phipps@garth.UUCP (Clay Phipps) (12/28/88)
In article <1381@cps3xx.UUCP> jhl@frith.egr.msu.edu (John H. Lawitzke) writes: >I am considering upgrading my current system. >I currently have a IBM XT 4.77MHz ... I have comments that may be helpful, but close with *questions* of my own. I am trying to upgrade my machine to support PageMaker and lots of I/O devices (e.g., scanners, disks) primarily for personal use on behalf of a volunteer nonprofit tax-exempt organization (therefore, my employer indicated below has no reason to foot the bill). >...any experience with motherboard replacement [versus] accelerator cards...? I have a true-blue IBM PC-1 (4.77 MHz), whose BIOS I have upgraded to the 1st true-blue IBM BIOS that supports a hard disk (Oct. 1983 ?). I also have a Sigma Designs EWS-0000 expansion box, where most boards reside. Were it not for the expansion box, I would have problems with adequate power, excessive heat dissipation, and slot shortages. I chose to buy the intel inboard-386/PC board, which I was able to purchase for $750. A large part of the reason was that I could keep my true-blue BIOS, which should limit my compatibility problems to the inboard-386. Its incompatibilities are not trivial, because the board requires a special version of, e.g., Windows-386, and will not run stock OS/2 (the former is now available from intel PCEO for $99[?]; the latter is no problem -- I will install OS/2 when I install FORTRAN and COBOL :-). I don't know anything about UN*X ports for the inboard-386. I had only 320KB of system memory (including 256KB on an AST ComboPlus), so the 1MB on the inboard-386 is a welcome feature (2MB more can be added). If I had a clone motherboard with a clone BIOS, I probably would have decided in favor of a new motherboard, which would have gotten me 16-bit I/O, without risking much loss of compatibility. What I gain is a 16-MHz 386 with 32-bit access to the onboard 1MB; what I don't improve is the 8-bit bus that I retain for I/O. I expect that my extensive use of PageMaker will make far greater demands on computation than on I/O (whether to screen or disk). >...[On "]scrap the box and buy a new one ["] advice ... >...I'm not...interested in investing an amount that...could buy a new car... Obviously, I'm making drastic changes in my system configuration, so the "buy a new one" advice makes some sense, even using my own money. However, I will need very soon to replace a car with 178,000 miles on it. I can't afford to spend too much on my computer system at any one time. That argues very convincingly that I put in little improvements over time, rather than waiting until I can afford a big-bucks upgrade all at once. With incremental changes, I get an incremental increase in capabilities that I can use right then and there. Ultimately, this machine might be retired to BBS use, but no time soon. *Questions*: Are there limitations on the capacities of hard disks that can be run on such a system ? I assume that my system is a not-quite-XT for the purposes of selecting hard disks. The XT doesn't have a disk-type table, unlike the AT, as far as I know. I've read as much as I could find on disk selection, but have found no mention of limits; there must be some. Are all of the gritty details handled by the controller ? Which ones ? Having an apartment that gets *very* warm in the summer, I am reluctant to go with RLL's allegedly reduced margin for error relative to MFM. Are there any disk access speeds that don't make sense for such a system, providing performance that would be wasted by the 8-bit bus ? -- [The foregoing may or may not represent the position, if any, of my employer] Clay Phipps {ingr,pyramid,sri-unix!hplabs}!garth!phipps Intergraph APD, 2400#4 Geng Road, Palo Alto, CA 93403 415/494-8800
abcscnge@csuna.UUCP (Scott "The Pseudo-Hacker" Neugroschl) (12/29/88)
In article <2301@garth.UUCP> phipps@garth.UUCP (Clay Phipps) writes: >In article <1381@cps3xx.UUCP> jhl@frith.egr.msu.edu (John H. Lawitzke) writes: > >I don't know anything about UN*X ports for the inboard-386. SCO Xenix 2.2.1 release notes specifically mention the inboard-386. However, this may be the AT version of the inboard, not the PC. Good luck. -- Scott "The Pseudo-Hacker" Neugroschl UUCP: ...!sm.unisys.com!csun!csuna!abcscnge -- "They also surf who stand on waves" -- Disclaimers? We don't need no stinking disclaimers!!!