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tel: +1-602-945-8188 - select option 4
You may be interested to know that CAD-UL has integratedall the 386EX special peripheral registers into its bit field editorwithin the symbolic debugger.Of course the debugger works with CAD-UL's highly optimized PC nativeand 386EX cross cross compilers, however, did you know CAD-UL's debuggerswork nicely with the Borland, Microsoft, Watcom, and GNU compilers?

Mailing list

(This is a discussion forum via email...)

See here.


Several interesting emails about embedding a 386 processor.

Other sites At Intersil

Interesting mails

Date:    19980105
From:    Hegtor Mercure
To: <> 
Subject: Re: 386ex list activity

I was just wondering if this list is still active, I haven't heard much for ages. Has it moved, or is there another list somewhere else that I should know about?
Perhaps it just means that the life-cycle of 386ex is over ? It is like that just as you master these chips, they are suddenly outdated and go foranother rat-race learning the next one, and hope you can design something useful actually between the races.
And then you think yourself, why on earth did I not go to medical school, or started selling cars or something else ...

More Like embedded develpers have discovered the folly of designing in PC (Read Quickly Obsolete) Components into Embedded Systems. When was the 386 last used as a serious PC Processor anyway? Wasnt it 1988? 10 Years and still goin strong.
Sorry about that, im just cynical.

Date:    19980105
From:    David S Boud <>
Subject: Re[2]: 386ex list activity

This list is still active but the activity has decreased substantially since the product was introduced. I hope that is because Intel has enhanced the web presence substantially and that most designers are able to get the information they need. It is still a substantial phone support call generator but that has declined somewhat too. There are no plans at this time to end of life this product and sales are still steady. As for designing in PC components, the components taken over by Intel's embedded divisions will be around as long as sales are good. In the case of the microcontrollers, many have been around since the early eighties and are still being produced and marketed. The 386 you mention is still being produced and sold in several flavors most popular with embedded designers. The longevity of Intel's embedded products depend on the consumer of these products. If consumer interest ebbs and it is no longer profitable to produce the product any company would be foolish to continue producing it.

David Boud
Sr. Product Support Engineer
Intel Customer Support
(800) 628-8686

Date 19980119
From Bruce Ableidinger <>
Subject RE: High integration processors

Recently, there has been discussion here about follow-on 386EX processors and possible 486EX integrated processors from Intel. It is common knowledge that Intel is not pursuing new 386 or 486 embedded devices. Their embedded solution is to provide Pentium processors (most likely laptop mobile modules) and separate chipsets (like their recent automotive announcement). I doubt if the current Slot 1 P-II "bricks" will win over may embedded designs.

Date:    19960124
From:    Detlef Zuendorf <>
Subject: 386EX CPU module on PC/104 form faktor

We would like to promote our PC/104 card sized 386EX board to the audience. Shipping since August 1995 it has been used in a lot of different embedded system designs, where it gets used to provide a software compatible PC-Environment.

Here are some features of the 386EX, which can be included directly into your product:

Support available for:

Please feel free to eMail us at to get more information or the adress of the adress of the distributor nearest you.

Best regards,
Detlef Zuendorf
E-mail von: Sunrise Systems GmbH, 24-Jan-1996


A new Intel386(tm) EX evaluation platform, named the EXPLR2 board, is now available for OEMs to help design POS terminals, industrial control, medical instrumentation and other embedded PC applications. The EXPLR2 board will enable designers to test several new technologies on one board, thus saving time and money. Several key features on the EXPLR2 board include: Intel386 EX processor; Intel Flash memory; the RadiSys R380EX companion chip; the QNX real-time operating system; and Phoenix Technologies' system-enabling software.

Date:    19960820
From:    David S Boud <>
Subject: Notice: C-Step conversion ramp

To All Intel386(TM) EX Embedded Microprocessor Users:

Please remember that the A and B steps are nearing the end of their production cycles. The C-step is now in full production and has many fewer errata, improved AC timings, several enhancements and is higher speed. The A and B will be produced for only two more months then will be available as supplies last at the various distributor warehouses and you will need to have your orders in by October 15th. There is a C-Step conversion document available from customer support upon request. It will help those of you who need to convert. Just call your Intel service center and request it. In the U.S and Canada that number is (800) 628-8686. Outside this range please check with your local distributor or submit the request through the Worldwide Web at:

The document title is, "Intel386(TM) EX Microprocessor A-0/B-1 to C-1 Step Final Conversion Notification" and it is Conversion #147. A copy is available to your local distributor on his Notes Tech Docs database.

David Boud
Senior Application Support Engineer
Embedded Intel Architecture Specialist

Date:         19961112
From:         Corwin Nichols <>
Organization: MicroTech Conversion Systems
Subject:      386EX vs NS486 vs SC400 vs ???

I am designing a new embedded project having just completing one with the Intel 386EX. I know the EX pretty well right now. I have years of experience with Intel x86 processors and have a real time kernel which is known entity on x86 devices. It could port to some other processor I suppose, but my tool set would have to change ...

I started my new design with the EX in mind, but I find the EX is wanting for the necessary peripherals. I started out supplimenting the EX with a FPGA, adding a DMA* multiplexor, DRAM i/f, and misc. I/O support logic. Then I got the AMD announcement for their 'H2' (Elan SC400) which got me looking around. Now it seems like the National NS486SXF might be a better fit for my design. Basically I need four DMA* channels, support for flash ROM and 8 MB of dram. Three SIO* channels an IDE i/f, and quite a few parallel bits. The biggest failing of the SXF for me is the lack of a JTAG* port, but I may be able to work around that.

What I'd like to know, do any of you fine readers out there have any particular comments about the National or AMD parts?

Corwin Nichols - MicroTech Conversion Systems

Date:    19961112
Subject: Re: 386EX vs NS486 vs SC400 vs ???

I am very far along with a design using the National 486SXF. (will have a board to test soon, software dribbling in slowly)

I think the National chip is far superior to the Intel 386EX, but have been worried about the fact that i is new and perhaps hard to get hold of (though I have bought a few). AMD told me that their embedded 386 is cancelled, and the ELAN chips don't really fit most needs.

In conclusion (lacking real experience) I think the National chip is by far the best choice when you have the choice. The big issue for us was that it is PROTECTED MODE ONLY.

I also anticipate a cost-reduced version (486SXL?) that should be even more suitable for most projects.

Dan Falkoff

Date:    19961112
From:    Mark Morneault <>
Subject: Re: 386EX vs NS486 vs SC400 vs ???

On 19961112 you wrote:

I am very far along with a design using the National 486SXF. (will have a board to test soon, software dribbling in slowly)

I think the National chip is far superior to the Intel 386EX, but have been worried about the fact that i is new and perhaps hard to get hold of (though I have bought a few). AMD told me that their embedded 386 is cancelled, and the ELAN chips don't really fit most needs.

Not sure where or who you heard this from, but it is not true. The ElanSC300 and ElanSC310 are both in production and will continue to be in production. The ElanSC400 is not a replacement for either of those parts. As for your claim that the Elan chips don't fit most needs, can you qualify this or is it just *your needs* that it doesn't fit?

In conclusion (lacking real experience) I think the National chip is by far the best choice when you have the choice. The big issue for us was that it is PROTECTED MODE ONLY.

I'm glad you put the qualifier "lacking real experience" in your recommendation. Let's hear from someone who has evaluated both the National part and the new AMD ElanSC400 (which by the way IS a PC/AT compatible 486 embedded microcontroller).

Date:    19961112
From:    Jon Weisberg <>
Subject: RE: 386EX vs NS486 vs SC400 vs ???

Mark Morneault at wrote:

The ElanSC300 and ElanSC310 are both in production and will continue to be in production.

The rumor going around has been that the SC400 will replace the SC300/SC310 and that once large volume demand disappears - these parts will disappear. Has AMD made an official commitment to these parts, and for how long?

Also, do you know when will we see an extended temperature range version of the SC400?

Date:    19961016
From: (David E. Brown)
To:      386EX mailing list submissions <>
Subject: 386EX with 80387

Now that we've got our 80386ex system ready for production, we learn that the N80387SL cannot be purchased. Even though the July 1996 Users Manual for the EXTB and EXTC tells us how we might connect to a math coprocessor, it seems to be printed for the academically oriented. The last buy announcement might have been in April. The last buy for the 387SX might be Jan 97.

Does anyone have any alternate approaches (other than software emulation) ? Is there an alternate vendor ? I think ITT, Cyrix are no longer sources, but I'm not sure. I don't think a search through Computer Shopper is an appropriate solution for an OEM.

Lastly, am I the only person that thought the 80387 plus the 80386EX was an excellent combination?

Dave Brown
Pixel Performance
Simsbury, Connecticut

Date:    19961017
From:    Bohdan "Zeke" Tashchuk
To:      386EX mailing list submissions <>
Subject: RE: 386EX with 80387

Sorry I can't help you offhand about getting a 387. But I'm surprised that SOMEONE isn't making the 387. That's very useful information for the mailing list.

Lastly, am I the only person that thought the 80387 plus the 80386EX was an excellent combination?

The situation, as I see it, is that your requirements are in between the capabilities of a 386 without FP and a 486 with FP. How big of a market niche is that? It's a rhetorical question, I don't think anyone really knows. But RadiSys, for example, might argue that some solution points (from us anyway) in order of performance would be:

  1. 386EX with R380EX
  2. 486SX with R400EX
  3. 486DX with R400EX

What you want is between #1 and #3 in performance. So, how close is #2? Depending on the cost of a 387 (if you could buy one) what you want may or may not be cheaper than #2. Considering that the 486SX has an 8K internal cache and the 386EX has NO cache, a 486SX might well be fast enough at emulated FP for your needs.

But, in the spectrum of available embedded solutions that starts at 4-bit and 8-bit micros and goes all the way up to the fastest Pentiums, just how big a market niche is one you want? Look at it from the Intel embedded group's point of view. They have:

All of the preceding available in various variants, speed grades, and packages. Plus I'm sure there are many more I haven't listed. Some products will just have to fall below the cut line.

I know this isn't very good to hear, since you've already done your design with a 386EX. But if you NEED faster FP and you can't buy a 387SX, what are your alternatives? Other than (perish the thought) not being x86 compatible. I'd suggest that you take advantage of the last time buy to "buy" some time while you redesign.

Disclaimer: the preceding is solely my speculation and comments. I'm not in marketing at RadiSys, I'm not an official spokesman for RadiSys, and Intel doesn't keep me informed of what they're doing.


Date:    19960913
From:    Mikey Imel <>
To:      386EX mailing list submissions <>
Subject: RE: IO* R/W (ISA bus) in 386EX

I had used the 386EX for a special design recently,there is a ISA BUS LAN CHIP in my product, I just need a simple I/O read/write function, the hardware pin from the LAN chip is as follows:

But there is no ISA BUS signals in 386EX, would you have any suggestion for me !! Thank you !!

Richard Chen SEP 13, 1996 Taiwan

You are correct in that the 386EX uses a 386SX-like bus interface instead of the lower performance ISA bus interface; however, some of the "ISA BUS" signals can be directly hooked into the 386EX. In particular, most of the ISA bus interrupt pins hook directly into 386EX; however, you won't be able to hook to the 386EX's internal IRQ10 pin because this is one of the few interrupt pins thatIntel did not bring to the package interface.

You can, however, hook directly to IRQ1,IRQ3-9,IRQ12 or IRQ13 (but not both at once due to a pin multiplexing constraint), and IRQ14 without using an external interrupt controller. If you don't have control of the software (or there are many different OS/application programs that access the LAN chip require the use of IRQ10) and can't switch to another interrupt line you will have to seek an alternate solution.

You can use an inexpensive PAL* to convert the 386EX bus control signals to the control signals described above; however, if you also need DRAM control, IDE drive, flash support, keyboard controller and RTC support, you'll find that the R300EX part that we (RadiSys) supply will result in a cheaper, robust, and more integrated design. If you are interested, you can find the literature on our parts on the web at

Hope this helps,
Mike Imel

Date:         19960813
From:         Ben Day <>
Organization: Concurrent Sciences, inc.
Subject:      Re: Second time!! Soft-Scope debugger and protected mode
On Tue, 13 Aug 1996 Dion Burger wrote:
Can anyone give me an example or direct me to info on how to access physical memory above 1MB real mode space, and how to use protected mode interrupts with the Soft scope debugger?

I have a custom protected mode interface but cannot use it to debug 386ex apps with the Soft scope debugger. I also don't have any support to handle interrupts in protected mode!

Murfy was also sure that no examples on how to handle the above cases were included with the Soft scope package. Sheeeshhh :-(

Concurrent Sciences does read and participate in the 386ex list as a service to the 386ex community when time permits and when we feel we have something of value to add to the discussion. However, since the major topic of the list is the 386ex, we do not feel the list is the appropriate place to provide customer support.

It is the policy of Concurrent Sciences to provide the best possible support to Soft-Scope customers with a current maintenance contract. However, I have not been able to locate you or your company in our customer database.

In order to assist you in resolving any of the above mentioned problems that are related to our Soft-Scope debugger, I would request that you e-mail your serial number to us at along with a detailed description of the problem or you are welcome to call our tech support staff at (208) 882-0445.

With regards to accessing memory above 1M, there are several techniques that are commonly used. However, which method is best or which will work depend upon your hardware.

These techniques include:

  1. Use a BIOS call -There is a BIOS call that will copy a block of memory above1M to a buffer below 1M. This is a good quick and dirtymethod if you are trying to access a memory mapped devicein the extended address space such as a frame buffer.
  2. Use a DOS extender - DOS extenders provide numerous services to assist withaccessing extended memory. However, all of your code willbe executing in protected mode. Adding a DOS extenderto a legacy application can involve a lot of effort.
  3. Roll your own - Clearly, this is the most challenging method. Yourapplication would have to switch into protected mode,perform whatever memory operations are desired and switchback to real mode. However, all of this must occur withinterrupts disabled.
  4. Use DMA* - Jim Stewart previously suggested a very interesting ideainvolving the use of DMA* to transfer blocks of memory intothe real-mode address space.

I don't have any experience with DMA*, however, I have worked to some extent with the the first three methods. Each has varying tradeoffs. The first three methods are discussed in several different books if you are interested in learning more about them. Tomorrow, I will try and post a reference to a book that discusses these methods in detail.

Ben Day
Software Design Engineer
Concurrent Sciences, Inc.

More about this issue:

Date:         19960806
From:         Jürgen Hofmeister <>
Organization: Kontron Elektronik GmbH
Subject:      Re: emulator for 386EX wrote:

We're getting ready to design a board using the 386EX. I'm looking for a good emulator, any suggestions?

Kontron (Now Hitex, Jaap) offers two emulators for the 386ex.

The KSE5 system is a fully featured emulator with a lot of hardware breakpoints, trace with 15ns timestamps and overlay memory.
The DProbe386EX is a entry system for lower budget but still a complete emulator featuring also trace and overlay memory but a smaller selection of hardware breakpoints.

Both of the systems are using the Intel Bondout CPU, have a very strong macro language and fast download speeds.

More information is on our webpage or available directly.

Date:    19950804
From:    Byron Lunz <>
To:      (Recipient list suppressed)
Subject: New 386EX Emulator

Please excuse this unsolicited email, but because you are a member of the 386EX Mailing List which I maintain, I'm hoping you will be interested to learn about a new low-cost 386EX emulator now available from Microtek, the PowerPack SW-386.

The U.S. pricelist for this system starts at $4,995. It includes our powerful Microsoft Windows interface called PowerPack SLD. Probes are available for both 386EX (B-step) and 386CX/SX.

If you would like to know more, please visit our web site at URL: - follow the 386 link

If you don't have a web browser, you can get the details by auto-reply email by sending a message to SW386-INFO@MAILBACK.COM and the info will be in your mailbox within a minute or two.

And if you have specific questions, just write us at INFO@MICROTEKINTL.COM.

Thanks for your attention.

local - See the other families of processors.

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