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From: Burhans@ECLD.#ECLnet
Newsgroups: net.micro.pc
Subject: XT vs PC + Hard Disk Add-on
Message-ID: <12491@sri-arpa.UUCP>
Date: Tue, 21-Aug-84 00:37:05 EDT
Article-I.D.: sri-arpa.12491
Posted: Tue Aug 21 00:37:05 1984
Date-Received: Sat, 18-Aug-84 01:13:16 EDT
Lines: 65

From:  Jacqueline 

My department recently purchased 2 IBM PCs and 2 Maynard Electronic
10MB hard disks (on my recommendation) for our word-processing de-
partment. One of the main differences between a PC with a hard
disk and an XT is that the PC costs (sometimes a great deal) less
money than the XT. But, like most things in life, it's not that
simple. First, some basic differences between the PC and XT (besides)
price: the XT has 8 expansion slots to the PCs 5, the XT has a
socket on the motherboard for the 8087 math co-processor chip (the PC
I believe, does not) and the XTs power supply is more *power*ful than 
the PCs.

If you decide to buy a PC and add a harddisk, there are several things
to consider; one of the most important is cost. The price for a 10MB
hard disk ranges from $895 (Kamerman labs), $989 (Maynard Electronics),
to $1500-$2500 (Corona,Davong,Tallgrass) all the way up to IBM's own
10MB drive for $3400. As with all major purchases it is important to
consider the size and stability of the company. I didn't go with
Kamerman although they were the least expensive because they were a
relatively small and relatively new company. As it turns out I sub-
sequently heard of incidents with the hardware not working as adver-
tised and the customers not getting much support from Kamerman.

Another important issue (at least for me because I wanted an internally
mounted hard disk) is whether the PCs power supply will be able to support
the hard disk as well as any other option cards you may have in the PC.
Apparently there has been quite a problem with hard disks which phys-
ically fit in the drive but which conk out the PC by requiring too much
from the power supply. Kamerman and Maynard, which use half-height 
winchesters, specifically advertise that they will work with the standard
PC power supply (though I read about someone having trouble with a Kamer-
man). So far (2 weeks) I have had no problem with the Maynard drive. You
might be able to purchase an XT power supply for your PC to get around 
this problem.

But, there are more things to worry about: will you be able to boot your
system from the hard disk as you can with the XT? Maynard provides a
hard disk BIOS chip that plugs into a socket on the PC (256k) motherboard
to take care of that. They also provide software to run diagnostics and
a driver program for PCs with the earlier 64K mother boards. Also make sure
that the ASSIGN command works with your hard disk. This DOS command lets
your PC pretend that drive C (which is what your hard disk usually ends up
as) is drive B or even drive A in case you want to run some software that
specifically needs drive A or B.

Another important consideration is whether the software that you buy will
work with your hard disk. Some software is copy-protected so that you can't
copy it to (and thus can't use it on) your hard disk which limits the use-
fullness of the hard disk (and of the software.) Also, if the program
makes use of standard DOS calls (BASIC calls?) it should have no problem
but if it bypasses those to write directly to the hard disk (BIOS?) it
may run into problems. As you can tell I am not at this time intimately
familiar with this particular issue, maybe someone can clarify this--but
it sounded like a small risk for my application. So far I have used only
DisplayWrite 2 and Lotus 123 (a little) and have had no problem.

There have been several articles out on the topic of hard disks and the
PC. The January issue of Softalk has an article called "Winchester
cathedral: Do you really need that much real estate?" PC Tech Journal
had an article called something like: "Upgrading a PC to an Xtra-T."
Another good source of information is hardware reviews on the hard
disk subsystems themselves. Anyway, as I said it's been two weeks now
for me and so far so good.
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