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Whats was the pdp8 and pdp11 used for when they were new?
- Thread starter NicolasF
- Start date
Many were used in schools or universities. In 9th grade we had dial up access via teletype to the local community colleges pdp-8.
It was tons of fun and what got me interested in computers back in 1970. Later in college I we had a pdp-11/34 in the Comp Sci
dept and then a Vax 11/780. Telephone companies used many pdp-8s. There must be tons of source code out there.
It was tons of fun and what got me interested in computers back in 1970. Later in college I we had a pdp-11/34 in the Comp Sci
dept and then a Vax 11/780. Telephone companies used many pdp-8s. There must be tons of source code out there.
AK6DN
Veteran Member
HoJoPo
Veteran Member
Weren't a lot of PDP-8's used in fast food for the registers / ordering system? McD's or BK if I remember right...
jlang
Experienced Member
I worked on an 8 in the 70's. it was used for taking bets, calculating odds and updating the "tote" board.
I've seen lots of stories that pdp-11's are still running nuclear power plants. Given the approval process for that code I'm going to accept that as true.
I've seen lots of stories that pdp-11's are still running nuclear power plants. Given the approval process for that code I'm going to accept that as true.
kgober
Veteran Member
When the PDP-11 was brand new some folks at Bell Labs bought one under the guise of building a word processing system for typing up patent applications. We know that system today as "Unix". PDP-11 source code for v5, v6 and v7 is readily available.
Qbus
Veteran Member
In addition to the ability to use it as a platform for running compiled higher languages like Basic the PDP-8 and the PDP-11 were also ideal platforms for machine control with a simple and easy to use operating system. In some ways something like the Basic Stamps or the Raspberry Pi of today.
They found their way in to all types of scientific, educational and industrial applications. Along with systems like the Data General Nova they were some of the first small systems available. Before the PDP-8 systems were huge and expensive but that system pointed the way of things to come.
They found their way in to all types of scientific, educational and industrial applications. Along with systems like the Data General Nova they were some of the first small systems available. Before the PDP-8 systems were huge and expensive but that system pointed the way of things to come.
lowen
Veteran Member
I had a PDP-8 years ago that was used for controlling a spherical photometer for a manufacturer of lighting systems. Seems a good match to the capabilities to use for machine control.
PDP-11's saw a great deal of use as machine controllers for a number of reasons, the most important of which was the ability to do hard-realtime control. I've seen several at this point, including an 11/60 that was used to control a specialized scanner that was built to scan glass photographic plates such as produced by telescopes prior to advent of the CCD astronomical imager.
11/23's were very popular for this usage, since they were fast enough yet relatively inexpensive enough for this task. Although I did see one setup of two scanners, based on Perkin-Elmer PDS 2020 microdensitometers, that used VAXstations, and interfaced to the realtime hardware's subprocessors via a SCSI-connected CAMAC crate. The realtime positioner servo was an HP laser interferometer using several 68020s to do the realtime job, positioning the scanning spot to a precision of 63nm. Hardware-clocked FIFOs produced the position-stamped samples, since the 90MHz VS4000 was simply neither fast enough nor realtime enough running VMS to handle it.
11's also got a lot of usage for telescope controllers, again mostly thanks to the hard-realtime capabilities but also due to the great language support of the day on RT11 and RSX11, mostly FORTRAN for scientific uses but later on C took a foothold. Much astronomical software used professionally (such as IRAF) still has a significant FORTRAN heritage.
Today's closest equivalent wouldn't be the RasPI or similar Linux SBCs, but the ATMega328-series SBC's (aka Arduino), which have similar speeds to the various PDP-11's (ATMega 328 SBC's typically clock at 14.5MHz or thereabouts and are quite efficient; high-end PDP-11's such as the 11/93 clock in the same basic neighborhood for the microcycle timing (18MHz) which yields an effective clock (for a direct comparison) of 4.5MHz. The 11 being 16-bit versus the ATMega being 8-bit can make the 11 a bit faster clock-for-clock, but I personally would find a direct comparison (maybe the PI benchmark referenced in the thread at http://www.vcfed.org/forum/showthread.php?69070-VAX-7000-640-CPU-frequency would be interesting). I/O robustness is totally irrelevant to machine control purposes, for the most part, so even though the 11's can likely run rings around the ATMega328 boards in terms of disk I/O etc it just doesn't matter for that application.
RasPI and similar SBCs aren't really built to be hard-realtime, although there are exceptions.
PDP-11's saw a great deal of use as machine controllers for a number of reasons, the most important of which was the ability to do hard-realtime control. I've seen several at this point, including an 11/60 that was used to control a specialized scanner that was built to scan glass photographic plates such as produced by telescopes prior to advent of the CCD astronomical imager.
11/23's were very popular for this usage, since they were fast enough yet relatively inexpensive enough for this task. Although I did see one setup of two scanners, based on Perkin-Elmer PDS 2020 microdensitometers, that used VAXstations, and interfaced to the realtime hardware's subprocessors via a SCSI-connected CAMAC crate. The realtime positioner servo was an HP laser interferometer using several 68020s to do the realtime job, positioning the scanning spot to a precision of 63nm. Hardware-clocked FIFOs produced the position-stamped samples, since the 90MHz VS4000 was simply neither fast enough nor realtime enough running VMS to handle it.
11's also got a lot of usage for telescope controllers, again mostly thanks to the hard-realtime capabilities but also due to the great language support of the day on RT11 and RSX11, mostly FORTRAN for scientific uses but later on C took a foothold. Much astronomical software used professionally (such as IRAF) still has a significant FORTRAN heritage.
Today's closest equivalent wouldn't be the RasPI or similar Linux SBCs, but the ATMega328-series SBC's (aka Arduino), which have similar speeds to the various PDP-11's (ATMega 328 SBC's typically clock at 14.5MHz or thereabouts and are quite efficient; high-end PDP-11's such as the 11/93 clock in the same basic neighborhood for the microcycle timing (18MHz) which yields an effective clock (for a direct comparison) of 4.5MHz. The 11 being 16-bit versus the ATMega being 8-bit can make the 11 a bit faster clock-for-clock, but I personally would find a direct comparison (maybe the PI benchmark referenced in the thread at http://www.vcfed.org/forum/showthread.php?69070-VAX-7000-640-CPU-frequency would be interesting). I/O robustness is totally irrelevant to machine control purposes, for the most part, so even though the 11's can likely run rings around the ATMega328 boards in terms of disk I/O etc it just doesn't matter for that application.
RasPI and similar SBCs aren't really built to be hard-realtime, although there are exceptions.
dfnr2
Experienced Member
I have a PDP-8/e that was used to control stitching machines for embroidery patterns on cowboy boots. The gentleman who sold it to me said that he had been in the business since 1972, and only then was phasing out support for the PDP 8/m machines (like the one I bought), but that he was still supporting 8/a-based setups in Canada and India. I visited his shop in Burleson, TX to pick up the machine, and saw several DEC machines set up as dedicated controllers, and a bunch of stitching machines. That was 3 or 4 years ago. He also had a PDP-11 setup running software for more complex embroidery patterns.
In what used to be called "The Bell System", PDP11's were extensively used in back office functions. Most ran some variant of unix that was developed as a more or less spare time project by Thompson, Ritchie, and others working at Bell Labs as was already mentioned above. The MMOC I worked in for a few years had literally hundreds in service: 11/70's running COSMOS or TIRKS, 11/23+'s running RMAS and RCA, and the 12 11/70's I worked with supporting SCCS. In addition, each SCC had a couple of 11/23's as control consoles for alternate access to the Central Offices they supported when primary systems were down for maintenance or backup.
Mike_Z
Veteran Member
My PDP8E ran a Kearny and Trecker milling machine. You could program it via Mylar (paper) tape. Basically, the computer would control the x and y axis of a large table and the z axis of a rotating chuck. The z axis was also able to choose from 12 different tools. Once programmed, all you had to do was mount a chunk of steel on the table, zero the tool onto a specific corner of the steel and let the machine go and a finished part would eventually be made.
The front half of the PDP8E card cage was DEC cards and the back half were K&T cards. There were two 12 bit I/O cards that were multiplexed for keeping track of where the tool and table were, speeds of the tool, which tool was selected, etc.
The machine tool was scrapped. I just happened to be in the shop the day prior to the machine being sent out the door. I was allowed to take the PDP8E, the REMEX paper tape unit and a box full of prints and extra parts. Mike
The front half of the PDP8E card cage was DEC cards and the back half were K&T cards. There were two 12 bit I/O cards that were multiplexed for keeping track of where the tool and table were, speeds of the tool, which tool was selected, etc.
The machine tool was scrapped. I just happened to be in the shop the day prior to the machine being sent out the door. I was allowed to take the PDP8E, the REMEX paper tape unit and a box full of prints and extra parts. Mike
g4ugm
Veteran Member
Pretty much everything. I think you would be hard to find a use that they were not put to. Certainly that list would probably be much smaller.
DEC started out making logic boards that could be used to build computers
https://en.wikipedia.org/wiki/History_of_Digital_Equipment_Corporation
so knew the value of custom systems, and unlike most computer manufacturers at the time, were open to users "hacking" their machines.
Then they really were the first computers with a BUS with a publicly defined interface. So the later PDP-8s had OMNIBUS, early PDP-11 UNIBUS and later 11's Q-BUS.
This meant you could use them for all sorts of things, and whilst they were expensive they were affordable..
Dr. Dave Clark used a PDP-8 for collecting medical data in real time at Manchester Medical School. He got it to behave like a tape drive and connected it to an IBM7090 that he scrounged from GCHQ (UK Spy agency) when they upgraded.
http://www.dcglug.org.uk/archive-Nov00-May01/msg00245.html
Newcastle University used them to build their early network and for a time had an LSI-11 connected to a train set.
http://history.cs.ncl.ac.uk/anniversaries/40th/webbook/trainset/index.html
In the UK the scientific research community must have brought hundreds, actually probably a couple of thousand for use in collecting and re-formating scientific data. Here are some used at the Daresbury laboratory where they had a small particle accelerator. At the top there is a UNIBUS PDP-11 connected to a CAMAC crate (CAMAC was another standard BUS)
http://tardis.dl.ac.uk/computing_history/pdp-1105.html
In the UK Barclays Bank had one in each branch to connect terminals back to the Mainframe and provide branch automation....
So I don't think there was an area where computers could be used, where you could not find a PDP-8 or PDP-11...
DEC started out making logic boards that could be used to build computers
https://en.wikipedia.org/wiki/History_of_Digital_Equipment_Corporation
so knew the value of custom systems, and unlike most computer manufacturers at the time, were open to users "hacking" their machines.
Then they really were the first computers with a BUS with a publicly defined interface. So the later PDP-8s had OMNIBUS, early PDP-11 UNIBUS and later 11's Q-BUS.
This meant you could use them for all sorts of things, and whilst they were expensive they were affordable..
Dr. Dave Clark used a PDP-8 for collecting medical data in real time at Manchester Medical School. He got it to behave like a tape drive and connected it to an IBM7090 that he scrounged from GCHQ (UK Spy agency) when they upgraded.
http://www.dcglug.org.uk/archive-Nov00-May01/msg00245.html
Newcastle University used them to build their early network and for a time had an LSI-11 connected to a train set.
http://history.cs.ncl.ac.uk/anniversaries/40th/webbook/trainset/index.html
In the UK the scientific research community must have brought hundreds, actually probably a couple of thousand for use in collecting and re-formating scientific data. Here are some used at the Daresbury laboratory where they had a small particle accelerator. At the top there is a UNIBUS PDP-11 connected to a CAMAC crate (CAMAC was another standard BUS)
http://tardis.dl.ac.uk/computing_history/pdp-1105.html
In the UK Barclays Bank had one in each branch to connect terminals back to the Mainframe and provide branch automation....
So I don't think there was an area where computers could be used, where you could not find a PDP-8 or PDP-11...
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Gary C
Veteran Member
In the UK we did one system upgrade and it cost so much we havent risked it again
. I know a couple of plants ran Ferranti Argus systems with PDP-11's running as target machinesOur plant was not built with DEC stuff as TMI seemed to put a stop to the supply, so we are still running our Honeywell DPS6 superminis controlling the alarm and data displays. The reactor itself is controlled by 80286 machines in multibus chassis with a propriatry Pibus I/O rack
daver2
10k Member
Of course we have Gary, we are about to upgrade the next in a couple of weeks time...
Just need to engage the right supplier with a decent Contract. Simples...
Dave
Just need to engage the right supplier with a decent Contract. Simples...
Dave
We maintained some 40+ pdp-11 systems at storagetek. Some of the uses: an 11/44 that ran an automated warehouse. 11/70 that controlled robot part deliveries to manufacturing stations. A cluster of 11/34's that did printed circuit board design and layout. an 11/34 that kept records for in-house medical dept. An 11/34 that managed VLSI chip designs. Some general office automation systems. That's about all I can remember from 40 years ago
We also maintained some DG Nova systems, pretty equivalent to pdp-11's, that managed inventory for a major furniture retailer, managed MICR printing for a major check manufacturing company, provided the thinking for one of the first CAT scanners in the US.
I worked for CDC in those days, and CDC pretty much owned the OEM disk drive market in the 70's and early 80's, which got me in to see a wide range of other systems using pdp-11's, nova, hp, prime, and other mini systems which had CDC drives (mostly 9762/9766) hooked to them.
We also maintained some DG Nova systems, pretty equivalent to pdp-11's, that managed inventory for a major furniture retailer, managed MICR printing for a major check manufacturing company, provided the thinking for one of the first CAT scanners in the US.
I worked for CDC in those days, and CDC pretty much owned the OEM disk drive market in the 70's and early 80's, which got me in to see a wide range of other systems using pdp-11's, nova, hp, prime, and other mini systems which had CDC drives (mostly 9762/9766) hooked to them.
I worked for a number of IC design/manufacturing companies. We used pdp8s as test controllers, production control and statistics analysers. Pdp11s were used (as Applicon workstations) in IC physical design. DG Novas also used (as Calma workstations) in IC physical design. Generally Vaxs came to dominate IC analysis/simulation/verification until the rise of Mentor, Cadence and the like but dedicated layout systems persisted on the lower end machines with custom hardware until the rise of the workstation.
At my company I had the chance to operate a PDP-11/44 which was retired in 1999.
The system was used for a "SILO" with a total storage of 32000 paletts. It was running a TOTAL database which was already out of support when I started at that company.
Sad I could not get my hands on it.
The system was used for a "SILO" with a total storage of 32000 paletts. It was running a TOTAL database which was already out of support when I started at that company.
Sad I could not get my hands on it.
silver
Member
Hi. I worked on PDP-11 systems running RSTS/E from 1974 through to the middle of the 1990s. They were used by a large number of commercial companies, ranging from two users to hundeds. Typically they handled order entry, sales, purchases, stock control, wages etc. PDP-11s also ented up in various niches, such as checking slot machines in casinos, where at one stage about 500 PDP-11s were being used.
If you are really interested, I could send you some of my own code, written in BASIC PLUS.
If you are really interested, I could send you some of my own code, written in BASIC PLUS.
My pdp8/e is a decommissioned unit that did duty in a geosynchronous satellite tracking station
that was part of a chain of parabolic antenna stations that spanned the length of the Bering Straight.
Not sure what was the purpose of my pdp while installed there, the last owner who also worked there said they used multiple computers for communications and for controlling the movement of the dish antennas.
He gave me a picture of the inside of the "relay station" as they were pulling the old computers out of the racks during an upgrade, but I went and lost it.