[Simh] Way out idea for simh

[Davis Johnson]

I haven't heard any mention of ANSI labeled tapes as a data format. OS 
support varies, and interpretation of the standard varies perhaps even more.

I never liked them much (I never had good tools for them on my real 
hardware). In theory it should be a reasonable common format.

On 04/21/2016 03:56 AM, Veit, Holger wrote:
> I think this is missing the actual problem. If a simh supported 
> machine has some kind of (paper/magnetic) tape oder disk device, they 
> are almost always physical files on the host system which can be 
> attached/detached by simh console commands. What is in the files, a 
> file system or bit stream or block structure, and what data encoding 
> is used, is entirely depending on the emulated operating system. Since 
> some simh emulators support different operating systems, like 
> RT11/RSX11/Unix7 on a PDP-11, a built-in FTP API (or any other 
> transfer utility, Zmodem, Kermit, etc.) must effectively know what OS 
> is currently running.
>
> Some structures, like Files-11, are well documented, other might not, 
> or not fully. If the data structures used are sufficently known, 
> whether simple or not, one can write host software that converts a 
> user file and extracts or injects it into the expected data structure. 
> There are numerous programs for all kinds of guest operating systems; 
> and I have myself written some as well whenever I need them, but 
> neither are such tools complete or portable, nor are they based on a 
> widely accepted source format.
>
> This leaves the burden to the target operating system to write a 
> conversion tool that takes some input - from whatever source - and 
> converts it into its own native file format. This is probably even 
> more challenging, because unless it is an already supported input 
> source, like a paper-tape reader or an emulated serial line, one needs 
> to write some kind of device driver, or as suggested for RTE/6VM, some 
> custom microcode instruction, to be surrounded by some native 
> assembler or FORTRAN file (which leaves the open question whether this 
> then can be reused in RTE/IVB, RTE-A, MPE etc. without major rewrites).
>
> The Kermit approach appears to be most feasible for the moment, as it 
> actually works through a supported input source, does the necessary 
> conversion, and is anchored in the target operating system where fo 
> which it exists. It should rather be analyzed why it doesn't seem to 
> work on RTE - operating system issue, or simh emulation flaw? I 
> remember having transferred numerous files between the HP1000 and the 
> big VAX in a former life. Surely, certain file types won't work, but 
> text is commonly possible. And for some special cases with IBM iron, 
> there were native EBCDIC converters.
>
> Surely it won't work for very old systems for which no Kermit exists, 
> but then also some other means like an FTP API wont' help either.
>
> The terminal emulation issue that only QCterm might be usable with 
> HP1000 is a different topic, but it is a related general problem: not 
> every system can deal with the lingua franca VT-100/ANSI, and not all 
> terminal emulators work correctly.
>
> Holger
>