Time to cast a wider net, but I'm not a fan of the "throw 58 hashtags at it to see what sticks" shotgun approach, so I'll just ask the handful of #PERQ nuts still around to look to their left, look to their right, and point out the person who might have the PNX sources or documentation I seek. (If it's neither of them, maybe it's YOU! Go get that dusty old box of 8" floppies from the back of that shelf and bust out the Catweasel.)

Because surely someone, somewhere, remembers SERC, the 1980s, Chilton, RAL, ICL Dalkieth, PNX, etc. -- and squirreled away some docs, or diskettes, or even a whole PERQ with *some* information about the "C-Codes" instruction set and virtual C machine architecture of PNX. NMOC? Bletchley Park? Beuller? Anyone? There can't possibly still be concerns about throwing a copy of the sources over the transom 40 years on for research and preservation.

In the meantime, reverse engineering the kernel's microcode debugger is arduous and painstaking. Here's where we're at after a floppy or hard disk boot: both halt in a similar manner, somewhere at or before attempting to tekload the updated Z80 firmware. I'll get there, eventually, through sheer doggedness. But PNX kernel hackers of yore, lurking in #vintagecomputing, long free of ICL's closed-source bloody-mindedness, chime in anytime. :-)

Another release of PERQemu has breached containment. Some interesting and Very Serious Business Applications are bundled with a couple of the new disk images. Check it out at https://github.com/skeezicsb/PERQemu/releases

#PERQ

@stepleton I'm slipping: got it on the third try.

"MEMO

TO: Reddy, Rosen, Verostic, Sowinski
FROM: Hulley
RE: Floppy drive error rate
DATE: 31 May 83

Pradeep and I have spent the past week exploring possible solutions to the high data error rate being experienced during floppy disk use. The problems seem to be centered around the Standard Microsystems FDC9216B floppy data separator.

Review of what we have tried:

ECO number 00482 added a receiver for raw floppy data and changed the pullups on the lines between the drive and the EIO board. This ECO also upgraded the data separator to the 'B' part.

Per SMC's suggestion we tried changing write precompensation to 312 nanoseconds from 250 nanoseconds. Result: error rate increased by a factor of four.

Changed clock on data separator to 8 Mhz crystal oscillator driven to insure that clock duty cycle was not causing any problems."

Unfortunately, the memo does NOT say if/how they actually fixed the problem. 😠 So, uh, not terribly useful after all. Sigh.

#PERQ @fvzappa Bwaaaa ha ha ha ha ha ha!

My son has incredible Craigslist/Ebay-fu, and just picked up an even more ridiculous gaming PC as a graduation present to himself. Naturally, there's only one benchmark I care about, so before he wipes and rebuilds it I snuck PERQemu on there for some fun. :-)

Accent on a 20MHz PERQ is *buttery.*

#introduction

The OG #PERQ Fanatic. Everyone has their kink; mine's an obscure and quirky pile of TTL and broken dreams from the early 1980s. The fantastic plastic RasterOp workstation warped my young brain; 40 years on I'm still enthralled: https://github.com/skeezicsb/PERQemu

Background? Sysadmin and hacker from the time_t when mastodons roamed the earth. Office Space is the unofficial biography of my life and career.

From dotcom optionnaire to aggressively unemployed, I just can't take this world seriously anymore. Here as long as the coffee holds out, still slowly sliding naked down the dull rusty razor of life. Yawp!