicks but I already have other machines that are running them competently so I decided to do 95 on this one.

soviet conscript wrote:

You can easily find a decent vlb video card in the 20 to 30 dollar range.

I checked ebay and had trouble finding anything that had enough information on them to deem decent, everything else was double your range.

I agree about trident cards, I'm sure a 1MB trident would get the job done but this one did even worse in 95 than in 3.1, I can get 640x480 with 256 color, but higher resolutions cause the refresh rate to change to something the LCD won't tolerate (which is strange... LCDs should really ignore the refresh rate).

The best options I had found on ebay were a VLB mach32, a speedstar 64 (back of its box suggested it outperformed the VLB mach32 specifically...) or a mach64 for $80 (and also only ISA), which is more money then I'd like to put into the machine.

I do appreciate the feedback though, I've been needing people to bounce ideas off of. It feels like these tinkering projects are less fulfilling if there isn't anyone to talk about them with.

While you can tweak a 486DX2 66 a little bit, it won't make a huge difference. Certainly not in the sense of getting things to run that simply don't run well on a 486.

I'd leave it as it is, save the money and put it towards another computer, or upgrade the mainboard with a Socket 7 board and Pentium CPU.

Mau1wurf1977 wrote:

While you can tweak a 486DX2 66 a little bit, it won't make a huge difference. Certainly not in the sense of getting things to run that simply don't run well on a 486.

I'd leave it as it is, save the money and put it towards another computer, or upgrade the mainboard with a Socket 7 board and Pentium CPU.

Yes I agree, see this is part of a collection, I have 386 and up, so I already do have a socket 7/233MMX which is quite a lovely machine once I discovered the strange USB header ("AT Style") and even a PS/2 header and found working cables for both.

I've been working my way down the line trying to bring out whatever potential each one has, this one has so far been somewhat of a letdown in that I really couldn't do much more for it other then boosting it to 64MB of ram and maybe getting a better graphics card.

I did have fun staring at motherboard diagrams online and googling bios ID strings until I could pinpoint just what this mobo was, they did such a terrible job branding these things back in the day. I guess the best thing I did for it was save it from the evil blue battery of death that was silently leaking away without me even knowing it was a threat.