[COFF] What Happened to Interdata?

[Paul Winalski]

On 7/27/23, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:

>
> Someone who's familiar with the 360 instruction set should be able to look
> at e.g.:
>
> and see how compatible it is.

Thanks for the pointer.  I took a quick look.  My knowledge of the
S/360 instruction set is very rusty at this point--it's been over 40
years since I programmed in it.

The program status word (PSW) format looks very familiar.  Both
architectures seem to support 24-bit addressing.

Interdata has some data types and instructions for manipulating them
not present in S/360.  Circular lists, for example, and instructions
for CRC calculation.

I didn't see anything about packed or zoned decimal support.

So perhaps an extended subset of S/360.  I'd have to do a side-by-side
comparison between this document and S/360 Principles of Operation to
determine the level of binary program compatibility, if any.  But it
looks like it might be better than the HitchHiker's Guide to the
Galaxy adage:  "almost, but not quite, entirely unlike tea."

-Paul W