Uncreative Labs

Joined: 05 Aug 2008 Posts: 23

Just got a stock 5170 (IBM AT). This one has an 8MHz 80286 and 640kB of memory. Looks like a 30MB Seagate hard disk and a True Blue EGA video card.

I'd like to add memory to the computer, but can't remember how to do it. I have a couple of Above Boards sitting in a box. Each is populated with two megabytes of memory. I'd like to install both cards so that I have 384kB of extended memory and 3600kB of expanded memory.

If I remember correctly, these boards support EEMS 4.0. That means that the system should be able to "bank switch" programs from expanded memory into conventional memory under something like DesqView. In other words, the system should be capable of multi-tasking with EEMS 4.0 memory installed?

I'd also like to install a 16-bit Promise IDE controller and 425MB Western Digital hard disk. The controller and hard drive date to about 1994 and were originally in a 486, but I can't see any reason why they wouldn't work in the AT as the controller has its own BIOS. I can't remember whether I should tell the AT that it has type 1, no hard drive, or "user defined."

Finally, I have an ISA Mach32 card with 2MB of memory. I also don't see any reason why this won't work.

Oh yeah....I have a 16-bit 10/100 card. Can I install a packet driver, hook this card up to my router, and use lynx or whatnot for e-mail and usenet?

Thanks in advance.

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Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

All of the things you mention above should be possible. For the Above Boards you'll just need to get the software to configure them.

I don't know about the Promise controller. I always have problems with Promise products. I recommend going SCSI if you can manage it.

Just about any 16-bit ISA card should work in an AT, with the possible exception of some later PNP cards (but those might not work well in a 486 either)

Have a look at my AT (and be jealous Razz

)

http://picasaweb.google.com/misterzeropage/MyVintageComputerStuff/photo#5219441981389018754

Joined: 05 Aug 2008 Posts: 23

That is a nice system you have there, AC.

If I could scrounge up an Inboard 386/AT (they pop up on eBay now and then), would I be able to replace the 386/16 with some kind of 486 upgrade chip? I vaguely remember that there was a 486SLC that had a 386SX pin out and would run in 386 boards. It looks like your "Make it 486" plugs right into the 286 CPU socket though?

What I'd really like to do is get the 5170 to run some flavor of Linux so that I can run a listserv on the machine. I think that the 386/16 Inboard and maybe 32MB of ram would do the trick. I found some unmarked ISA memory boards that hold four 30pin SIMMs each. If I could populate each board with 4 - 4MB SIMMs that would give me 32MB, plus 1MB on the Inboard and 640kB on the planar.

Another option might be to replace the crystal on the Inboard so that I could run a 386/20 or 386/25.

Any ideas are appreciated. Smile

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

Does the inboard 386 AT use a 386SX or a 386DX? I have an Inboard 386 PC, and it uses the DX. There was a user in here that replaced the 386DX on his Inboard with a Cyrix 486DRx2 (clock doubled) chip and ran at 33MHz. There is also a clip-on version for the 386SX called the Cyrix 486SRx2 which I have installed in one of my other systems. A Texas Instruments ti486SXL or ti486SXLC would be a litte better since they have 8kb cache. It's possible to find better upgrade chips, but they're usually more difficult to find. For example I have a Blue Lighning upgrade chip for a 386DX socket that supports a 4x multiplier and has 16kb cache, but it's quite uncommon. Some of the fancier upgrades might not be easy to get working either. Your best bet is to use a product that plugs directly into the 286 socket.

Your plan for a 32mb AT is interesting, but unfortunately it won't work. If you remember the ISA bus only has 24 address lines, which allows for a maximum of 16mb DRAM. The only way you can get around this limitation is to use an upgrade board which has the memory directly on it and uses a fully 32-bit CPU. I know the Inboard uses local memory, but if I recall correctly it only goes up to a maximum of 5mb or so using proprietary expansion modules. However, it is still ideal to use them as they run at 16MHz rather than the 8MHz planar memory. Of course you can always configure up to 32MB as LIM 4.0 EMS memory, but I don't know that linux can use it.

Linux will of course run on an AT with a 386/486 upgrade, however you will find the memory speed to be quite a bottleneck, and it should still run relatively slowly.

Joined: 05 Aug 2008 Posts: 23

Thanks for reminding me about the bus limitation. I forgot that 386 class machines run their memory on a local bus. There are add-on cards for the Inboard that will take up to 4MB of memory, but I am uncertain as to how many of these cards can be piggybacked. If it is just one, then in theory I should be able to have 5MB of "fast" memory and 16MB of memory on expansion cards at 8MHz, for a total of 21MB. Does this sound about right?

I'm still intrigued with the idea of changing out the crystal on the inboard to see if I can run a 386/33 or 386/40. I suspect that the memory would not like this unless I swapped out the chips for 60ns or 70ns

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

I still think you'll end up being limited to 16mb, but it really depends on how the inboard handles the memory. For example, if the memory on the inboard is counted before the memory on the motherboard and ISA bus, then you will be stuck with up to 16mb. However, if you can configure the inboard memory to be counted at the end, you might be in business. But personally I think it makes no sense to have the fastest memory at the end of the pool...because you'll rarely be able to take advantage of the extra performance. It's possible that you might be able to build your own SIMM memory module for the inboard, but who knows if the board would actually see anything above 5mb.

I think you might be able to pull off a 20MHz overclock on a 16MHz inboard, but it really depends on the tolerances of chips used on the card. I tried overclocking my AT motherboard from the default 8MHz, but I learned that the DMA chips and the memory controller will act goofy if I push the system beyond 10MHz. It's definitely possible to replace these with better parts, but it's often not easy to get the replacements.

I think your best bet is to try overclocking the inboard to 20 MHz, and then popping in a cheap TI486SXL chip and enabling the clock doubling via the cyrix control utilities to run at 40MHz. As I said before, this chip has 8kb internal cache which will give a substantial performance boost.

I should really keep my eyes open for one of these inboard ATs. I really wouldn't mind having a few megs of fully 32-bit memory.

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

I've been looking into Inboard 386/ATs. It seems that unlike the Inboard 386/PC they do not come with any memory. In the case that you are not able to fix the memory module for the card, you would probably be better off with a regular 386 upgrade module.

Joined: 19 Apr 2006 Posts: 261 Location: WisConSin

But the Inboard 386 DX for ATs had 32bit cache Smile

And there were Inboard/286 models that had 256k of ram expandable to 1mb using chips and further usign piggybacks.

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

The cache isn't worth much when you can use a hybrid cpu with 8 or 16kb or better L1 cache. The memory performance on a standard 8MHz AT planar is pretty lousy compared to any real 386 system. The Inboard 386/AT also has memory expansion connectors, it just doesn't come with any standard.

I'll have to read on this inboard/286. I take it this product is for an XT?

Joined: 03 Feb 2006 Posts: 488 Location: pennsylvanai

memory card
at the risk of repeating the (correct info) posted.
the Intel boards I have store the info in non-volitile memory. the software is required and you set the beginning (512m?) and then the rest of the memory of the card up to 16m max
I asked intel in the early 1990's and they told me that there is NOT and would NOT be software to exceen 16 megs of ram.

controller card
the boards will work in ISA 386 and 486.
I have (somewhere the POWER IDE) cd and cards.
normally, the best you can expect is a wd1006 controller ( 1:11) with a mfm drive.
the wd1007 (esdi card) looks the same but will brun out a mfm drive. ( same connectors different pinout)
this offers a performance increase THO.

Bios,
the generic setup.exe or setup com will work and be better and easier to use. gsetup .exe is also ok.
later bios ( non ibm) may work and convert an original at mb to newer setup.
I copies a pair of VSLI bios chips and it worked in an original-type AT clone mb.
it has type 47, diags and interleave tests.
when I was at intel PRO on 1979, a repair added 3rd party bios to a IBM AT. it worked.

All my promise cards are PCI, but there are gaps in my experience
and promise made other cards ( before Local Bus and pci) DTC made some enhanced ide (isa) cards)
best if you can to use a ide drive as mfm/rll drives are getting rare.
the adaptec scsi cards are common. they have floppy controllers and ignore the mb bios
so other scsi drives can be used
remember there is a 2,048m (16 bit) limit.
but you can divide a 4g scsi drive into c: and D:

Posted: Tue Mar 10, 2009 4:44 am

i've got a 16bit adaptec scsi card that is currently sporting a 4gb scsi drive. you have to use a special partitioner, otherwise the controller will only see EXACTLY half the drive's capacity my card is a AIC-6260al made for a compaq, i've got a 9gb full height behemoth i'm going to try to get working with it. Use EZSCSI 4. You can get it at Vetusware.com *lots of old stuff* afdisk and aformat are the way to go. but don't expect to boot from it, at least on my card you can't, it's got a bios, but my MFM supercedes it.

Joined: 03 Feb 2006 Posts: 488 Location: pennsylvanai

I have a make-it 486 here ( in my hand)
i think they were originally intended gor only IBM's
and there wasn't enough space for the card in other brands.
I have not popped off the heatsink so i don't know which 486
but it says" 486/33 pd3 fcc id jic486-33pd3 rev a7