kds@intelca.UUCP (Ken Shoemaker) (08/19/84)
>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 Actually, no, both the PC and XT have the socket for the 8087. In addition, I see no reason why a disk controller would require plugging in a ROM into the PC, it could just as easily put the ROM on the controller board.....Supposedly, there is code in MSDOS to check certain locations for the existance of ROM-based controller firmware. -- Ken Shoemaker, Intel, Santa Clara, Ca. {pur-ee,hplabs,amd,scgvaxd,dual,idi,omsvax}!intelca!kds ---the above views are personal. They may not represent those of Intel.
Burhans@ECLD.#ECLnet (08/21/84)
From: Jacqueline <Burhans@ECLD.#ECLnet> 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. -------
tomk@ur-laser.uucp (Tom Kessler) (08/21/84)
The newer version of the PC known as the PC-2 (it tells how to tell them apart
int the technical manual and the guide to operations) has a slot for an
8087 and the exact same power supply as the XT.
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Tom Kessler {allegra |seismo }!rochester!ur-laser!tomk
Laboratory for Laser Energetics Phone: (716)- 275 - 3786
250 East River Road 275 - 3194
Rochester, New York 14623ojs@fortune.UUCP (Oliver Sharp) (08/22/84)
A previous posting said the PC-2 has a slot for the 8087 and the XT power supply. Well, both the PC-1 and the PC-2 have that 8087 slot and neither of them has the beefed up power supply. I have a PC-2, so I know. The difference between the two is that the system board on the PC-2 has room for 256k instead of only 64k and the 8088 in the board is the new one that is needed to use the 8087. Some of the older PC's had the old 8088, so IBM distributes the new one with the 8087 in their Co-processor package. Most people have the new one anyway, but it doesn't hurt to switch. Oliver Sharp ....!fortune!ojs