wjc@XN.LL.MIT.EDU (William J. Chiarchiaro) (04/07/88)
I am contemplating purchasing a DCJ11-AC chip set from DEC. This is the chip set that is the heart of the various KDJ11 cpu cards, such as the 11/53, 11/73, 11/83, and 11/84. I would like to build my own Q-bus cpu card around the chip set. The card would probably be quite simple: no cache, no floating-point accelerator, no boot ROM, and no serial lines. Has anyone else undertaken a project like this? I have ordered a copy of the DCJ11 Microprocessor User's Guide, but I would like to hear about anyone's hands-on experiences. When I pay $473.00 for a chip, I don't want to blow it away on the first power-up. Thanks, Bill wjc@xn.ll.mit.edu
frank@ritcsh.UUCP (Frank Giuffrida) (04/10/88)
In article <952@xn.LL.MIT.EDU> wjc@XN.LL.MIT.EDU (William J. Chiarchiaro) writes: > Stuff deleted..... >Has anyone else undertaken a project like this? I have ordered a >copy of the DCJ11 Microprocessor User's Guide, but I would like to >hear about anyone's hands-on experiences. When I pay $473.00 for a >chip, I don't want to blow it away on the first power-up. > >Thanks, >Bill >wjc@xn.ll.mit.edu About four years ago I built a J11 based system for the Unibus. At that time the chip was just introduced and cost $450.00. I share your feelings about spending lots of money for the chip and then blowing it up. But, I have put that poor chip through lots of pain, and it still continued to work. The DCJ11 Microprocessor User Guide is a must. DEC really did a good job preparing that manual. The J11 itself is quite simple for what you want to do with it. Just remember, tie off all unused inputs, this burnt me for a few days. When I was done with the entire design and debug, I was able to run BSD 2.9 with TCP/IP enhancements on the processor with no problems. The final system had 2 Mb memory, Unibus Map, 40 serial ports, RK07 and TS11 drive controllers. The system supported a load of 20 users running BSD 2.9 with no problems. I had no real problems with the processor or documentation. The manual is correct for the most part. Just beaware that the J11, as well as some other DEC lsi11 processors, do handle some pdp11 instructions in a strange way. In the back of the J11 Users Guide, there is a list of differences between the different pdp11 processors, its worth giving it the once over. Any questions, drop me a note and GOOD LUCK, have fun, I did. ------------------------------------------------------------------------------- Frank Giuffrida uucp: uunet!ccicpg!cci632!ritcsh!frank Computer Science House at&t: 716 475-3305 Advanced Research Group Rochester Institute of Technology