Obsolete computers still live. Sometimes they need parts. 

36 responses total.

I use a True Blue XT at my office (they've abandonded PCs - gone all
Mac - but I find it handy for people that wander in off the street 
with the "wrong" OS), which has 256K RAM built in and 256K on an AST
"Mega-whatsis-II" board, whose clock has fritzed. I need those 128K
more the XT allows, so am looking for either a used AST board with
384K aboard, or the "Piggyback" board that goes on it, with 128K. 
Anyone have a dusty ziploc on their shelf with one of these?

try entering thhis in the classified conf, also.

Rane.  I have some information on putting 640K on the mother board of
a genuine IBM XT.  As I recall, all you need is a hand full of 256K
chips (Jemmie as em for $0.60 ea), some common TTL chip, and add a jumper
to the bottom of the board.  Easy.  I did it to one of mine and it worked
fine!  Let me know if you want to persue this further.

Oh, I forgot.  I also have a 348K board I'll sell you.  Mail me if your
interested.

I'm still considering my options on the above upgrade. I could try klaus'
board, but it doesn't have a clock or serial port (which are on the
AST board in the machine (though the clock is fried)): therefore I'm
also looking for a serial/clock board, to put the "package" together.

Brief synopsis of instructional lesson in memory upgrade: n8nxf's (nee
klaus) 384K board works fine (thank you!); installed "cheap" serial+
parallel+clock+floppy-drive board for serial+clock, but my A: drive
became unworkable; tried all resident floppy driver board switches for
secondary ROM-BIOS and I/O locations, but NG; pulled humongous (48 pin)
controller chip on I/O board, and it worked! - except now had environment
space overflow; MS-DOS manual *useless* for expanding environment space;
had to go home, so computer spread across my office (found env space
expansion command in Jamsa's DOS); typical afternoon booting the PC until
it, and I, were blue.

Blue, huh, hmmmmmmmmmmmmm.

Yes, blue: an XT. Well, to continue the saga: found how to expand
environment with shell=c:\command.com /p e:256 in config.sys (but
wondered if there is another way), so that's OK; tried to use COM2,
but no go; clock all screwed up!; that "humongous..chip" must do
something else; must remove "cheap" serial+parallel+clock+floppy-drive
board and find a serial+clock board. Wow. I'm really saving money.

Isn't there a jumper that'll allow you to deselect the floppy port?
(Or just tie the interupt for the floppy inactive.  Cut the foil to
the buss first though, so you don't tie down the whole bus!)

No jumpers refer to controller. How does one "tie the interrupt for
the floppy inactive"? What is the "foil to the buss" that should be
cut? Actually, there is something weird about this board. It has three
chip sockets (two small, one big), which do not have chips. I initially
thought it might be a rework, but I find that I cannot "locate" either
COM2 or LPT2 with Norton SI, with the jumpers set so they shold be
enabled. Is it likely that a new board would come with some empty sockets?

Interrupt IRQ 7 is used for the floppy controller.  Your card plugs
into one of several edge connector sockets known as the XT bus.  On
this bus, pin B21 is IRQ 7. On your card there is a trace which 
connects to this point when the card is pluged into the bus.  Cut
this trace, but so it can be repaired should I be wrong.
That should do it.  The floppy controller on the brd. should be kaput.

I suspect that you don't have a COM2 chips on your board!  You need
to plug a UART (same as the one already on the board) and a couple
of quad line drivers (also same as those on the brd. for COM 1.
could be 1488 and 1489?)

(Forget what I said about tieing this and that inactive.  I was
thinking of something else....  Give it a try.)

I thought 7 was used for LPT2, and 6 was the floppy controller.

I pulled the board and called the vendor. They'll take it back. I
ordered separate clock and serial boards for total $$ slightly less
than the composite board. But add trip and $$ UPS for return. I was
tempted to start to muck with the composite board "because its there",
but, enough already. However, for the aficiandos, the shmanual (that's
a sh--ty manual) says IRQ7 is LPT1, but doesn't say which is the
controller interrupt (though IRQ6 is available). The shmanual says
nothing about the controller (the board also has "timer 1" and
"timer 2", with nothing in the shmanual what the difference is or
why one would want one or the other). This must all have something to
do with the board having been made in China, and the chips are variously
labelled "singapore", "malaysia", "thailand", "goldstar" (sounds like
a cruise ship to southeast asia ;-)). 

Handy PC IRQ table:

IRQ             Use
---             -------------------
 0              Timer 0
 1              Keyboard
 2              unused (PC) or cascade to secondary 8259 (AT)
 3              COM2 (if installed)
 4              COM1
 5              LPT2 (if installed)
 6              Floppy drive
 7              LPT1
 8              CMOS real-time clock timer
 9              unused, wired to old IRQ2 line on system bus
10              unused
11              unused
12              unused
13              unused
14              Hard drive
15              unused

Note that interrupts 8-15 are only present on AT-class machines, and
are cascaded through to the secondary 8259 interrupt controller.

Bad board shipped back; new boards arrived today and installed. Everything
works fine! End of stirring XT upgrade saga. Thanks to all those that
helped, commented, made witty observations. Now...I'm about to tackle
adding 2 M expanded memory to my Zenith 151. I am sure I will be back 8-).

REALLY?!?!?!?!?!?!????????

Yup. What's wrong with that?

REinforcing your   "8-)"  ...

Got it! 

Whoops I meant LPT1 in #12.

(Footnote to XT upgrade, or, "it never ends": with new memory, ports and
clock, LOTUS123 wouldn't work. After a few more hours......found it was
the time display the clock board put in the corner where the MODE display
is located. Disabled clock board time display....sigh.)

Aren't there selectable corners for those things?

There would be on a Mac, where the clock is in the menu bar, and cannot
interfer with applications. However on that XT - I don't know of a way
to move the Lotus indicators, and the clock software has no options. One
way around this would be to start Lotus from a .bat file, which first
dismounted the display, which is a TSR. Is there a generic way to do
that? (The clock software doesn't have - or at least tell one about -
a command to remove the display.)

<< Goldstar >> Hello Rane, most Intel CPU now are made in Malysia.
Seagate manufactured their drives in Singapore + Thailand.
Quantum + Maxtor also have giant factories in Singapore.
Goldstar is the old name for giant Korean company that manufacture
most DRAM/memory chips today. They change their name to LG
(From Lucky Goldstar). Best regards (AW)

Those don't sound like obsolete computer parts....but, of course, they will
be... ;->

Hello Rane, I ask top Intel Exec, they say that anything bleomw 200 MHz
or less than Pentium II is dead duck. When I ask about 440LX or
82460 or 82450NX or Slot 2 CPU, he cannot give any comments.

It is strange that every PC you buy will be obsolete by the time you open the
box in your home/office. :-) Regards (AW)

That Intel Exec obviously works for Intel's computer consumer division
and has little knowledge of the commercial / industrial side.

I certainly wouldn't say that anything less than a Pentium II is dead.  For
one thing, the Pentium II is separated from the PPro by stuff that will only
slow you down, if anything, for non multi-media stuff.  For servers, the
Pentium Pro is better.  The regular old Pentium is still being put into
service for lots of applications that don't require really heavy horsepower
as well.  It will probably be on its way out sometime soon, but it isn't yet.

For some applications, even the Pentium is overkill.  The computer I'm still
using at home is a 486DX2-66, which is long since obsolete.  All I use it for
is as a fancy terminal, so it's more than adequite for what I use it for. 
Of course, I do have a reasonably nice Pentium on my desk at work, that I use
for any serious stuff.

Since this item picked up after a four year lapse, I read back through
it. Sigh...I still haven't installed that 2M of expanded memory into my
XT class Zenith (151). I can't wait....(but have).

But even an XT is not totally obsolete. I think I mentioned this in another
cf - but it is apropos here: I picked an HP PCL (bitmapped) graphics file
off the web and could find not way to print it via my PowerMac. However -
XT to the Rescue! - it printed fine from the XT to a DeskJet printer. The
only potential problem was that the XT (class) had never seen such a big file,
and I had to make room on the 20M HD to load it.

The XT is only dead if your trying to run Windoze 3.1, NT, 95, etc.
They are just fine for communicating with Grex, word processing, spread
sheets, etc.  All you need to do is find software that will run on these
older machines.  I even had someone load Windoze 3.0 on to a XT that I
had loaned them.  It worked!  On a 20M HD yet...  For a spend-thrift,
having $1,000 in your pocket instead of a mediocure Pentium on your 
desk, a XT can make a lot of sense.

This seems to be about the best item for this:

I'm hunting for jumper setting on an IDE HDD Controller, which may or
may not have been manufactured by Xetec the only info I have on this
thing is what is silk screened on it:

DT-3767
P/N:ZA-HFC42-21A REV. C

And on a sticker:

S/N: 226192

There are three jumpers and I need to know which ones I have to play
with (if any) to set this as the secondary HDD controller

any suggestions where to look? I think I"ve exhausted my search
possibilities on both HotBOt and Excite

while we're at it...is there any good use for an old Apple II? I've got
one, but I'd hate to throw/give it away

3 jumpers -> 2^3 = 8 -> 8 possible combinations, so you aren't that bad off
just trying them?

I tried that, but it just didn't seem to work, do you need a different
sort of card to use as a secondary controller?

While others are working on Joe's questions, here is another search for
obsolete (it seems) parts..associated with a 486 machine! (I asked in
another item, but am repeating it here, with update.) I need the
cables/adapters/interfaces to connect to two pcmcia cards in a Thinkpad.
The cards are:

  Modem:     Optima 144 model 5118AM
  Ethernet:  Xircom IIps  model PSCE2-10

I inquired of PC-Mall, but they said they don't have them, and suggested
Microwharehouse. MIcrowharehouse has not answered my inquiry. What's with
these things? I read elsewhere that a problem with pcmcia cards was
fragile and hard-to-find adapters/cables. That seems to be the truth. 

rane: I'm not sure it's what you need (mainly because I don't remember
the make of the ethernet card I have) but I may have a cable for
you...lemme check it out tonight (when I get home) and if it's what you
need I could probably give it to you if you felt like dropping by the
Heidleberg on the 1st sometime after 8 P.M.

Of course, I'm not sure how we'd recognize each othr...but if I have
what you need we can work something out (figuring out the identification
thing that is....I don't need the extra cable)

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