开云体育

I wasn't directly involved in either processor design, but in the late 70's
I worked at a company called Ramtek (long since failed) where they?
had a PAL to flip the memory map (all 64kbytes of it) when an interrupt came in
to switch the processor over from user state to system state.
And in the 80's, a firm called Metheus where they had two 68000 processors
for system and user state, one was always idle and waiting for the flip.
This was before the 68020 came out.

In '89 I spent a year in Japan, part of my job was writing DMA device drivers
to lock down part of main memory and then continuously shovel out a ring buffer
of data to an IO port as fast as possible.? One was on a Sony News Unix box,
all the manuals in Japanese, but fortunately all the technical terms
were English words spelled out phonetically in katakana.
And yes, each bug fix meant an hour or so of compiling the kernel.

I often dreamed of building my own computer from college on,
but never successfully acted on it as Erik did.

In the 90's, all the cheap engineering tools moved to MSWindows, unfortunately.
I was all thumbs until I could install a fake unix command line prompt,
similar to cygwin, percentshell, or minGW.? Tried my best not to muddy my brain?
with that MSWin crap, thankfully there was always somebody to ask when I had
to edit a registry or configure a network connection.

Jerry, KE7ER