Mike is somewhat right. You are required to recompile your "PCDOS" programs with gccmvs to produce S/370 code.
If the PC had used the S/370 instruction set instead of the 8086 instruction set, what would you expect PCDOS to look like? This is it, basically. Or you can run z/PDOS-generic standalone. It's the same application executables being run. gccmvs etc. In the same way that z/OS and z/VSE use different executables, z/PDOS-generic is another OS. But "inspired" by PCDOS. BFN. Paul. On Thu, 7 Aug 2025 14:06:03 -0400, Phil Smith III <[email protected]> wrote: >No, he said it's not emulation or a VM. Something is doing some translation. >The language isn't the point... > >-----Original Message----- >From: IBM Mainframe Discussion List <[email protected]> On Behalf Of >Mike Schwab >Sent: Thursday, August 7, 2025 1:27 PM >To: [email protected] >Subject: Re: z/OS PCDOS > >Its coded in GCC. > >On Thu, Aug 7, 2025 at 12:12 PM Phil Smith III <[email protected]> wrote: > >> So what is translating the x86 opcodes to Z opcodes? >> >> -----Original Message----- >> From: IBM Mainframe Discussion List <[email protected]> On >> Behalf Of Paul Edwards >> Sent: Tuesday, August 5, 2025 9:07 PM >> To: [email protected] >> Subject: Re: z/OS PCDOS >> >> On Tue, 5 Aug 2025 18:08:37 -0400, Phil Smith III <[email protected]> wrote: >> >> >This is...interesting, but what is the goal? Or is it just an >> >interest project? (Nothing wrong with that!) >> > >> >Another "interest project": Way back in 2000, Adam Thornton fired up >> Linux under VM/ESA on a P/390. In Linux, he ran Bochs. In Bochs, he >> ran Windows. In Windows, he ran Exchange. >> > >> >Well, maybe "ran" isn't the right word: more like "crawled". But it >> >DID >> come up. Eventually. On modern hardware, might even be tolerable! >> >> >> I just realized something - you might have the wrong idea of what z/OS >> PCDOS is. This is not emulation. It runs applications natively on z/Arch. >> ie full speed. >> >> The applications are not MVS executables though. They are >> z/PDOS-generic executables. I do happen to use the MVS load module >> format though. But that's not very important because I have my own >> loader, so could have used a different format. And indeed, I intend to >> use PE/COFF format for z/OS Windows. >> >> But once the executable is loaded, regardless of format, it is >> directly executed. There is no emulation. There isn't even a VM (which >> also means that if there are any bugs in your application, it can >> crash z/OS PCDOS, ie the EXEC PGM=BIOS will get a S0C4 or whatever). >> The lack of VM means I don't need privilege. >> >> ie any MVS end user can install this software and have an EBCDIC FAT32 >> system running .exe files at full z/Arch speed. With long filenames >> too (although you can't see that in the "dir" display currently, >> because it has been implemented in a crude manner to focus on important >> technical things). >> >> BFN. Paul. >> >> ---------------------------------------------------------------------- >> For IBM-MAIN subscribe / signoff / archive access instructions, send >> email to [email protected] with the message: INFO IBM-MAIN >> >> ---------------------------------------------------------------------- >> For IBM-MAIN subscribe / signoff / archive access instructions, send >> email to [email protected] with the message: INFO IBM-MAIN >> > > >-- >Mike A Schwab, Springfield IL USA >Where do Forest Rangers go to get away from it all? > >---------------------------------------------------------------------- >For IBM-MAIN subscribe / signoff / archive access instructions, send email to >[email protected] with the message: INFO IBM-MAIN > >---------------------------------------------------------------------- >For IBM-MAIN subscribe / signoff / archive access instructions, >send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
