mcmillan@eosp1.UUCP (John McMillan) (02/03/84)
References: This is a request for additional evidence to support, or contradict, a hypothesis of a firmware or hardware problem in some VAX 780's. We run Unix on Vax 780 machines. At various times I have used machines with and without the "floating point accelerator". There appears to be a correlation that Rogue3.6 AND rogue5.2 are very buggy when running without the floating point accelerator. Effects observed without the hardware include: - Rogue simply dies - Rogue goes into a state requiring a "kill" from another terminal to do anything. - Rogue 5.2 makes a save file when you are killed so you may continue playing. - Rogue5.2 goes into full duplex echo mode (echoes ANY input), and does nothing else. - Rogue 3.6 gets soft memory parity errors, but no other programs do. At this point I suspect that the emulation of floating point instructions, as opposed to their execution in hardware, has some side effects. Since almost all of our other software makes little or no use of floating point, Rogue is the only program to show these effects. I would like to receive comments, especially from people who have used rogue both with and without the FP hardware, but from anyone who knows which way his machine is setup. Please tell me, if you use rogue on a VAX 11/780: - what version of rogue do you use? - what version of UNIX? - does it run reliably, at least in dungeon levels 1-26? - Do you have the floationg point accelerator? Two further notes: (1) If you are interested, VAX firmware in the writable control store (provided by DEC, not UNIX) emulates floating point when the hardware is not present. If there is a problem, it may reside entirely within capabilities provided by DEC, although some kind of interaction with UNIX certainly cannot be ruled out. (2) I am aware that the FP accelerator also affects the operation of 32-bit multiplication. Can anyone give me a lecture on just what it does effect? Are there modules within the Unix Kernel (Berkely 4.1), or in drivers, that would be affected by the presence of the FP accelerator? Please respond to: - Toby Robison allegra!eosp1!robison decvax!ittvax!eosp1!robison princeton!eosp1!robison (NOTE! NOT McMillan; Robison.) I will summarize responses.