UC386 (PDOS) vlog
Posted: Mon Apr 17, 2023 3:02 pm
Yesterday I got two important things working on PDOS/386.
1. The infrastructure is good enough to do the BIOS
call to retrieve memory above 64 MB, which uses 32-bit
registers, something I didn't expect in the original design.
2. Serial port is now working on real hardware for receive
as well as send.
So I am now going to cut a new distribution and use a
laptop with a serial port and I will use just the internal
hard disk instead of effectively cheating with USB HDDs
where in 1980s terms I would have had to take the HDD
out of the machine and into someone else's in order to
transfer data.
And I am only going to allow public domain material onto
the laptop (basically UC386). And I am going to start with
a floppy disk image on a CDROM.
As far as I know, everything is in place. I will be able to
write code on my public domain machine, but if I want to
write outside of the limits of SubC I will need to pay a
price by transferring to the full PDOS/386 to get it
compiled "remotely".
I am videoing what I am up to near the end of http://pdos.org
Interestingly I hit a 2 GB limit - so much for everything being
64-bit, when I tried to upload my nearly 4 GB video. So the
second video needs to be reassembled (with copy /b or
equivalent).
BFN. Paul.
1. The infrastructure is good enough to do the BIOS
call to retrieve memory above 64 MB, which uses 32-bit
registers, something I didn't expect in the original design.
2. Serial port is now working on real hardware for receive
as well as send.
So I am now going to cut a new distribution and use a
laptop with a serial port and I will use just the internal
hard disk instead of effectively cheating with USB HDDs
where in 1980s terms I would have had to take the HDD
out of the machine and into someone else's in order to
transfer data.
And I am only going to allow public domain material onto
the laptop (basically UC386). And I am going to start with
a floppy disk image on a CDROM.
As far as I know, everything is in place. I will be able to
write code on my public domain machine, but if I want to
write outside of the limits of SubC I will need to pay a
price by transferring to the full PDOS/386 to get it
compiled "remotely".
I am videoing what I am up to near the end of http://pdos.org
Interestingly I hit a 2 GB limit - so much for everything being
64-bit, when I tried to upload my nearly 4 GB video. So the
second video needs to be reassembled (with copy /b or
equivalent).
BFN. Paul.