Nice. Even though the 6x86 is considered a bit sucky, I have some fond memories of it (the original, not the L or MX versions) because for a time it was competitive with the Pentium. I still remember how badly I wanted a P200+. I don't know if the 6x86-P120+ is the best one to shoot for though. It uses a fairly gimpy 50MHz FSB. The P150+ (2x60) and P166+ (2x66) were the more popular models.
Recently I tracked down an original P200+ for my CPU collection (they're actually kind of rare), and I'm not sure if I want to use it or not because I don't want to ruin the silkscreen...but I am tempted to build a system around it with an M-tech Mustang R-534F/G with SiS 5571 chipset. That was the most recommended board for the original 6x86 for while because it supported the linear burst mode that made the 6x86 shine. What kind of board do you plan on using?

Well, i managed to make 4 additional partitions and i formatted them all. I installed dos 6.22 and windows 95 on the primary partition. I used also the starter pack installation from Phils lab (https://www.philscomputerlab.com/ms-dos-starter-pack.html) and generally i am ok. Today i am installing dos and windows games and most of them run great. My Roland MT32 also works great. Now, the following:

1. I have to change the cmos battery, i haven't opened my computer yet to check how it is. So every time i boot the computer, i have to press F1 to continue.
2. Regarding the sound card, i have the sound blaster vibra 16, it works great in Windows but in the dos there are some games and especially from Sierra On Line that although at the menus it seems that the games support it, when i run them a msg comes saying that cannot initiliaze the audio hardware. Do i have to do something to solve this? Is there a better sound card for dos compatibility?
3. I have done a little research regarding the ESS audiodrive ES1868 and ES688F. Are these cards good for dos gaming? Which is better from these two?
4. Sierra On Line adventure games run very well on Windows, but is there a way to use the Roland MT32 for the music instead the Windows sound? Roland MT32 is a lot better.

Thank you

Anonymous Coward wrote on 2019-12-27, 14:24:

Recently I tracked down an original P200+ for my CPU collection (they're actually kind of rare), and I'm not sure if I want to use it or not because I don't want to ruin the silkscreen...but I am tempted to build a system around it...

That's the same decision I faced when building my K5-PR200 system. I was very careful with the heatsink and didn't use any heatsink compound. The Cyrix 6x86-PR200 surely runs a lot hotter than the K5, so not sure if it will cope without heatsink compound. Perhaps instead of using the Cyrix branded PR200 you can use the IBM branded PR200; they aren't quite as rare.

Anonymous Coward wrote on 2019-12-27, 14:24:

M-tech Mustang R-534F/G with SiS 5571 chipset. That was the most recommended board for the original 6x86 for while because it supported the linear burst mode that made the 6x86 shine.

I remember testing the cx6x86 linear burst mode in at least one socket 7 board that supported it and didn't notice any performance benefit from it. The board had an enable/disable jumper so I could test both states. I don't recall if I checked the register setting to ensure it really was on/off though, so maybe it was always on or always off.

All of the original 6x86 chips ran hot, but the P200+ was particularly bad. Infact, initially it was quite difficult to build a P200+ system that was stable because it required:

-a board that supported 75MHz FSB
-a board with voltage regulators that could handle the extra current
-an extra large heatsink and fan. A standard Pentium heatsink wasn't enough

The last two points are what really killed the deal. It seems trivial today, but back then unless you were into electronics it wasn't an easy problem to deal with.
That's one of the reasons why the original P200+ was so rare, the other reason being low yields. Cyrix used a special fabrication process just for this model.
It was only on the market for a few months before being replaced with the 6x86L. But the 6x86L doesn't have the same appeal, because by that point Cyrix was basically already dead because they had nothing to compete against the PMMX or the PII.

Dimitris1980 wrote on 2019-12-29, 18:57:

1. I have to change the cmos battery, i haven't opened my computer yet to check how it is. So every time i boot the computer, i […]
Show full quote

1. I have to change the cmos battery, i haven't opened my computer yet to check how it is. So every time i boot the computer, i have to press F1 to continue.
2. Regarding the sound card, i have the sound blaster vibra 16, it works great in Windows but in the dos there are some games and especially from Sierra On Line that although at the menus it seems that the games support it, when i run them a msg comes saying that cannot initiliaze the audio hardware. Do i have to do something to solve this? Is there a better sound card for dos compatibility?
3. I have done a little research regarding the ESS audiodrive ES1868 and ES688F. Are these cards good for dos gaming? Which is better from these two?
4. Sierra On Line adventure games run very well on Windows, but is there a way to use the Roland MT32 for the music instead the Windows sound? Roland MT32 is a lot better.

1. Will depend on the system. Some are a simple coin cell battery you can buy anywhere, or you may have a barrel which you want to remove before it leaks. either should be easy to recognise though. 3rd possibility is a Dallas RTC google that if you can't see any battery on the motherboard. While the case is open make a note of the motherboard modal as well as that'll tell us what replacement options you have.

2. SoundBlaster 16 is a very compatible card. You will want to install the drivers though. As your familiar with Phils pages he has what you need on his pages you want the sbbasic.exe and maybe ctcmbbs.exe if its a PNP model. (check the CT number printed on the card)
https://www.philscomputerlab.com/creative-labs-drivers.html

3. ESS are good, better or worse then your SB16 is debatable. Personally I would stick with the SB16 for now as its the defacto standard so will be easyist to get up and running. Then when your up and running do some more research as you have many, many options for dos sound cards all with pro's and con's

4. Definitely! It's the whole reason of a MT32 I thought! In Device Manager, Multimedia, Midi you'll want to set your default device to External Midi port. Also in Device manager check what I/O address the MPU 401 port is using. usually 300 or 330. Some game setup programs will ask for this number.

Just a thought -- you're obviously fighting multiple problems at once here. Might help to knock them out one at a time, so you don't end up with bits and pieces of advice that send you off in a dozen directions.

Before you go buying any new sound cards or formatting anything, let's deal with the two easy issues: 😀

1. The battery. Chinny has you squared away there, but I'll add a second voice just to reiterate the take-aways. There are three types:
Coin cell: Easy! Just swap it out for a new one.
Barrel batteries: Basically like a short AA cell soldered to the board, probably leaking acid and ruining everything in its vicinity - you need to have basic soldering skills to replace it. At the very least, snip its legs off to avoid having your board corroded to bits.
Dallas Real-Time Clock (RTC) module: It looks like a fat chip probably in a socket. Look for the white silkscreen on the top. There's usually an alarm clock icon. These are still being made, so you can order a new one. The part number has changed slightly, and there were a couple of slightly less common variants. Let us know what you see.

2. The hard drive. Yes, FAT16 can only use a maximum of 2GB partitions. If you have a 20GB disk, that means dividing it up into 10 drive letters -- not so nice. With Win95 OSR2, you can use FAT32 instead. (The original retail Win95 didn't support it.)

I took this picture. Is this barrel black thing the battery? I have no access there. It is below the drives and their support plate and probably i have to dismantle them all. I have changed the dead pram battery on my Macintosh computers (LC475, Performa 6116, Powermac G3 Minitower) and it was so easy because the battery was in an obvious and easy spot.

No, that looks like a capacitor.

Your motherboard is the right age to have an RTC module with an integrated battery.

How do you change that?

There is VT82887 real time clock digchip

If your lucky and it's in a socket you can just replace it with a new one. If not all you have to do is desolder the old one and solder in a new one.

chrismeyer6 wrote on 2020-01-01, 14:33:

If your lucky and it's in a socket you can just replace it with a new one. If not all you have to do is desolder the old one and solder in a new one.

Or do the dallas rtc mod, it's not that hard and after that you can simply use a normal battery

Good catch I completely forgot about the mod.

From what I remember the original Cyrix chips had a 1x multiplier, that may not seem like much but I had a stack of pc100 motherboards back in the day.

A p120+ gets a bit lively on a 100mhz FSB

Not historically accurate but some of the old SIS motherboards would overclock to 90mhz

All this said FSB is why the p166+ was so popular since it kicked the pants off with its 66mhz x 2x = 133mhz

And yeah I did own a Cyrix P200+ System back in the day, it came out of the computer shopper with one of the more advanced PCCHIPS motherboards. Ran rock solid during my entire ownership. Oddly it was much more stable than my first k6-2 450mhz bought years later on one of those odd 90mhz FSB PCCHIPS boards
(that I could never get working with any other dimms other than what was included)

Dimitris1980 wrote on 2020-01-01, 11:55:

There is VT82887 real time clock digchip

Yup, that has an integrated lithium battery. As noted, you'll either have to replace it or alter it for an external voltage source.

How do you dismantle it?

you need to do some scrapping and soldering , here is how to do it:
https://www.classic-computers.org.nz/blog/200 … attery-chip.htm
http://purpleavenger.blogspot.com/2006/09/hac … 7-rtc-chip.html

there is also maeslin's replacement rtc that is free to make , looks like this: Re: DS12887 drop-in replacement

What is it better?

1) Fat32 with partitions

Or

2) Fat16 with partitions

I want to be able to run pure dos and in another partition to have Windows 95 installed. My hard drive as mentioned is 20gb, I would like to use at least 10gb even if I have to make various 2gb partitions. But can I use Fat32 and install ms dos 7.1 and Windows 95? Right now via fdisk I have made one 2gb partition for dos and one extended partition where I have Windows 95 installed.

If your using the included version of dos with Windows 95 you don’t need a partician or anything to boot to dos, just keep it all together