[Info-vax] Intel proposal to simplify x86-64

Mon Jun 5 01:05:03 EDT 2023

On Sunday, June 4, 2023 at 7:57:02 AM UTC-4, Neil Rieck wrote:
> What comes around goes around? How many here remember that VAX-11/780 (as well as 750 and 730) could run PDP-11 code natively in compatibility mode? This ended with the release of the 8000 series (I noticed it on our VAX-8550 which was the first machine I worked on after VAX-11) 

The 8600 / 8650 also had full compatibility mode (but the 8600 was originally the VAX-11/790 before being renamed).

Work on the MicroVAX showed that infrequently-used parts of the VAX instruction set could be emulated with minor hardware assists. The same sort of thing was done with the PDP-11 instruction set. Later versions of the VAX RSX layered product implemented PDP-11 emulation for CPUs that didn't have it natively.

TECO was one of the last holdouts of PDP-11 code on VMS. I think  it finally "went native" in VMS 5.0, but it may have been earlier.  TECO seems to be something that gets dragged along and sometimes fixed later. On Alpha, TECO is a VESTed VAX image. On Itanium, it appears to be a TIEd VESTed VAX image: 

ALPHA::$ dir sys$system:teco*.*
Directory SYS$COMMON:[SYSEXE]
TECO32_TV.EXE;1     
Total of 1 file.

ITANIC::$ dir sys$system:teco*.*
Directory SYS$COMMON:[SYSEXE]
TECO32_TV_AV.EXE;1  
Total of 1 file.

Does anyone with a VSI x86 kit have TECO?