VOGONS


First post, by renejr902

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I have several builds ( like 6 or 7 ) already from 486 to Pentium III. But now i want a 386.

Right now i use a lot my P2 266mhz because i can change fsb and multiplier to get it working at 133mhz. With setemul its the only build i got 2.51 in speedsys , so its my only system that can run at speed of 386 sx 16 to 20mhz or we can say 286 at 16 mhz. So i can play some 8088 and 286 games at acceptable speed, but a little too fast sometime.
But i can still use Slowdown utilities from Bret Johnson and use this parameter: slowdown /xt and i got a Ibm xt 8088 4.77mhz speed. With this utility some games froze like Moon Patrol, but Frogger 1 and 2, a old pinball, patrooper and much more games play near perfect speed like a 8088. Frogger 1 play with a few slowdown or too fast a little, instable speed, but frogger 2 is 100% like a 8088 to me. At least without slowdown utility but using setemul only and my 2.51 speedsys speed somes 8088 and 286 games play perfect like paratrooper and moon patrol is very playable just a little too fast, but playable. Frogger 2 is just a little too fast , but frogger 1 is really too fast to be playable.

So if i get a 386 sx 16 or 20mhz i can play Moon Patrol with it and some others 8088 and 286 games. But i cant really play Jazz Jackrabbit, its not fast enough for me, not with a 386 sx 16 by my memory or with setmul at 2.51 speedsys speed.

But with a 386 DX, for example at 25mhz, moon patrol is too fast to be playable, but Jazz Jackrabbit play good enough.

I know nothing is perfect. I play a lot of 8088 and 286 games from my childhood from 1982-1990 but im not interested to buy a 8088 or 8086 anymore. i had both a 8088 and a 8086 when i had 8-12 years old. I never had a 286 , only playing on my cousin 286 computer, so im not sure i want a 286. If possible i would like to play a lot of 8088 and 286 games and some 386 games like Jazz jackrabbit at acceptable speed with this build.

Questions: ( Read below before answering thanks)

1. What should i do. Buying a 386sx 16 or 20 or a 386 dx 20-25-33 ? I only like intel cpu, i dont want amd or cyrix for this build at least. i have a 100$ canadian deal for a epson equity 386 sx20 motherboard with all necessary accesories. But i hesitate to wait for a 386 dx. I dont know much things about a 286 , i only know stuff about 8088 and 8086. But i only want a vga monitor and im not sure a 286 can use a vga video card and vga monitor in a great way. And i think a 286 cant run any 32bit games like Jazz. or even doom. By the way at 14 years old i beat doom with a 386 dx-20 LoL! so for me doom on a 386 dx-33 is still playable today and Jazz is good enough on a 386 dx-20 or better at dx-25.( i compare them by my memories or by setemul test done recently. my 486 dx-75 can run at 386 dx-33 speed more like 37-38mhz i think, i dont remember my speedsys score anymore.)( i can have a Tandy 1000sx for 200$ canadian, but i dont think i want it, its a 8088, but i have a 8088 and 8086 for so much years when i was young, i dont miss them much, except for games.)

2. I know 386 sx have soldered cpu so i cant change it. But if i buy a 386 motherboard for 386 dx cpu. Could i change and switch the cpu for a dx-20 or dx-33 depending if i play Moon Patrol or Jazz ?Does all 386 dx motherboard that can accept any intel dx cpu like a dx-20 or dx-25 or dx-33 ? (or even any amd dx cpu ?)

3. Can i use setemul or slowdown or throttle with a 386 computer ? ( dx or sx)

4. Any recommandation.

5. Does all 386 sx or dx motherboard that can accept one of my 500 megs ide hard disk ?

6. I know that 8088 games exist. I can say the same thing for 386. But does exist games that target 286? if yes, which ones for example? Do all they work at correct speed on 386 ? or they can be too fast for a 386 ? Thanks

Thanks for advices and opinions.

( Note: I have corrected the spelling and grammar of my topic, but thanks for understand that my english is my 2nd language)

Reply 1 of 17, by cyclone3d

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Much easier to just change the clock crystal and if you changed the CPU, you would have told also change th clock crystal anyway.

If you want a speed changeable 386, then get a 386 Dx-40, some clock crystals for the different speeds you want, wire up an array on a proto board and then wire it up so you have switches or jumpers the quickly change between speeds.

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Reply 2 of 17, by renejr902

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cyclone3d wrote on 2020-10-13, 02:56:

Much easier to just change the clock crystal and if you changed the CPU, you would have told also change th clock crystal anyway.

If you want a speed changeable 386, then get a 386 Dx-40, some clock crystals for the different speeds you want, wire up an array on a proto board and then wire it up so you have switches or jumpers the quickly change between speeds.

Thanks for answer. It seems a good idea. I read on this forum some topics that talk about clock crystal oscillator. But honestly i dont know nothing about this. I just begin to read a text about this 5 minutes ago. Im not sure to get it at all. Do you have any links to help me to understand. or if you can explain me where to find that clock crystal oscillator or how to change it ? ( my father is a electronic technician if it can help.) Thanks a lot!

Reply 3 of 17, by renejr902

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Ok i just read some vogons topics about it. I think i got it. Thanks. But if you still have links to that stuff, let me know. Thanks.

So i just learned that all 386 cpu have a specific speed in mhz. So a 386 motherboard with a dx-33 cpu will still try to run at 33mhz with a dx-25 cpu ? isnt right ? thanks for answer. ( So i need to change the crystal oscillator, so i can skip changing the cpu anyway and only changing the crystal oscillator, in most cases, right? )

So finally, i will buy a intel dx-33 and do the oscillators mod with switch or jumpers at differents speed. I will try to get the dx-33 runs at 40,20,16,8,5mhz.. with differents crystal oscillators. Thanks again.

Reply 4 of 17, by cyclone3d

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I don't actually have any links. It should be pretty straightforward to build a crystal switcher though.

Looking at a datasheet, it looks like you could just wire everything up on a proto board and then have a single jumper block to switch between the crystal oscillators.

Pin 3 is the output and that is all you would need to switch between. There are also two grounds and a +5v to power it. Guessing it wouldn't matter if all the grounds were hooked together and all of them were powered at the same time.... though it might be better to have two jumper blocks to switch between power for the different crystals.

You could also use a dual rotary switch to switch between the crystals. Maybe mount the switch to the front of the case for some added wow factor.

Would be simpler to switch as well... just not while the computer is powered on. Probably wouldn't hurt anything but the computer would probably just hard lock... I think.

Yamaha modified setupds and drivers
Yamaha XG repository
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Aopen AW744L II SB-LINK

Reply 5 of 17, by renejr902

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cyclone3d wrote on 2020-10-13, 04:35:
I don't actually have any links. It should be pretty straightforward to build a crystal switcher though. […]
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I don't actually have any links. It should be pretty straightforward to build a crystal switcher though.

Looking at a datasheet, it looks like you could just wire everything up on a proto board and then have a single jumper block to switch between the crystal oscillators.

Pin 3 is the output and that is all you would need to switch between. There are also two grounds and a +5v to power it. Guessing it wouldn't matter if all the grounds were hooked together and all of them were powered at the same time.... though it might be better to have two jumper blocks to switch between power for the different crystals.

You could also use a dual rotary switch to switch between the crystals. Maybe mount the switch to the front of the case for some added wow factor.

Would be simpler to switch as well... just not while the computer is powered on. Probably wouldn't hurt anything but the computer would probably just hard lock... I think.

Thanks for all these informations, its really appreciated. I would do something special and maybe post it 😀

I can have a 386 motherboard with a intel dx-33 cpu for a good price but, is it a big problem if it has no cpu cache ? Thanks for answer.

( Would it affect games like Jazz, doom or older dos games ? )

( it seems to exist a very rare 32bit slot card cache for this motherboard but it cant be found anywhere now)

Reply 6 of 17, by renejr902

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I could be interested in this board too. I see no keyboard connector. But it seems a
" keyboard " label is written with a 4 pins connector. How can i connect a keyboard with a 4 pins. i cant find any pinout for this. i dont know if its a ps/2 keyboard or AT standard keyboard connector. Thanks for help or answer.

( edit: Do you see any cpu cache memory on the motherboard ? thanks )

(edit2: Please let me know if your find the motherboard brand and model or the computer model. I cant find anything. thanks )

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Reply 7 of 17, by waterbeesje

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Full AT megasized!!! Just count the number of components on there!

This is a very early board, clearly. The lack of cache is made up more than twice by the coolness factor 😁

This is not a McLaren, but more like a Mercedes. Not too fast, but clearly beautifully designed and build with care.

Ok, back to your situation:

This board is an early evolution of the 286 age, when a 386 was unobtanium. Cache was never heard of, so no sockets for it.
You may forget Jazz with this one in afraid, or play at pretty low framerates... but for less demanding stuff it would be great!
This one seems to have onboard fdd and HDD controllers so that wouldn't require an extra ISA adapter.
Support for any <500MB drive should exist, but with these early 386 boards there is a possibility it only supports standard AT drives, type 1-46 you may recall. Most bioses from 386 boards allow for type 47 and let you configure your own drive parameters, but when the 286 was mainstream, it wasn't yet that common.

Stuck at 10MHz...

Reply 8 of 17, by pentiumspeed

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This is Compuadd board, has cache. That red connector 4 pin is for keyboard, Find ground, and 5v then pick which is which are for clock and data pin then make adapter.
Disable all the i/o and use multi-i/o serial and parallel card instead.

Cheers,

Great Northern aka Canada.

Reply 10 of 17, by renejr902

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maxtherabbit wrote on 2020-10-13, 15:57:
pentiumspeed wrote on 2020-10-13, 15:34:

Disable all the i/o and use multi-i/o serial and parallel card instead.

Why is something wrong with it?

pentiumspeed wrote on 2020-10-13, 15:34:

This is Compuadd board, has cache. That red connector 4 pin is for keyboard, Find ground, and 5v then pick which is which are for clock and data pin then make adapter.
Disable all the i/o and use multi-i/o serial and parallel card instead.

Cheers,

waterbeesje wrote on 2020-10-13, 11:31:
Full AT megasized!!! Just count the number of components on there! […]
Show full quote

Full AT megasized!!! Just count the number of components on there!

This is a very early board, clearly. The lack of cache is made up more than twice by the coolness factor 😁

This is not a McLaren, but more like a Mercedes. Not too fast, but clearly beautifully designed and build with care.

Ok, back to your situation:

This board is an early evolution of the 286 age, when a 386 was unobtanium. Cache was never heard of, so no sockets for it.
You may forget Jazz with this one in afraid, or play at pretty low framerates... but for less demanding stuff it would be great!
This one seems to have onboard fdd and HDD controllers so that wouldn't require an extra ISA adapter.
Support for any <500MB drive should exist, but with these early 386 boards there is a possibility it only supports standard AT drives, type 1-46 you may recall. Most bioses from 386 boards allow for type 47 and let you configure your own drive parameters, but when the 286 was mainstream, it wasn't yet that common.

Thanks for answers guys! So much appreciated! I hesitate for another one, check uploaded pictures.
Tell me which you prefer. Thanks.

IMPORTANT Question, Thanks: I'm a little confuse. about that Compuadd motherboard, Pentiumspeed said it has cache. Waterbee said no cache. So does it has cache ? if yes where are the chips ? how many kb ram cache ? thanks

I think this Compuadd motherboard is in this topic with picture:

A couple (or, perhaps, quite a bit more) rigs for all ages

And how much % speed can lost a 386 with no cache ? How will be affect in % ? ( i already know for 486 and pentium, but for a 386 dx i have no idea how much faster it could be with cpu cache. Thanks)

My pictures just uploaded are from this one i think:

https://stason.org/TULARC/pc/motherboards/G/G … 6-GA-386PS.html

http://www.dosdays.co.uk/topics/Manufacturers/gigabyte.php

This one too has no cache. The cache memory card is too much rare.

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Reply 11 of 17, by cyclone3d

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The slot on that board is not for a cache board as far as I am aware. It is to add extra RAM via a full length ISA plus the special 32-bit slot.

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Reply 12 of 17, by renejr902

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cyclone3d wrote on 2020-10-13, 18:19:

The slot on that board is not for a cache board as far as I am aware. It is to add extra RAM via a full length ISA plus the special 32-bit slot.

ok thanks a lot!

But about my previous post with pictures. The Compuadd motherboard. ( the mega size board with red connector )

Waterbee told me that it has no cache.

Pentiumspeed told me it has cache.

I'm confuse. Thanks for help and answer.
I'm very interested at the compadd board, but i want cpu cache. If it has cache, please tell me how much cache kb does it have. Thanks

Can you tell me your opinion about the 386 cpu cache importance ? ( % in speed that can affect)

I think this Compuadd motherboard is in this topic with picture:

A couple (or, perhaps, quite a bit more) rigs for all ages

Reply 13 of 17, by renejr902

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Its the ebay auction if it can help. The item description talked about a 512kb simm memory x2. is it cpu cache ? i asked him questions, but he didnt know computer stuff at all he told me.

https://www.ebay.ca/itm/AMI-BIOS-Motherboard- … 353.m1438.l2649

Reply 14 of 17, by waterbeesje

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renejr902 wrote on 2020-10-13, 18:28:
cyclone3d wrote on 2020-10-13, 18:19:

The slot on that board is not for a cache board as far as I am aware. It is to add extra RAM via a full length ISA plus the special 32-bit slot.

Waterbee told me that it has no cache.

Pentiumspeed told me it has cache.

Now I'm confused too.
Looking at the boards pictures I didn't find any dip chips that looked like sram to me.
Please point then out of I'm wrong here ...

Stuck at 10MHz...

Reply 16 of 17, by debs3759

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I see there are a lot of 74F573D, which are Latches / Flip Flops. Not sure whether they are used as cache or not.

See my graphics card database at www.gpuzoo.com
Constantly being worked on. Feel free to message me with any corrections or details of cards you would like me to research and add.

Reply 17 of 17, by pentiumspeed

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The compuadd large motherboard does have pair of cache chips (52pin square ICs). You can use 1MB x 30 pin parity modules in 16 pieces to make 16MB total max.
Also the compuadd has nonstandard i/o interface that needs passive port panel plugged into this. Since we do not have pinout of this, Only way best way is disable all the parallel and serial port and use serial and parallel port isa card.

I had bare compuadd motherboard exactly like this once.

Cheers,

Great Northern aka Canada.