6. Videos

In my opinion, expressive videos can mediate much more than any documentation. On my homepage here, You will find some videos available in mpg-format. All videos were loaded to YOUTUBE under my channel names PDP11GY in 2008.

6.1 Info

My videos are splited in 2 categories. First 2 videos demonstrate the technology how prototyping was realized at this point in time, 1984-1992. Both System were restored 2007and are now up and runnig again. The other videos show a special and very rare restored DEC PDP-11/23, timeframe 1983-1987. Restored 2008 and also up and running again. That's nostalgia! ... and nothing more.

VIDEO #1: My pride and joy is to have the worldwide fastest PDP-11, timeframe 1984-1985 still up and running. With other words: A Single-Board-Computer ( SBC ), prototype, wire-wrap technology, which is able to execute PDP-11 code fastest. I was a happy DEC employee 1977 to 1993. Primary, I enjoyed the "Ken Ohlsen" area but I lost all my connection to the US engineering people. For me, one reason to use this channel, is to get in contact with some (ex DEC) people to share information.

VIDEO #2: My personal goal was to design a Computer for a 3 axis CNC machine. With reference to Video #1, the J-11 chip was to expensive for me and I decided to use the Motorola MC68000 CPU with a relativ cost-effective development System, the ATARI MEGA-ST.

Video #3: Restored DEC PDP-11/23. Special design with a Q-BUS - CTI-Bus converter.The entire design and engineering was done by myself. The broken power-supply was replaced by a standard PC power supply.

Video #4: Programing example, running RT-11 with BASIC programing language and MACRO-11 assembler interface on the restored PDP-11/23.

Video #5: System Backup Vintage Computer via Kermit program. Helpful for all Vintage Computer enthusiasts . In this example : completely system backup of a PDP-11/23 running RT-11 from 1987

Video #6: Year 2000 problem/symptom with DEC RT-11 Version V05.04 from 1987. Reproduced 2009 with funny result if no precautions ( patch ) is implemented.


6.2 Links

VIDEO #1 : Prototyp PDP-11 Single-Board Computer ( SBC ), 1985-1986. One of the fastest PDP-11 and may be the fastest one worldwide. Please note: Fast in this case means relatedto the year ~1985. The whole design is in wire-wrap technology. This video should show you the technology how prototyping was realized at this point in time. System was restored2007 and is now up and runnig again. Of course, we can't compare this computer with a realPDP-11 because a real PDP-11 did have much more dependences. Anyway, this Computer works as designed: Fast ! Same clock Speed, same J-11 chip compared to: 11/73:47% faster, 11/83:43% faster. This feature was optained by using very fast static RAM'S and a special logic, which did provide the J-11 CPU the illusion to run always in Cache mode. Anyway, the PDP-11 time is over and now it's just a souvenir with a lot of nostalgia.Background: I was a happy DEC employee 1977 to 1993. Primary, I enjoyed the "Ken Ohlsen" area but I lost all my connection to the US engineering people. I use to channel and hope to get in contact with some people to share information. I appreciate every comment/concern.

Via Windows Media Player ( Standard ) , download: Video-#1

VIDEO #2: Prototyp SBC( Single-Board-Computer ), Wire-Wrap technology, 1988-1992, based on a MOTOROLA MC68000 CPU running at 8Mhrz.Application: 3 axis controlled CNC machine. The MICRO Monitor running in 2 UV-ROM's was written by myself and was able to provide Multi-Tasking ( real-time ) with job context switching. Also , some of ATARI BIOS routines were emulated. I used a ATARI Mega-ST Computer with GFA Basic and/or Mark Wiliams C for Software development purpose. The compiled programs were downloaded to this SB Computer and could be executed remotely.This video should show you the technology how prototyping was realized at this point in time. I also want to show you with this video how extremly changed the chip technology in the timeframe about ~1990. At least , you will find a demo running the final applcation, a 3 axis controlled CNC machine. certainly , this was realized with the final version of a MC68000 based computer in the year 1993.

Via Windows Media Player ( Standard ) , download: Video-#2

Video #3: Restored DEC PDP-11/23, 1983-1988. The purpose of this system was software development running under RT-11, for example: DCJ-11 based Single Board Computer, see my Video #1. It is a very special, rare and unique design based on a Q_BUS/CTI-BUS converter. A lucky change was the reason to get a RD50,= 5Myte hard disk with attached controller board. I designed this Bus-Converter, wrote the the boot code, the format und (scope-loop) test programs and at least a RT-11 device driver. ( RH.MAC ). I was very surprised that my design as well the RD50 hard disk is still running without any problems after more than 20 years. The only big problem I got was the power supply with only 20 min uptime. I was able to replace via a standard PC 350W power supply ... but with a lot of barriers.All details, you will find in the video. The only remaining problem is the RX02 environment. I think, the problem is most likely related to these more than 20 years old floppy media. On the other site, I always get Hard Errors reflecting to a broken floppy drive or a faulty logic. Read operation works fine but any write operation results in a unusable Floppy media

Video #4 : Restored PDP-11/23 from 1983-1987, up and running again. This video shows the BASIC programming language environment under RT-11 by writting a simple BASIC program. Additional the PDP-11 Assembler, MACRO-11 interface is visualized. In this example, you will find assembler Routines to control a CNC machine which will be included in the RT-11 BASIC interpreter via a rebuilt with the RT-11 Link program.

Video #5 : My recommendation to all Vintage Computer enthusiasts: Vintage Computer Date Backup may be become very importend. Computer oldie don't have interfaces based on current used technology like USB or network connection --BUT-- all have a serial console interface. Using the KERMIT program, available on most of all computer platforms, is a very good way to make a full data/system backup. In this example, I used the KERMIT program to create a full RT-11 system backup on W-XP. The KERMIT program I used on W-XP is the try & buy K-95 from columbia university. ( I could 't buy this software until now, because the link to the URL is not working ) This video illustrates all necessary steps to get full system backup from a 5Mbyte RD50 saved on a flsh ram memory, usage only ~4% !

Video #6 : Year 2000 problem/symptom with DEC RT-11 Version V05.04. Symptom reproduced @ MAR-09 running RT-11 Version V05.04, XM-monitor on a restored PDP-11/23 from 1987. Result: Invalid system-date, beginning in the year 2000. System is no loger able to handle creation/writing a file. --- Maybe , there is patch available. I don't know.