sid@linus.UUCP (Sid Stuart) (09/21/86)
I got sucked into working on my girlfriend's Compaq 286 computers, and there are some differences between it and other AT clones that I don't quite understand. I was hoping that someone on the net could and would enlighten me. 1. The Compaq appears to have a hard disk controller that is separate from the floppy controller. I need to buy another controller. I have seen controller boards for PC's, but not for AT's. Can I get another board from a third party vender, or do I need to go to Compaq? 2. The memory for the system appears to be kept on an Magnum expansion board. Or at least 512K of it is. On one system with 512K, the expansion board, which has 8 rows of 9 chipholders, is filled with 64K chips, great, that adds up to 512K. On another system that has 640K the expansion board has two rows of 256K chips. Wait, that only adds up to 512K. Where is the extra 128K coming from? is it mounted on the mother board? and if so, why don't I see it on the first system which also has 512K on the expansion board? 3. Is there are hardware reference manual, other than the worthless one shipped with the system, that would explain this beast in more detail? If so do you have an order number for it in case the salesman does not know what he is doing? Hoping for enlightenment, sid@linus
rdr@inuxh.UUCP (Robert Rindfuss) (09/23/86)
> 1. The Compaq appears to have a hard disk controller that is separate > from the floppy controller. I need to buy another controller. I have > seen controller boards for PC's, but not for AT's. Can I get another board > from a third party vender, or do I need to go to Compaq? > A warning from my experience - a Hardcard 20 from Plus Develepment will not work in a Compaq 286 Portable, or in the Portable II. Folks at Plus said they use different interrupts for the controller or something like that (the guy wasn't sure). This may apply to putting other controllers as well. Bob Rindfuss AT&T Graphics Software Labs ...ihnp4!inuxh!rdr
dan@prairie.UUCP (Daniel M. Frank) (09/23/86)
In article <301@linus.UUCP> sid@sandy.UUCP () writes: > 1. The Compaq appears to have a hard disk controller that is separate >from the floppy controller. I need to buy another controller. I have >seen controller boards for PC's, but not for AT's. Can I get another board >from a third party vender, or do I need to go to Compaq? > Compaq uses the Western Digital hard disk controller board, or so I hear. > [various questions about memory configuration] If you are asking about the Deskpro 286, it has NO memory on the mother board. There is a memory board plugged into one of the slots. It has 128K in funny shaped chips on two small soldered-in daughter boards on that memory board, and space for 512K of 64K RAM or 2 Mb. of 256K RAM, depending on how you set a jumper. Good deal, actually. > > 3. Is there are hardware reference manual, other than the worthless >one shipped with the system, that would explain this beast in more detail? > The "80286-based Products Technical Reference Guide" is very good (no bios listings, though). The part number appears to be 102786-001. It covers both the portable 286 and the Deskpro 286, but not (at least when I got it) the Portable II. -- Dan Frank
dan@prairie.UUCP (Daniel M. Frank) (09/24/86)
In article <477@inuxh.UUCP> rdr@inuxh.UUCP (Robert Rindfuss) writes: >A warning from my experience - a Hardcard 20 from Plus Develepment will not >work in a Compaq 286 Portable, or in the Portable II. Folks at Plus said >they use different interrupts for the controller or something like that >(the guy wasn't sure). This may apply to putting other controllers as well. The guy was wrong. I run a stock Unix port on my Deskpro 286 (which uses the same interrupts as the portable 286), and it runs just fine. Doesn't use the BIOS, so the interrupts must be the same. In fact, the behaviour of the controller board must be identical to that in the AT, also. By the way, I forgot to ask the original poster why he needs another hard disk controller for the 286: the one that's in there will support two hard disks. I built a new daisy chain control cable and outboarded a Toshiba 72 Mb. drive; works great. -- -------- Dan Frank uucp: ... uwvax!prairie!dan arpa: dan%caseus@spool.wisc.edu