On 31/05/2014 19:42, Tommo H wrote:
I'm late to the party but congratulations from me!
Thank you!
Now we can all more easily word process just like George R.R. Martin.
I think I'd still sooner user a PC these days! ;-)
Presumably you've got, or once had, some real, physical documents?
The original version of Pro-DOS was written before the large amount of reference material now available
on the 'net. Back in 1991 my local reference library had a copy of the
original CP/M 2.2 user manual,
so I photocopied the "System Interface" section and used those photocopies as
my reference material. It
was all I had to go on at the time. I no longer have those photocopied sheets.
Today there is far more
CP/M reference material available, including the original CP/M 2.2 user manual
as a .PDF. As with *all*
of the programs I have ever written it was all trial and error really!
Certainly no formal methods and
no real planning. I just wrote the code as I went along. Something I've
always done and still do!
One website I found useful for technical reference was: http://www.seasip.demon.co.uk/Cpm/index.html
Perhaps the biggest difference between doing this rewrite and writing the original back in 1991 was the
availability of CP/M programs with which to perform system testing. Back in
'91 I relied on CP/M test
programs collected by Wayne Weedon, with many of those arriving on floppy disks
from software libraries
in the US. For this rewrite I had access to the huge "OAK" and "WALNUT CREEK"
archive CDs which are
both freely available on-line. These gave me much more scope for CP/M 2.2
compatibility testing.
It might be worth remembering that Pro-DOS isn't actually CP/M 2.2 but rather my interpretation of it.
For example, it doesn't have separate BIOS/BDOS sections like "real" CP/M and
is pretty much all one
large(ish) program.
These days I imagine it would be far simpler to take the original CP/M 2.2 and get that running on the
SAM. But "cheating" by using other people's code has never been for me.
Perhaps I'm a masochist!
In the future I'll be sticking to games. Far simpler, and no need to write a user manual either! ;-)
Chris.
