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k2x4b524p
Joined: 20 Feb 2009
Posts: 217
Location: Nor here nor there.
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Posted:
Sat Oct 24, 2009 2:11 am |
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my latest above board, with the disks provided by you on the forum Again thank you, i have another question about it. There is a socked labeled U95, Stason shows this socketeing labelled as an XT socket, what chip went in this thing? |
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T-R-A

Joined: 02 Oct 2004
Posts: 594
Location: Western NC
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Posted:
Sat Oct 24, 2009 9:39 am |
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Seems like there was supposed to be a cable (socket-mounted ribbon connector) running from some of the above-boards to the CPU or something else on the MoBo. U95 wouldn't happen to be a 40-pin socket, would it? And then again, I've never worked directly with above-boards, so who am I to know... |
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k2x4b524p
Joined: 20 Feb 2009
Posts: 217
Location: Nor here nor there.
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Posted:
Sat Oct 24, 2009 9:14 pm |
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nope, it's a 14pin DIP socket, but it's got a ds1489an/mc1489ap on it so i wonder if it's for the 1489s companion, the 1488? |
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wdegroot
Joined: 03 Feb 2006
Posts: 488
Location: pennsylvanai
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Posted:
Sun Oct 25, 2009 10:52 pm |
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there were several " enhancement boards"
made by intel for early 8088 and 80286 computers
the inboard? was a 386 16 ( not an sx that was a later
chip) it "sort of made the xt or close clone into a 385-16. it had the 40 pin socket and required a cable to the copu socket on the motherboard.
I think the original 8088 40pin chip was moved to the board from the motherboard. not 100% sure.
there were some huge AT 16 bit boards, these are what I think we are talking about.,
some may have uses 256k chips ( state of the art then)
and others used 1 mb chiops and the boards held up to 8mb of ram. More than one board could be used and as said before topped out at 16mb.
I sucessfully used these boards in 386 and 486 motherboards with the standard 8 mhz isa but.
later I got 4 4mb 30 pin chips and that was easier to dael with
somewhere, I may still have the manual
try not to ask unless you want to park a 25 foot
truck in the yard and unload the garage.
and go thru every box.
a old pc with 16-20 megs is HOT. has all the ram it can ever use.
there were some other boards and I DO recall one with a open socket near the rear bottom.
I have pieces somewhere for the extension
2 cards, a small"mb" and a fat cable.
you could connect two xt cases and add more cards.
the second MB was 5 ? slots and very few chips ( no cpu)
Lisa compton who ran the " final frontier bbs"
in paterson nj, had such a setup.
I later offered her some of the pieces . |
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T-R-A

Joined: 02 Oct 2004
Posts: 594
Location: Western NC
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Posted:
Sun Oct 25, 2009 10:56 pm |
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Walter,
Just out of curiosity---didn't the Above-Board require a "special" version of Windows (3.0 or 3.1) when installed on a 8088-system? |
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ryan

Joined: 19 Apr 2006
Posts: 261
Location: WisConSin
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Posted:
Mon Oct 26, 2009 1:15 am |
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T-R-A wrote: |
Walter,
Just out of curiosity---didn't the Above-Board require a "special" version of Windows (3.0 or 3.1) when installed on a 8088-system? |
Whether it was needed or not I never heard of the Above boarrd getting a special version but...
Actually Intel rewrote portions of Windows/386 (aka windows 2.1) for the Inboard/386 originally.
And apparently do to some outcry eventually rewrote Windows 3.0 for the Inboard/386 but did not wish to bother with updating Windows 3.1 to support the 8bit xt bus.
The Above-Board occasionally needed drivers but otherwise I don't remember anything windows specific about it except something about the memory hole and smartdrive.
Cheers
Ryan |
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k2x4b524p
Joined: 20 Feb 2009
Posts: 217
Location: Nor here nor there.
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Posted:
Mon Oct 26, 2009 2:19 am |
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I'm not running a CPU upgrade board, tis just a memory expansion card with an open 14-pin dip socket @ U95, Stason shows it being an XP socket, like some chip is required for the board to run in 8-Bit mode, i'm inquiring as to anyone knows what chip this might be.
Also got my 3rd XT yesterday, the keyboard is PRISTINE, so is the Amber mono monitor, the internal chassis is immaculate but the outside case is showing the starts of rust on one of the corners, i know where i can find a replacement. This baby was free, lest it meet the recycle bin |
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T-R-A

Joined: 02 Oct 2004
Posts: 594
Location: Western NC
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Posted:
Mon Oct 26, 2009 9:48 am |
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Quote: |
Actually Intel rewrote portions of Windows/386 (aka windows 2.1) for the Inboard/386 originally. |
OK, that explains it. I'm getting the Inboard confused with the Above-board... |
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wdegroot
Joined: 03 Feb 2006
Posts: 488
Location: pennsylvanai
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Posted:
Mon Oct 26, 2009 4:31 pm |
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as I remeber the inboard required a special version of windows
I have copies of all the standard versions of windows (oops now you know)
as well as several versions of dos and older apps.
I ran ran windows 3.0 on a 286-12
and I recall no colors excepot the splach screen.
I was given an odd-ball 285 board and they DID NOT KNOW, there was 1 m ( 8-1m dips) on the board
they took out the 30 pin ram sticks.
later I was given a 386-16 "daughter board"
and had a high speed 396 sx?-16 with 1 m ram and an amber monitor.
I later added 2 mor megs of ram.
BUT the 286-12 with 4m on the mb was faster.
and I added the above boards when the job tossed them out.
I thought I was in the BIG TIME |
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k2x4b524p
Joined: 20 Feb 2009
Posts: 217
Location: Nor here nor there.
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Posted:
Tue Oct 27, 2009 4:29 am |
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Back to topic. Above Board 8MB board
What chip goes into U95 to enable 8-Bit mode |
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wdegroot
Joined: 03 Feb 2006
Posts: 488
Location: pennsylvanai
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Posted:
Tue Oct 27, 2009 4:53 pm |
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I often wondered if the board could
be used in an xt ( 8088)
but the chip can only can see I meg of ram.
the board can be used for a big ramdrive.
there are some apps that conform to the L.I.M ( lotus,intel, Microsoft) specs and use that to make the program work better on that xt
Like handling big spreadsheets .
the other downside is the case will not accemt the tall board with the cover on.
and running Lotus on an 8088
with any amout of ram is STILL slower
than running the same program on a 386 with 16 or 20 megs of ram.
so really, It is an intereting thing
but it has no real world use. |
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T-R-A

Joined: 02 Oct 2004
Posts: 594
Location: Western NC
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Posted:
Tue Oct 27, 2009 5:28 pm |
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I think Geoworks supported LIM (on even an 8088), but Win 3.0 didn't (unless on a 386). Older versions of Quattro Pro also supported it (similar to what Walter mentioned) but LIM had such a short lifespan (virtually dead after EMS) that few developers even bothered... |
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wdegroot
Joined: 03 Feb 2006
Posts: 488
Location: pennsylvanai
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Posted:
Tue Oct 27, 2009 10:38 pm |
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an xt was useful in it's day
and with a V20 and 640k and a patch on the V20
setting the "wrong interleave"
wrong means too high which was faster than the RIGHT interleave.
a faster drive, like a st-251-1 ( 28 ms)
\and an ega card set for a cga monitor, one with decent dot-pitch. like .28
a better floppy controller and a 720 or 1.44 floppy.
Made for a pretty decent XT.
BUT it was still a mile behind the first 386. or a 12 mhz 286. |
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k2x4b524p
Joined: 20 Feb 2009
Posts: 217
Location: Nor here nor there.
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Posted:
Sun Nov 01, 2009 4:47 am |
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greetings again, i am bumping this post up a little further as i still haven't solved the problem and we've gotten a bit off topic for this one. The chip that goes into u95, any ideas? |
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