mikes@iuvax.cs.indiana.edu (Michael Squires) (11/10/90)
I posted a note some time ago about using a BSI 486/25 as a portable UNIX 386 box. The only limitation I've run into so far is that the Adaptec 1542B controller runs fine with a max 8MB DMA transfer rate under UNIX but crashes systematically under DOS. It runs OK at 5MB and the next speed up. The disk subsystem (1542B + Micropolis 345MB SCSI) is a little slow. A 386/20/cache/Miniscribe 660MB ESDI/WD1007V uncompresses a 750K file in 40.5 secs (21.3 user, 5.5 sys) while the 486/25 does the same file in 1:10 (27.4 user, 5.5 sys). This is with DMA at 8MB/sec. As I run DOS usually from ODT-DOS (DOS Merge 386) this is so far not a problem but it suggests that the motherboard is not the best. If one is building a new one you might look at the MicroWay 486 motherboard, which should fit. The 3C503 does not seem to work properly (generates spurious entry for Arnet serial card) and crashes TCP/IP regularly; the WD8003E works fine (set at IRQ 2, I/O 380, mem at D0000). -- Mike Squires (mikes@iuvax.cs.indiana.edu) 812 855 3974 (w) 812 333 6564 (h) mikes@iuvax.cs.indiana.edu 546 N Park Ridge Rd., Bloomington, IN 47408 Under construction: mikes@sir-alan@cica.indiana.edu