12 Apr
2021
12 Apr
'21
10:43 p.m.
When I was a DEC OEM we used RT-11 and LDA format to load our custom ?OS?. It was my
first real project as a system developer. Made good money in those days... ?
-Steve Davidson
SF:iP1
On Apr 12, 2021, at 16:17, Paul Koning <paulkoning
at comcast.net> wrote:
?
On Apr 12, 2021, at 4:09 PM, Johnny Billquist
<bqt at softjar.se> wrote:
Right.
When someone talks about the paper tape system, and absolute loader format, it is without
any operating system underneath. It's just bare metal. And the absolute loader is just
a simple format that can be read by a small program that you have in memory. It's only
purpose is to read in a paper tape with the binary on it, and start that.
So there are no system dependecies, there are no addressing issues. It's just actual
bytes that will be written to specific addresses in memory, and then a jump to an address,
and off it goes.
Johnny
BTW, SimH can load abs loader format files directly (with the "load" command).
So you don't even need to feed it the abs loader to execute such programs.
paul