[Simh] Looking for a milestone

[Paul Koning]

> On Oct 17, 2016, at 1:42 PM, Clem Cole <clemc at ccc.com> wrote:
> 
> 
> On Mon, Oct 17, 2016 at 12:35 PM, Paul Koning <paulkoning at comcast.net> wrote:
> That doesn't excuse sloppy work.
> 
> ​Agreed - and you will rarely see me defend Seymour.   His systems were fast, but they were not programmer friendly in any way IMO.  Heck the man never had an assembler - he did not think it was needed, he used programmed in octal.
> 
> As I said, close enough for government work seemed to be his mantra; and as long as the US National Labs kept buying from him, clearly he was getting feedback that was an ok way to design.
> 
> Then again our own old employer, DEC took a long time to get around to using an IEEE FP scheme. While DEC was much better at arithmetic than CDC/Cray ever was, it was not until the PMAX and Alpha that DEC started to support IEEE.​  My old friend and colleague Bob Hanek (whom I used to joke as the Mr. Floating Point), once said to me at lunch, he thought trying to get correct results from the Vax FP unit made him lose his hair.  Note that Bob was hardly a great fan of IEEE either, he can regale you with stories of issues with it also.  As I an OS guy, I would smile and just say, I'll thankfully leave that you guys in the compiler and runtime.

While IEEE is a good design, it clearly is not the only possible good design.  I remember that DEC had a math algorithms team that specifically focused on correct (last bit accurate) algorithms for all the various math functions.  I forgot the name of the leader of that group; first name Mary.  It may be that they couldn't make that work with pre-IEEE DEC float, but I don't know.  I tended to avoid floating point.  Heck, I rarely used signed integers...

I still remember chatting with a former classmate who at DEC one late night was busy testing packed decimal exponentiation algorithms.  I asked "why the #$* do you need those?"  He replied: for compound interest in COBOL programs.  Oh yes... Duh...

	paul