z/PDOS-generic

[kerravon]

I have mentioned PDOS-generic here before.

And I think I have mentioned z/PDOS too - for the mainframe.

Now after 35+ years of wondering, I have my first EBCDIC FAT32 disk and z/PDOS-generic (search that on https://pdos.org and get zpg.zip) operating system for the IBM mainframe.

There aren't a lot of features currently as it only just started working a couple of hours ago - but you can do "dir" and "type". Don't use a 3270 terminal. If you are using standard Hercules instead of Hercules/380 you will need to type "tap1c1: -c tap1c2: fba1b1:" at the first prompt (from the pseudo-bios). Because I created the file (using the "copy" command) and the destination file was lowercase, the "test.txt" is actually a long filename, so you see what looks like a rogue "t" in the directory listing - but that is expected due to the crude algorithm (PDOS-generic is sort of a rewrite, so isn't as sophisticated as PDOS/386). And the first "PDOS" you see is actually a volume label, also expected.

Note that the mainframe is unique as far as I know in that people actually WANT to run under emulation to make use of cheaper hardware, but IBM refuses to sell z/OS (the operating system) for use on such machines. This means they are effectively vacating that market. So there might be an opportunity here for hobbyists.

My C90 programs have all worked fine out of the box so far. I hope that I can get my toolchain operational on the mainframe now (ie self-hosting), as it should theoretically work if the code in the toolchain (gcc370 - a fork of gcc 3.2.3) really is C90-compliant.

[iansjack]

Linux runs on Z Series machines, so I'm not sure the market is completely empty of usable OSs for these computers.

But, build a better mousetrap, and the world will beat a path to your door.

[kerravon]

Linux runs on Z Series machines, so I'm not sure the market is completely empty of usable OSs for these computers.

But, build a better mousetrap, and the world will beat a path to your door.

That's ASCII. z/OS is EBCDIC. As is z/PDOS and z/PDOS-generic

If you're willing to convert all your data to ASCII, you probably wouldn't be on a mainframe in the first place.