It's trading memory speed for processor speed.
If the game you're running is CPU intensive, then the extra CPU speed will matter more.
On the other hand if it's doing a lot of memory or I/O thrashing, then the faster bus will be more meaningful.
It depends on the game you want to run.

Empirically though, there isn't too much difference between either in practice.

I'd get the 33Mhz osc anyway personally, and do some benchmarking to see which CPU works out better. For what it's worth, the DX2-66 is generally easier to work with than the DX-50, but both will require some cooling (a good heatsink, preferably with a fan too) as they can run pretty hot.

Eep386 wrote on 2021-06-02, 16:27:

It's trading memory speed for processor speed. If the game you're running is CPU intensive, then the extra CPU speed will matter […]
Show full quote

It's trading memory speed for processor speed.
If the game you're running is CPU intensive, then the extra CPU speed will matter more.
On the other hand if it's doing a lot of memory or I/O thrashing, then the faster bus will be more meaningful.
It depends on the game you want to run.

Empirically though, there isn't too much difference between either in practice.

I'd get the 33Mhz osc anyway personally, and do some benchmarking to see which CPU works out better. For what it's worth, the DX2-66 is generally easier to work with than the DX-50, but both will require some cooling (a good heatsink, preferably with a fan too) as they can run pretty hot.

After I install the 33mhz oscillator, will I be able to switch from the DX-2 to the Dx-50 without replacing oscillators again to do the tests you suggest?

andre_6 wrote on 2021-06-02, 16:38:

After I install the 33mhz oscillator, will I be able to switch from the DX-2 to the Dx-50 without replacing oscillators again to do the tests you suggest?

No, if you put back the DX-50 with the 33MHz oscillator you will effectively get a DX-33. The oscillator determines the bus frequency, and the bus frequency determines the CPU speed. It's just that a DX2 internally multiplies it by 2.

Can get confusing on some early 486 boards and 386 boards where they used a double speed oscillator to halve down for the frequency, i.e. 80Mhz for 40, 66Mhz for 33, 50Mhz for 25.

Well, you could leave the 33Mhz osc in to run your DX-50 at DX-33 speed. This would effectively be underclocking the part. One reason you might do this, is to get the chip to run (quite a bit) cooler, or to see if your game wouldn't be satisfied with a lower speed anyway.
The DX2 OTOH will see whatever osc you put in the board, and try to run at double its speed. eg. a 33 MHz osc becomes 66MHz to the CPU. With a 50MHz osc and a DX2, you'd get 100MHz, but as your part is only rated for 66MHz it will not likely work.

Might get a DX4 100 to run at DX2 100 on a board that's normally solid at 50. However, all of those apart from upgrade versions which may have multi nailed down, are 3.3V not 5V

andre_6 wrote on 2021-06-02, 14:38:

Right now I am looking for those little upgrades I can do to the build in order to close it for good. What would make the most difference for 2D and 3D DOS gaming: a Trident 8900 1MB ISA for example, the DX-2 (which would require buying the 33mhz crystal), or 16MB RAM? I can't find the specs anywhere to know if I need parity or non parity RAM, that still confuses me.

What I would like is to have a notion of what performance increase each of those upgrades would give me, to compare with the costs of buying them and see if it's really worth it. Thanks!

There is nothing in this world that will make an ISA bus 486 noticably faster in 3D unless you have an incredibly slow VGA card like the OTI crap, so you may as well just get more RAM for things like Windows for Workgroups 3.11. If you will buy an ISA graphics card buy one with good GUI acceleration and 1MB or more memory for higher resolution screen modes in Windows.

appiah4 wrote on 2021-06-03, 13:55:

andre_6 wrote on 2021-06-02, 14:38:

Right now I am looking for those little upgrades I can do to the build in order to close it for good. What would make the most difference for 2D and 3D DOS gaming: a Trident 8900 1MB ISA for example, the DX-2 (which would require buying the 33mhz crystal), or 16MB RAM? I can't find the specs anywhere to know if I need parity or non parity RAM, that still confuses me.

What I would like is to have a notion of what performance increase each of those upgrades would give me, to compare with the costs of buying them and see if it's really worth it. Thanks!

There is nothing in this world that will make an ISA bus 486 noticably faster in 3D unless you have an incredibly slow VGA card like the OTI crap, so you may as well just get more RAM for things like Windows for Workgroups 3.11. If you will buy an ISA graphics card buy one with good GUI acceleration and 1MB or more memory for higher resolution screen modes in Windows.

I have an OTI-077 1MB VGA installed, so it should one of the crap cards you mentioned haha

I am looking at a 1MB Trident 8900CL, looks more affordable. Bought 16mb RAM and the SRAM chip to fill the slot that was mentioned before, it was very cheap so why not:

Eep386 wrote on 2021-06-02, 14:59:

I'd vote the Trident 8900CL or 8900D (don't bother with the 8900B or 8900C, they're much slower). 16MB of RAM isn't strictly required (unless you plan on playing more complex games) but is quite nice to have, if you can find it cheap then by all means use it.

One relatively cheap upgrade you can do on your FIC board is populate the dirty TAG socket with a 32Kx8 15ns or 20ns SRAM. What this will do is enable write-back caching on the chipset, which *significantly* improves off-cache memory access speed, regardless of the CPU you use. In many cases you don't even have to fiddle with the jumpers either. You can look for another Toshiba TC55328P-20, Alliance AS7C256-20PC or -15PC, Winbond W24256AK-20 or -15, EtronTech EM51256C-15 or -20, or any 28-pin 32Kx8 SRAM rated at 20 or 15ns that will fit.

Dirty Tag.png

As for the 33mhz crystal I ordered it and will give it a try to choose between processors. I don't see more upgrades within my system's limits or reasoning that can be done, if you do I'm all ears. Looking forward to see the differences, I will verify them upgrade by upgrade to really see the true effect of each one

If you really want an upgrade just go for an MPU-401 intelligent mode MIDI card and a MIDI device. For those specs I'd go with an MT-32 first, then possibly a Sound Canvas or a Dreamblaster product. The difference you'll hear in game music will be way more significant than any abysmal 3D performance (or improvements thereof).

appiah4 wrote on 2021-06-03, 15:47:

If you really want an upgrade just go for an MPU-401 intelligent mode MIDI card and a MIDI device. For those specs I'd go with an MT-32 first, then possibly a Sound Canvas or a Dreamblaster product. The difference you'll hear in game music will be way more significant than any abysmal 3D performance (or improvements thereof).

I'll keep that in mind, in any case I'm looking forward to see the differences upgrade by upgrade. Truth be told I would be satisfied with it as it is and for what it is, but the upgrades you all suggested were perfectly affordable so why not. Will only get more expensive as time passes

appiah4 wrote on 2021-06-01, 06:19:

1. CTRL+X, CTRL+Q, CTCL+C; sometimes you just need CTRL+ALT+DEL as not all DOS games had this nice exit routine apparently. 2. T […]
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1. CTRL+X, CTRL+Q, CTCL+C; sometimes you just need CTRL+ALT+DEL as not all DOS games had this nice exit routine apparently.
2. There is probably a config file you copied over from a media where it was read only. Do a DIR /S /AR *.* in the game directory, and if there is a read only file do ATTRIB -R FILE.EXT
3. It can be wired and configured both ways. If you want it the other way then you will have to shift your turbo button connector to the left or right by one pin on the motherboard, then change the turbo display's segment jumpers around until it shows you what you want. It's going to be frustrating so just enjoy it as it is if you want my advice. You can do this when you get the 33MHz crystal and want 66/33 anyway if you really want it.
Enjoy your build. Always great to hear about something coming together and making a fellow VOGONer happy.

Also, I have been trying to correct the problem with registering the configurations for DOS games, in many games I get the error that I can't save the configurations, not just in one specific case, so I can't map the keys or sound. I also get the "not enough memory" messages in many games. I think that may be beyond my abilities, would you guys please take a moment to take a look at my config.sys and autoexec.bat so I can have a "good" configuration to keep? I have already made backups of the files:

What is the report you get when you type MEM at the DOS prompt?

You can try replacing certain device drivers with newer and more efficient ones.
One obvious candidate is MOUSE.EXE.
Hunt down CuteMouse / CTMOUSE and replace MOUSE.EXE with it, it will free up about 4-6K of conventional memory. It will also detect most serial and PS/2 mice more quickly than MOUSE.EXE does.

Perhaps you can also replace GSCDROM.SYS with VIDE-CDD.SYS (part of the Acer/Benq CD-ROM driver package, if I am not mistaken)? That will free up as much as 11K compared to the Oak CD-ROM driver that Microsoft tended to favor.

Eep386 wrote on 2021-06-05, 16:04:

What is the report you get when you type MEM at the DOS prompt? […]
Show full quote

What is the report you get when you type MEM at the DOS prompt?

You can try replacing certain device drivers with newer and more efficient ones.
One obvious candidate is MOUSE.EXE.
Hunt down CuteMouse / CTMOUSE and replace MOUSE.EXE with it, it will free up about 4-6K of conventional memory. It will also detect most serial and PS/2 mice more quickly than MOUSE.EXE does.

Perhaps you can also replace GSCDROM.SYS with VIDE-CDD.SYS (part of the Acer/Benq CD-ROM driver package, if I am not mistaken)? That will free up as much as 11K compared to the Oak CD-ROM driver that Microsoft tended to favor.

Sorry about the angle, had to stand up to block the sun, for now the pc is in a temporary spot. Stupid question, how do you replace drivers in DOS 6.22 / Win 3.1? Just erase them?

Yeah, you can replace their entries in AUTOEXEC.BAT or CONFIG.SYS, just by overwriting or deleting their mentions in those files.
If you'd rather temporarily "dummy out" an entry in AUTOEXEC.BAT, put REM in front of the entry:

REM C:\whatever\lol.exe

Another thing you can try for now, in AUTOEXEC.BAT, you can also try adding an LH in front of the statement that loads MOUSE.EXE, like so:

LH C:\MOUSE\mouse.exe /Q

That will force MOUSE.EXE to load into upper memory.

Actually you don't have enough upper memory free for that to work with the stock Microsoft mouse driver. Try replacing your mouse driver with CTMOUSE. Another nice thing about CTMOUSE is it will automatically load most of itself into upper memory if it is available, plus it chomps a lot less memory down in general.
Copy everything inside this ZIP file...
http://cutemouse.sourceforge.net/download/cutemouse21b4.zip
...to a floppy disk, and on your 486 copy the contents you just put on the floppy, to a convenient location on the hard drive.
Use MD C:\CTMOUSE to make such a convenient location. If you put everything on a "fresh" floppy with nothing else on it you can then type this to put all that stuff into the CTMOUSE directory:
COPY A:*.* C:\CTMOUSE

Once you have that installed, replace the entry for MOUSE.EXE with one pointing to where you installed CTMOUSE:

C:\CTMOUSE\ctmouse

Do something similar with VIDE-CDD.SYS, to replace the entry for GSCDROM.SYS in CONFIG.SYS. You can get VIDE-CDD.SYS from here:
http://vogonsdrivers.com/getfile.php?fileid=1456&menustate=0
Once you've got that copied over, change the entry for GSCDROM.SYS to opint to VIDE-CDD.SYS, eg.

DEVICEHIGH=C:\CDROM\VIDE-CDD.SYS /D:MSCD000

You don't need the /L=whatever switch, that was added by MemMaker and was more or less "customized" for GSCDROM.SYS. VIDE-CDD.SYS will be smaller so that switch as it were would likely not work the same anyway.

Eep386 wrote on 2021-06-05, 16:26:

Yeah, you can replace their entries in AUTOEXEC.BAT or CONFIG.SYS, just by overwriting or deleting their mentions in those files […]
Show full quote

Yeah, you can replace their entries in AUTOEXEC.BAT or CONFIG.SYS, just by overwriting or deleting their mentions in those files.
If you'd rather temporarily "dummy out" an entry in AUTOEXEC.BAT, put REM in front of the entry:

REM C:\whatever\lol.exe

Another thing you can try for now, in AUTOEXEC.BAT, you can also try adding an LH in front of the statement that loads MOUSE.EXE, like so:

LH C:\MOUSE\mouse.exe /Q

That will force MOUSE.EXE to load into upper memory.

Actually you don't have enough upper memory free for that to work with the stock Microsoft mouse driver. Try replacing your mouse driver with CTMOUSE. Another nice thing about CTMOUSE is it will automatically load most of itself into upper memory if it is available, plus it chomps a lot less memory down in general.
Copy everything inside this ZIP file...
http://cutemouse.sourceforge.net/download/cutemouse21b4.zip
...to a floppy disk, and on your 486 copy the contents you just put on the floppy, to a convenient location on the hard drive.
Use MD C:\CTMOUSE to make such a convenient location. If you put everything on a "fresh" floppy with nothing else on it you can then type this to put all that stuff into the CTMOUSE directory:
COPY A:*.* C:\CTMOUSE

Once you have that installed, replace the entry for MOUSE.EXE with one pointing to where you installed CTMOUSE:

C:\CTMOUSE\ctmouse

Do something similar with VIDE-CDD.SYS, to replace the entry for GSCDROM.SYS in CONFIG.SYS. You can get VIDE-CDD.SYS from here:
http://vogonsdrivers.com/getfile.php?fileid=1456&menustate=0
Once you've got that copied over, change the entry for GSCDROM.SYS to opint to VIDE-CDD.SYS, eg.

DEVICEHIGH=C:\CDROM\VIDE-CDD.SYS /D:MSCD000

You don't need the /L=whatever switch, that was added by MemMaker and was more or less "customized" for GSCDROM.SYS. VIDE-CDD.SYS will be smaller so that switch as it were would likely not work the same anyway.

Thanks, didn't free up enough memory, it's ok, I'll just play these particular games in another build

andre_6 wrote on 2021-06-05, 18:44:

Eep386 wrote on 2021-06-05, 16:26:

Yeah, you can replace their entries in AUTOEXEC.BAT or CONFIG.SYS, just by overwriting or deleting their mentions in those files […]
Show full quote

Yeah, you can replace their entries in AUTOEXEC.BAT or CONFIG.SYS, just by overwriting or deleting their mentions in those files.
If you'd rather temporarily "dummy out" an entry in AUTOEXEC.BAT, put REM in front of the entry:

REM C:\whatever\lol.exe

Another thing you can try for now, in AUTOEXEC.BAT, you can also try adding an LH in front of the statement that loads MOUSE.EXE, like so:

LH C:\MOUSE\mouse.exe /Q

That will force MOUSE.EXE to load into upper memory.

Actually you don't have enough upper memory free for that to work with the stock Microsoft mouse driver. Try replacing your mouse driver with CTMOUSE. Another nice thing about CTMOUSE is it will automatically load most of itself into upper memory if it is available, plus it chomps a lot less memory down in general.
Copy everything inside this ZIP file...
http://cutemouse.sourceforge.net/download/cutemouse21b4.zip
...to a floppy disk, and on your 486 copy the contents you just put on the floppy, to a convenient location on the hard drive.
Use MD C:\CTMOUSE to make such a convenient location. If you put everything on a "fresh" floppy with nothing else on it you can then type this to put all that stuff into the CTMOUSE directory:
COPY A:*.* C:\CTMOUSE

Once you have that installed, replace the entry for MOUSE.EXE with one pointing to where you installed CTMOUSE:

C:\CTMOUSE\ctmouse

Do something similar with VIDE-CDD.SYS, to replace the entry for GSCDROM.SYS in CONFIG.SYS. You can get VIDE-CDD.SYS from here:
http://vogonsdrivers.com/getfile.php?fileid=1456&menustate=0
Once you've got that copied over, change the entry for GSCDROM.SYS to opint to VIDE-CDD.SYS, eg.

DEVICEHIGH=C:\CDROM\VIDE-CDD.SYS /D:MSCD000

You don't need the /L=whatever switch, that was added by MemMaker and was more or less "customized" for GSCDROM.SYS. VIDE-CDD.SYS will be smaller so that switch as it were would likely not work the same anyway.

Thanks, didn't free up enough memory, it's ok, I'll just play these particular games in another build

Attach your autoexec and config files as a zip I’ll help you free up memory.

appiah4 wrote on 2021-06-06, 08:26:

andre_6 wrote on 2021-06-05, 18:44:

Eep386 wrote on 2021-06-05, 16:26:

Yeah, you can replace their entries in AUTOEXEC.BAT or CONFIG.SYS, just by overwriting or deleting their mentions in those files […]
Show full quote

Yeah, you can replace their entries in AUTOEXEC.BAT or CONFIG.SYS, just by overwriting or deleting their mentions in those files.
If you'd rather temporarily "dummy out" an entry in AUTOEXEC.BAT, put REM in front of the entry:

REM C:\whatever\lol.exe

Another thing you can try for now, in AUTOEXEC.BAT, you can also try adding an LH in front of the statement that loads MOUSE.EXE, like so:

LH C:\MOUSE\mouse.exe /Q

That will force MOUSE.EXE to load into upper memory.

Actually you don't have enough upper memory free for that to work with the stock Microsoft mouse driver. Try replacing your mouse driver with CTMOUSE. Another nice thing about CTMOUSE is it will automatically load most of itself into upper memory if it is available, plus it chomps a lot less memory down in general.
Copy everything inside this ZIP file...
http://cutemouse.sourceforge.net/download/cutemouse21b4.zip
...to a floppy disk, and on your 486 copy the contents you just put on the floppy, to a convenient location on the hard drive.
Use MD C:\CTMOUSE to make such a convenient location. If you put everything on a "fresh" floppy with nothing else on it you can then type this to put all that stuff into the CTMOUSE directory:
COPY A:*.* C:\CTMOUSE

Once you have that installed, replace the entry for MOUSE.EXE with one pointing to where you installed CTMOUSE:

C:\CTMOUSE\ctmouse

Do something similar with VIDE-CDD.SYS, to replace the entry for GSCDROM.SYS in CONFIG.SYS. You can get VIDE-CDD.SYS from here:
http://vogonsdrivers.com/getfile.php?fileid=1456&menustate=0
Once you've got that copied over, change the entry for GSCDROM.SYS to opint to VIDE-CDD.SYS, eg.

DEVICEHIGH=C:\CDROM\VIDE-CDD.SYS /D:MSCD000

You don't need the /L=whatever switch, that was added by MemMaker and was more or less "customized" for GSCDROM.SYS. VIDE-CDD.SYS will be smaller so that switch as it were would likely not work the same anyway.

Thanks, didn't free up enough memory, it's ok, I'll just play these particular games in another build

Attach your autoexec and config files as a zip I’ll help you free up memory.

Thank you so much for your time appiah4, along with other people you've been so helpful with all of this, very kind offer. I decided last night for many reasons to format and reinstall everything, the files are simpler, cutemouse is installed which should help. Whatever the lengths you can optimise them I'll be a happy camper

I have a last problem in need of solving, the monitor that came with the computer is in need of a heavy degaussing, and has the brightness getting higher and higher on its own until it comes back to "normal", only to restart in loop the same brightness process over and over. I think the monitor was probably in storage beside some speakers during all these years.

This is a monitor from 1992 so it only has a inner degaussing button, would I be able to open it only to activate the degaussing a few times to see if it works?I have tried with the usual magnet methods, it cleans up the image but it always comes back, and the brightness intensifying of its own only stops sometimes. Is it a job at my reach or am I setting myself up to get killed?

Eep386 wrote on 2021-06-02, 14:59:

I'd vote the Trident 8900CL or 8900D (don't bother with the 8900B or 8900C, they're much slower). 16MB of RAM isn't strictly required (unless you plan on playing more complex games) but is quite nice to have, if you can find it cheap then by all means use it.

One relatively cheap upgrade you can do on your FIC board is populate the dirty TAG socket with a 32Kx8 15ns or 20ns SRAM. What this will do is enable write-back caching on the chipset, which *significantly* improves off-cache memory access speed, regardless of the CPU you use. In many cases you don't even have to fiddle with the jumpers either. You can look for another Toshiba TC55328P-20, Alliance AS7C256-20PC or -15PC, Winbond W24256AK-20 or -15, EtronTech EM51256C-15 or -20, or any 28-pin 32Kx8 SRAM rated at 20 or 15ns that will fit.

Dirty Tag.png

I have the SRAM chip, but I'm confused with the board manual. With this 32kx8 20ns SRAM chip populating the free socket what is my total cache so I know how to change the jumpers?

The easy way to get the total cache is to watch the boot-up sequence. At some point it should say something like '256K CACHE ENABLED'. If it's an Award BIOS, then the cache will be listed on the final sign-on screen which shows the 'specifications' of the system.

For example, for 256K cache, both JS1 and JS2 should be set to 2-3.
If this is the case, just try putting the SRAM chip into that empty socket, aligned exactly the same way the other chips are (eg. if the text reads from left to right on the other chips, the chip you're adding should be aligned in the same manner).

If you've already installed the SRAM properly, then just power it up. Normally the BIOS won't say anything different about it, the difference will instead be measured in benchmarks and, in some cases, can be 'felt' as the system is generally running faster. On occasion you may have to enable L2 Write Back Cache in BIOS setup, but that's only on certain weird motherboards. (Sometimes that option is under a different name, such as "Tag includes Dirty" or "7+1".)

If you still have doubts about your cache size, or you are curious about the kind of performance you're getting, you can use a utility like CACHECHK to help you ascertain how much cache you have, and how fast your memory and cache access speeds are. (Run it without EMM386.EXE active, otherwise you'll get strange behavior.)

Ascertaining the cache size from CACHECHK is a little tricky at first as it won't outright tell you, but you can ascertain it by observing the access latency times.
Cached ranges will have a smaller "score" number than areas outside of cache, like so:

1             1    2    4    8   16   32   64   128   256   512   1024     etc..
2<meg range> 28   28   28   28   40   40   40    40    41    47    47....

From a listing like this, you can tell that accesses up to 8K are 28ns, so that would be the "first" level of cache in the system. On your garden variety 486 chip, it's usually up to 8K.
Accesses from 16K up to 256K are 40ns, so that would probably be your "second" level of cache. Sometimes the number at the very end of the "cached" range is a little higher or lower than the others, this is normal (some chipsets are like that).
Everything above 256K scores a higher number, so that would probably be the off-cache access speed.

I should mention that your results will undoubtably vary. Chipsets and memory configurations tend to vary very widely (pun not intended) from system to system.
In case you're curious as to what 'average' 486DX2-66 cache and off-cache scores should be, generally your L2 cache speed "scores" should be below 50 (around 47-ish) and your off-cache scores below 66.
For a DX-33, these numbers may be a little higher.

If CACHECHK gives you a warning about certain areas of memory being "really slow", don't worry too much about it, its algorithm for determining that kind of thing is a little buggy, and will often say that even if said ranges are blazing fast. Also, if certain cached ranges are really close to each other in speed, sometimes CACHECHK gets confused and says you only have one cache - you can disregard this message if, say, the L1 access is 28 and L2 access is something really close (but still discernably different) like 30 or 32, or other really close numbers. Certain *extremely* fast motherboards sometimes return scores like that.