VOGONS


386DX40 build

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Reply 80 of 434, by retro games 100

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Regarding the crystal oscillator on the 386 mobo. Does anyone happen to know what pin size it is? I notice that the website amigakit sells both 8 and 14 pin 66MHz oscillators. I wonder if either of those would work?

http://amigakit.leamancomputing.com/catalog/p … products_id=167 (8 pin, 66MHz osci)
http://amigakit.leamancomputing.com/catalog/p … products_id=827 (14 pin, 66MHz osci)

Reply 81 of 434, by Old Thrashbarg

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If it looks square, use an "8-pin" and if it's rectangular, use the "14-pin". Most 386 boards I've ever seen have used the rectangular ones.

The pin size refers to the IC socket it fits into... they actually only use the outer 4 corner pins, but I guess that was just the easiest naming convention they could come up with.

Reply 82 of 434, by retro games 100

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Ah thanks! 😀 Looking at the mobo photo in DK's original post, I think the board's osci is the one about an inch north of the mobo's cache chips. The one with the plastic tie around it, and it looks rectangular. I will buy a 14 pin osci from this website! Thanks.

Edit: Oops. They either don't sell or stock the 66 mhz osci. They do stock a 14 pin 64 mhz osci. Will that be OK, I wonder?

Reply 83 of 434, by retro games 100

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I've found another website, who do stock 66 mhz 14 pin oscis. The webpage is here -

http://ly.rsdelivers.com/product/iqd/spxo0032 … 14/2262272.aspx (14 pin 66mhz oscillator)

It says that this osci is 5v. Is that voltage OK, for a 386 mobo? Thanks a lot for any further advice.

Reply 84 of 434, by Old Thrashbarg

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Yeah, 5V is pretty much standard for those things.

And I see no reason why a 64mhz crystal wouldn't work, it'd just give you a 32mhz CPU speed rather than 33.33mhz.

Reply 85 of 434, by DonutKing

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Here's a pic of the crystal:

nnquxx.jpg

Writing on top reads:
K O Y O
KCO-120S
80.000MHz
* 93 - 04

Pretty sure the last line is the date code. I thin kthe part number is KCO-120S

If you are squeamish, don't prod the beach rubble.

Reply 87 of 434, by DonutKing

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No there's nothing wrong with it, its just that this board doesn't have jumpers to set the CPU speed, instead you have to physically swap the crystal to change speeds. The CPU runs at half the crystal's frequency so to install a 25MHz CPU you'd need a 50MHz crystal.

I'm going to leave the 80MHz crystal in mine.

Reply 88 of 434, by Mau1wurf1977

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Ah that makes sense!

Hmm could you solder a "socket" onto the board? And just insert whatever crystal you want?

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Reply 89 of 434, by DonutKing

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It's socketed already, that's why there's a cable tie around it. You should be able to fit any 14-pin style crystal in there.

If you are squeamish, don't prod the beach rubble.

Reply 90 of 434, by Mau1wurf1977

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Oh! Well that's a piece of cake then 🤣

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Reply 91 of 434, by Tetrium

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So no jumpers for this board?

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Reply 92 of 434, by DonutKing

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Only to swap between 386 CPU and 486 daughterboard, and to set the ISA bus speed (7.2MHz async, or a divider from the crystal).

If you are squeamish, don't prod the beach rubble.

Reply 93 of 434, by Mau1wurf1977

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DonutKing wrote:

486 daughterboard

I think I'm getting old...

I read the whole thread but didn't see anything about a 486 daughterboard 😢

Reply 94 of 434, by DonutKing

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I don't think I've mentioned it 🤣

In the manual it says you can buy an MS-4901 daughter board, which I assume is just an ISA card with a 486 CPU and chipset on it. There are about 3 jumpers you need to set if you want to use the daughter board's CPU instead of the 386 on the motherboard.

I'm not sure where you'd find one of these MS-4901 boards though, I reckon they would be as rare as rocking horse poop

If you are squeamish, don't prod the beach rubble.

Reply 96 of 434, by retro games 100

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I've ordered a couple of 14 pin 5V oscillators; 66mhz and 50mhz. I got them from rs-online.com. They seem to have a global presence, and so perhaps other people can get them where they are located. I also ordered a 3x AA battery holder.

Hopefully, I can begin testing this 386 mobo in a couple of weeks time, when all this stuff arrives. I would like to see if I can get 3DBench to score all points between 1 and 16, by changing the oscis, and also changing the mobo's jumpers/BIOS settings.

Reply 97 of 434, by DonutKing

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Well I've been giving it a bit of a workout today 😀

2q3stuv.jpg

Been playing Wing Commander with the cache disabled. It seems perfect with only 1 craft on screen at once but as soon as you get a couple in the area it starts to get a bit jerky in close combat. Still perfectly playable though. I'll try with cache enabled.

I must say the MT32 makes this game sound a million times better. Most other games I've tried, various lucasarts/sierra adventure games and some microprose strategy games, sounded a bit better with an MT32 than a sound blaster, but the difference wasn't earth shattering. Wing Commander on a sound blaster sounds primitive in comparison to the MT32. There is a marked difference for the better with the MT32, other games I could take it or leave it but you're really missing out in WC with a sound blaster.

If you are squeamish, don't prod the beach rubble.

Reply 98 of 434, by Amigaz

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DonutKing wrote:

but you're really missing out in WC with a sound blaster.

Amen to that 😀

The 386DX 40mhz with cache will be a bit too fast if you run it with everything enables, a slow down util like atslo or something like that might reduce the speed to a perfect level

What joystick are you using on this picture? looks like it will be usable for a left handed retard like me 😁

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Reply 99 of 434, by Mau1wurf1977

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DonutKing wrote:

Well I've been giving it a bit of a workout today 😀

It seems perfect with only 1 craft on screen at once but as soon as you get a couple in the area it starts to get a bit jerky in close combat. Still perfectly playable though

Excellent!

Love the picture. Thanks for sharing!

Wing Commander is "all over the place" regarding speed.

Later levels you have dogfights with asteroids around and large enemy ships. However the slowdowns are not bad as they make the game easier. It's quite a hard game as it is 🤣

If you have a machine that's tuned for the "busy parts" then you will find the game too fast if there is just a single enemy.

Origin at it's best 🤣

retro games 100 wrote:

I've ordered a couple of 14 pin 5V oscillators; 66mhz and 50mhz. I got them from rs-online.com. They seem to have a global presence, and so perhaps other people can get them where they are located. I also ordered a 3x AA battery holder.

Excellent!