If I remember correctly, IBM released the XT 286 when the second generation
PC/AT (with a faster clock - wasn't it 8 MHz?) came out. It was my
impression then that the XT286 was an XT case with the older original AT
motherboard inside.
-----Original Message-----
From: Mike Allison <mallison(a)konnections.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Thursday, January 29, 1998 10:04 PM
Subject: Re: Development, round II
>Tony:
>
>I just seem to remember _something_ about the XT286 that made me avoid
>it for true 286 stuff. Maybe it was the memory. Most after market AT
>boards had room for a meg or two. Maybe it was the 640...
>
>-Mike
>
>Tony Duell wrote:
>
>> I've not got the XT-286 techref to hand, so I can't look at the
>> schematics. But I seem to remember that it's _very_ similar to the PC/AT
>> - it's a lot closer to that machine than to the XT. There are 2 DMA
>> controllers, 2 interrupt controllers, the 8042 keyboard controller (so it
>> takes an AT keyboard), etc. My thoughts when I looked at the schematics
>> were that it was a repackaged AT. Of course they could have missed out
>> the extra reset logic, but I doubt it.
>>
>> It does use a non-standard motherboard, though. The memory is a little
>> odd - 128K in DIPs (4 off 64K*4, 2 off 64K*1 for the parrity) and 2 256K
>> SIMMs for a total of 640K.
>>
>> >
>> > I guess....
>> >
>> > -Mike
>>
>> -tony
>
> > Sun SPAREprinter model QA-6, anyone know how to do a self
> > print test on this unit I can not find any buttons or anything;
>
> It will not do much unless you have it connected to a SPARCstation
> running NeWSprint. The SPARCstation also requires a special S-bus card to
> interface to the printer.
>
> In other words, you have either a worthless printer, or a good excuse to
> go get yourself a SPARCstation.
Oh, come off it! Surely there must be some way of finding out the
protocol and building an interface and/or writing drivers for another
machine!
Which reminds me - I have a couple of Diablo 630 printers with ECS
daisywheels which have strange edge connectors on the back. I am told
this is a Qume Sprint 3 interface - has anyone got a technical spec.?
Philip.
> I looked in my never used copy of os2 version 1.3 standard edition and found
> no mention of rexx so maybe it arrived in version 2.x but i'm not opening my
> shrinkwrapped version to find out! minimum requirements for 1.3 are a 286,
> 2meg, and 12 meg of hdd space.
Worth a try then. But am I right in thinking that the AT doesn't
implement all the 286 modes properly? I'm sure the XT286 doesn't.
In a message dated 1/30/98 6:49:52 AM Central Standard Time,
Philip.Belben(a)powertech.co.uk writes:
> > In other words, you have either a worthless printer, or a good excuse to
> > go get yourself a SPARCstation.
>
> Oh, come off it! Surely there must be some way of finding out the
> protocol and building an interface and/or writing drivers for another
> machine!
>
umm, the Sparcprinters are pretty useless without the card and the software.
They really are dumb printers. I might have an old CD of NeWSprint, but then
you might have licensing issues to deal with.
Kelly
KFergason(a)aol.com
Tony Duell wrote:
> I suspect the real collectables will be the really obscure machines -
> development systems, parallel machines, experimental machines, etc. No
> idea if any will ever turn up second-hand, alas.
Whyever not? You got a DAP didn't you?
Philip.
I started a lot of debate when I wrote:
> Worth a try then. But am I right in thinking that the AT doesn't
> implement all the 286 modes properly? I'm sure the XT286 doesn't.
The two rumours I had heard are thus:
1. The AT had been deliberately set up so that it couldn't make one of
the transitions between modes - IBM were being paranoid and thinking of
crackers having a back door - but this "feature" was removed in the
PS/2.
This is obviously a garbled version of the things you've all been
telling me about 286s and the AT having to reset itself from time to
time. Thank you for clearing this up.
2. Intel had a fault on a large batch of 286s that couldn't do some of
the things you'd expect. IBM bought a job lot on the cheap and stuck
them in XT286s.
Can anyone tell me the origin of this latter rumour? Has it now been
discredited?
BTW What is Warp? Is it the OS/2 windowing system? If so, why would I
want to use it at all, let alone on a 286? ;-)
Philip.
PS *** Off Topic ***
I stand corrected. Uncle Roger is quite right about triangular manhole
covers. However I don't know whether this still holds up (pun intended)
if you have rounded corners and a thickness that is not negligible as
well as the lip to support the cover in its normal position.
I don't intend to try it to find out. Whoever posted that rather silly
message about System/36 was right - this discussion has probably gone on
too long.
I will leave you with a thought: Make the cover a triangle, but with
the sides arcs of circles centred on the opposite corner. (This works
for any odd number of sides, like the 50p coin I mentioned earlier)
P.
Does anyonehave the numbers to enter for an RD54 to put in a MicroVAX 2000?
II think I need the actual h/c/s numbers rathert than the MSCP ones in disktab...
The RD53 is full of errors, and this '54 seems to be woorking fune, so I'll LLF it and see about installing.
-------
>And you'll have to pardon my ignorance of the Intel parts after the 8085,
>but why wouldn't a 386 work if the 486 works? (Other than the speed
>difference.) It has always been my impression that few OS's/applications
>need whatever extra software features that differentiate the 486 from the
386.
I believe the 486 was supposed to be just a 386 with a built-in math
co-processor. Then Intel came out with the 486SX. Which was really just a
broken DX, a 486 in which the built-in math co-processor didn't work.
-- Kirk
At 08:36 PM 1/29/98 -0800, you wrote:
>> Also, what's a fair price for a Coleco Adam system: 2 keyboards, memory
>> box with datacassette drives, external numeric keypad with knob (paddle?),
>> and printer.
>
>$25 - $30 as long as it works.
I have to disagree here... I'd say $50-75, possibly as high as $100 with
the extra parts, depending on how badly one wants one. (Again, assuming
it's working.) Mind you, that's what I'd feel comfortable selling it,
wihtout feeling like I'd ripped someone off. I don't know if I'd pay that
much right now, but catch me in a good month...
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.crl.com/~sinasohn/
Some things that I would like to find are an Apple //e system, a copy of
Networks II BBS, and a copy of Nexus BBS. I'm pretty sure that along my
travels I will eventually find the Apple //e but I don't know if I have a
chance of finding either piece of software.
I've done a lot of searching on the web, but I haven't found anything.
Does anyone have what I'm looking for, or are there any resources I may
be missing?
Thanks,
Mike
