Dickson@his-phoenix-multics.arpa (Paul Dickson) (07/12/88)
My friend Kevin and I have been porting Minix to a 186 Single Board
Computer that is designed and sold by Slicer Computers. The hardware
consists of a 186 CPU, the 2681 DUART, and the 1797-2 Floppy Controller
We started the port about 6 weeks ago (we've only been working partial
weekends) and we are now about two week from completion. We've written
the floppy software, a dual port serial tty software, loader software,
plus change the code to use the 186's interrupt controller and DMA
channels.
We got our floppy software running on July 2nd and then starting writing
our interrupt driven tty.c (prior to this, we had all output being done
while the rest of the system waited). Last night we finally got the
interrupt driven output working, although the input doesn't work yet.
Our interrupt driven tty.c is based on the design used by the tty.c that
was distributed for 1.3, but since the behavior of the 2681 is different
from that of the PC's serial chip, we wrote quite a bit of code from
scratch. When we get done, we will have two login serial lines.
We were suprised to discover that Minix 1.3 added entrypoints for each
interrupt vector less than 16, so that a vector number could be
outputted with the kernal panic message. We had done the same thing for
debugging purposes (the Slicer has two interrupt lines that float and
were causing us spurious interrupts. We fixed this by ground the lines).
-Paul Dickson
Phoenix, Az
ARPAnet: Dickson%pco @ BCO-Multics.ARPA