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Grex Micros Item 84: I'm having trouble assembling old DOS system.
Entered by kaplan on Fri May 13 22:32:05 UTC 1994:

I am trying to put together a DOS machine for a friend.  It says "Dell
System 200" on the front.  My friend bought it used from Arbornet at the
March JCC sale.  It seems to be a full-sized AT with space for 2
full-height drives in addition to the half-height 5.25 floppy it came
with.  He also gave me a monochrome monitor which looks really old.  It
has a D shaped 9 hole connector on it and comes with a cable which has D
shaped 9 pin connectors on each end. 

Is this likely to be a standard pre-VGA monochrome monitor?  There is no 9
hole socket here to plug the monitor into.  But there is a card with 3
connectors: D-25 hole, D-15 hole, and D-25 pin.  This card has 54 chips in
6 banks which I presume to be RAM.  Is this a video card? Can I get a
cable or adapter to mate this card with the monitor?  Can I get a monitor
to plug into this card? 

There is a half height hard disk which does not fit into either of the
bays very well, but you can sort of get it to stay there with one screw.
It says, "Seagate ST-225" on it and I think it came with an XT. I also
have a hard disk controller with only one edge connector, so I assume it
is also XT-style.  Can an AT use an XT disk and controller? 

If I can't get this system to work, any cheap DOS machine will work as
long as it can run dbase IV.  I presume that means it needs at least a 10
M hard disk, and at least a 360 K floppy.  It also needs to be connected
to a printer.  It's for a non-profit organization.  Does grex still have
an old computer to sell?  Does it have a hard disk? 

Thanks.

4 responses total.

#1 of 4 by davel on Sat May 14 00:41:19 1994:

The one thing I know (or have been authoritatively told & it fit what was
happening) is that XT & AT hard disks have different low-level formats, so
you're likely to have to run a low-level format on it.  On some old
AT-class machines you did this by issuing some command via debug to cause
it to run a bios routine or something like that - but there are also
commercial programs around.  (I know Checkit comes (or came) with an AT
low-level format program, to name one.)  I am pretty sure that an ST-225
should work fine on an AT, FWIW.

I expect some of the hardware gurus around here can answer the rest of
your questions as well as expanding on that.

#2 of 4 by jep on Sat May 14 02:00:06 1994:

        I asked Jeff to enter this item because he tried asking me in "talk"
over on M-Net, and I was on the phone at work with a customer.
        The ST-225 is a 20 MB MF/M hard drive made by Seagate; very popular
around the time the AT came out.  That was in 1986.  This is an old hard
drive.
        You can install an ST-225 on an AT computer if you attach it to an AT
MF/M controller.  It has 615 cylinders and 4 heads, 17 sectors per track;
it's the standard AT type 2 hard drive.  Hook it to a controller, set the
BIOS to make the first hard drive type 2, then get a low-level disk
formatter, such as Disk Manager, and low-levl format it.  You can then use
a standard set of MS-DOS disks (any version) to partition it and format
it.  If all of this means little to you, you'll need someone to help.
You'll need an MF/M controller and a thin and thick drive cable set.
        I don't remember this computer, and don't remember if it works or
not.   (I ran the Abornet table at the JCC Sale.)  We tested everything we
could, but didn't make any promises, other than that if you saw it work at
the sale, we confirmed that it would run then and there.
        The card sounds like an AST 6 pack card.  If it's 8 bit (there's no
notch in the expansion slot interface) it's probably a serial card (the
male pins), parallel port (the female pins), joystick port (the 15 pin
port), and possibly a memory card.  It may function as a clock, too, on an
XT computer, with an appropriate driver, but that function is not needed
on an AT computer.
        An AT case is a standard sized case; you could install a new
motherboard and power supply in it, add memory, a hard drive, and
expansion cards, and have a good computer.  What you have, if it works as
is, is a decent DOS computer, or a very feeble Windows computer.  It
probably will not run OS/2, or any version of Unix except Coherent or
Minix or SCO Xenix 286.

#3 of 4 by kaplan on Sat May 14 05:24:01 1994:

OK, I understand all that.  The card with lots of connectors does not have
a notch so it may well be the 6 pack.  I don't need any of the connectors
but should I leave it in for the memory?  The mother board has 4 things on
it that I presume to be SIMMs.

The hard disk controller does have the thick and thin cables but no notch
in the edge connector, so I presume that makes it not an AT MF/M
controller you said I need.  How can I tell if it is MF/M?  Where can I
get the right AT MF/M controller?

And I still need to know where I can find a video card with a D shaped 9
hole connector on it for this monochrome monitor.

And if I get past all that, I'll need to know how to get in and "set the
BIOS." You did that on my old Zenith AT by hitting ctrl-alt-insert but my
friend's AT clone only lets you configure things like that with a program
that was in her \DOS directory. 

And finally, where do I find that low-level formatter I'll need?  Is "Disk
Manager" something I can get for free via ftp?

John, if you can help me find the disk controller and or video card,
there's a socket driver in it for you in addition to a fair price for the
components.  ;-) Thanks for your help.

#4 of 4 by jep on Sat May 14 14:04:20 1994:

        You can use any video card for a PC; 8 or 16 bits, either will do
fine.
        For an MF/M disk controller... I really don't know where to find one,
other than in my own computer.  Unfortunately I need that one.  Post
something in classified, I guess.
        Some BIOSes are accessible through CTRL-ALT-ESC, some can be accessed
by pressing <DEL> when the computer is booting (these will usually tell
you to "Press <DEL> to enter setup" or something similar).  If you need a
program to enter setup, I don't know where to get one.
        If you find a copy of Disk Manager, it will allow you to define a
hard disk type and store the information.  I suggest calling CCS
(747-8440) and asking if they have one you can have or buy.
        You will need to get SIMMs, the 6 pack memory will not do for a
replacement.  I don't know if it will work in an AT at all.  Everything I
know about computers, I learned on 386's, other than DOS commands and
other basics.

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