25 Jun
2002
25 Jun
'02
5:26 p.m.
On Mon, Jun 24, 2002 at 08:11:43PM +0000, Joe wrote:
At 02:58 AM 6/24/02 -0700, you wrote:
ISIS takes up 12K not including the CLI. I read that the first versions
of CP/M took up 8K (which I guess would include the CCP). Later versions
reduced that by bank-switching the BIOS.
ISIS also requires extra buffers for various reasons (line-edited files
vs. not, disk files vs. not, files used by system calls). Each buffer
is 128 bytes. I remember CP/M FCBs as being smaller but I could be wrong.
Admittedly ISIS machines have at least 32K, maybe 64K, so a 32K ISIS system
would have more free memory (20K or so) than a 16K CP/M system (8K or so).
-- Derek
Since I've been curious about ISIS for some
time, I was glad to finally
borrow a copy of the _ISIS-II System User's Guide_. Comparing ISIS to
CP/M is quite instructive. I already knew that CP/M has a few design
flaws which ISIS lacks.
On the other hand, I was surprised at how much
memory ISIS takes up.
What do you mean? I'm only running 32k on two of my systems and they work just
fine. I consider that pretty good for a non-ROM based OS.