Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 07/08/2012 09:22 AM, Johnny Billquist b...@softjar.se wrote: On 2012-07-08 13:58, Michael Bloom wrote: version of TECO, it might be beneficial to make as much use of local Q registers (those with two char names beginning with .), so that you don't unintentionally accumulate data that you no longer need. You could think of them as a TECO equivalent to alloca(). They came after V36. But they are not strictly needed, as you can push down Q-registers yourself if you want to play with them without affecting someone else. The whole point is avoiding the need to push Q-registers. It is all too easy to make a mistake when pushing Q-registers that costs you a lot of debugging time. If you don't push Q regs, you never have to pop them! If you have local Q regs, there is little legitimate use for pushing/popping them other than to rapidly copy both parts of one q-reg to another q-reg (it's a good idea to use q-regs as two member structs, when you can) If you run out of memory, you are always in trouble... That's why defensive coding is especially important with as memory space as TECO has Not sure when and why you'd need 32-bit arithmetic, though... I'm not sure either, since, as I've already admitted, I don't know the HTTP protocol. But I did want to make a suggestion about long arithmetic, just in case HTTP packets _did_ contain 32 bit fields upon which arithmetic might be performed. With a heads up about this, Richard can look for places where this might be needed, and plan accordingly. It's always beneficial to strategize how to deal with problems prior to dealing with them, rather than just jumping in to code, and then figuring out how to handle each bridge as it is encountered. I doubt you'll ever have TECO leak memory. However, you can run out of memory, so cleaning up your Q-registers, especially if you know they might store lots of data, is a good idea. (TECOs memory handling is rather simplistic, not to mention well tested by now, which is why I doubt you have any memory leaks.) Of course, TECO itself is robust, but . . . I was not referring to *TECO* leaking memory, but rather the program running /within/ TECO, which may append to q register space, push q-regs without popping them, or make memory disappear in other ways. If you've ever written a reasonably large TECO program (such as the DECUS 11-737 package that I previously mentioned), you've got a good chance of having experienced trying to debug a TECO memory leak. This is the kind of place where defensive programming really shines. As one of my college profs was known to say The main prerequisite for debugging is ''bugging''. And especially with a language that so resembles line noise as TECO does, avoiding bugging takes care. Dumping out a file is something TECO can do all day long without a problem. You can either do it page by page yourself, or let teco do it. I was assuming that Richard planned to take use of the TECO data manipulation facilities, not just use it as a glorified cat There are pros and cons to both. But neither will cause you any weird memory issues. Yes, it's how you program that determines whether you reclaim memory that's no longer needed, or not. Local Q-regs allow de-allocation to be automatic when you leave a macro, eliminating a source of coding errors that can result in weird memory issues. That was why I made a reference to alloca(), since local q reg's effectively allocate their space on the TECO program's execution stack. With a C program, if you allocate memory within a routine that you subsequently exit without without saving or freeing the allocated space, you get a memory leak, but memory allocated with alloca() is automatically freed. Same thing with Local Q-regs. When you leave the routine they belong to, poof they are gone. michael ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 2012-07-09 17:29, Michael Bloom wrote: On 07/08/2012 09:22 AM, Johnny Billquist b...@softjar.se wrote: On 2012-07-08 13:58, Michael Bloom wrote: version of TECO, it might be beneficial to make as much use of local Q registers (those with two char names beginning with .), so that you don't unintentionally accumulate data that you no longer need. You could think of them as a TECO equivalent to alloca(). They came after V36. But they are not strictly needed, as you can push down Q-registers yourself if you want to play with them without affecting someone else. The whole point is avoiding the need to push Q-registers. It is all too easy to make a mistake when pushing Q-registers that costs you a lot of debugging time. If you don't push Q regs, you never have to pop them! If you have local Q regs, there is little legitimate use for pushing/popping them other than to rapidly copy both parts of one q-reg to another q-reg (it's a good idea to use q-regs as two member structs, when you can) Right. Just pointing out that local Q-registers came after V36, and that there is another solution for the same problem if you happen to be running pre-V40. Having the language help you is a good thing though. I agree. Not sure when and why you'd need 32-bit arithmetic, though... I'm not sure either, since, as I've already admitted, I don't know the HTTP protocol. But I did want to make a suggestion about long arithmetic, just in case HTTP packets _did_ contain 32 bit fields upon which arithmetic might be performed. With a heads up about this, Richard can look for places where this might be needed, and plan accordingly. It's always beneficial to strategize how to deal with problems prior to dealing with them, rather than just jumping in to code, and then figuring out how to handle each bridge as it is encountered. I can't remember seeing anything that really needs 32-bit arithmetic in the protocol. I doubt you'll ever have TECO leak memory. However, you can run out of memory, so cleaning up your Q-registers, especially if you know they might store lots of data, is a good idea. (TECOs memory handling is rather simplistic, not to mention well tested by now, which is why I doubt you have any memory leaks.) Of course, TECO itself is robust, but . . . I was not referring to *TECO* leaking memory, but rather the program running /within/ TECO, which may append to q register space, push q-regs without popping them, or make memory disappear in other ways. If you've ever written a reasonably large TECO program (such as the DECUS 11-737 package that I previously mentioned), you've got a good chance of having experienced trying to debug a TECO memory leak. This is the kind of place where defensive programming really shines. As one of my college profs was known to say The main prerequisite for debugging is ''bugging''. And especially with a language that so resembles line noise as TECO does, avoiding bugging takes care. Leaking memory, to me, implies that it is lost. Just being sloppy and not freeing up memory you have allocated and still keeps track of is not the same as leaking memory. But yes, keeping your memory usage under control is also a good thing. Dumping out a file is something TECO can do all day long without a problem. You can either do it page by page yourself, or let teco do it. I was assuming that Richard planned to take use of the TECO data manipulation facilities, not just use it as a glorified cat Well, the HTTP protocol is almost more or less just a glorified cat... There isn't that much to it, really. Johnny ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
Well, the HTTP protocol is almost more or less just a glorified cat... There isn't that much to it, really. HTTP is more like CRUD (create, read, update, delete) than cat. http://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol#Request_methods http://en.wikipedia.org/wiki/Create,_read,_update_and_delete Watch out for scope creep. I suspect the OP would be happy with GET and HEAD methods. This describes the bulk of PDP-11 webservers that are widely used. Tim. ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 07/07/2012 10:09 AM, Johnny Billquist b...@softjar.se wrote: What is left is actually writing the code, something that seems to get much less attention... Johnny Good point. I had written a message last night which considered this, but did not get around to sending it. It also addressed hardware and OS options, which are now moot, since an 11/03 running RT-11 has all but been chosen. Here it is below, somewhat edited. I've chopped off the tail end, which discussed Unix Teco Unsent Message [ --- snip --- Message headers snipped -- snip -- ] On 07/06/2012 15:05:38 EDT 2012, Richard legalize at xmission.com wrote: In article 4FF6AE2C.6050104 at dslextreme.com, Michael Bloom mabloom at dslextreme.com writes: What aspect of the experiment requires a pdp-11 architecture? Desire. That's a legitimate reason. I do not understand the reason behind it, but if that is a design requirement, so be it. (Although it does not add any technical information that will help us help you). Even so, with the limits you've chosen, here are a few considerations: You will need enough memory to include the TECO executable, the program written in TECO, and the Q-register data storage necessary for your TECO program, all on top of system overhead. If using a late enough version of TECO, it might be beneficial to make as much use of local Q registers (those with two char names beginning with .), so that you don't unintentionally accumulate data that you no longer need. You could think of them as a TECO equivalent to alloca(). They are documented in the V40 manual (dated May 1985), but I don't recall them being present in V36, so I'm not certain when they were introduced. TECO may not work reliably (except as an editor) without maxing out (to the degree permitted on a PDP-11) the process address space. Under RSTS/E, that would mean 48 KB (the remaining 16KB is needed for the TECO run-time system) minus stack space. I do not recall what the exact overhead might be with other DEC OS's. For RT-11, you'll lose 8 Kb space reserved for device registers plus the amount of space RT-11 itself occupies (4K maybe? Anyone remember?), and of course the space needed for the TECO interpreter itself. A rough guess might be 38Kb for TECO (16Kb for instructions, 6Kb for TECO's private data, 4Kb(??) for TECO's stack), RT-11 and I/O space. That's 38Kb already used, leaving 26Kb left for your buffer, your own TECO code, and your code's Q register variables . If you need to do any 32 bit arithmetic, you'll need to write your own 32 bit arithmetic macros. (I'd suggest using 4 bytes of the text portion of a Q-register for storing a 32-bit datum, rather than wasting the int portion of two q registers (for anyone not familiar with Teco, there are 36 2-part Q-registers, data areas which can be used for 36 16-bit variables plus 36 string variables and you can have executable TECO code as the data in the string variables)). Using a late enough version of Teco that also has macro-local Q-registers accessed as (for example) Q.1 or Q.b, instead of Q1 or Qb) will greatly ease that limitation by not limiting you to using just the global Q registers. V36 did not have this feature. At least V39 and V40 do. (as does the Almy Unix TECO version) The maximum buffer size shrank from one TECO release to the next as new features were added. And obviously, the more Q-register space you use for code and data, the smaller the maximum buffer size will be at any given time. As you proceed during coding, it might be a good idea to periodically check for memory leaks to prevent your server from crashing due to being out of space. One way to do this is to check if the number of characters that the buffer can hold shrinks after each EC command. I don't know the HTTP protocol, so I don't know whether there is a maximum response size, but for larger responses, you might need to build part of the response in the text buffer, write it to the output stream, replace the data in the buffer with the next part of the response, write that out, and so on (probably using PW and HK commands after building each part of the response). [ Afterthought: it might be better to first build response header info in the text buffer, use the A command to append the first page of the reply, then write the served file using the EC command or one of it's derivatives. (This approach would reduce the risk of running out of memory). If you need to make modifications to the file data before sending it, or if you need to send a trailer after the data, then you might choose to page through the buffer with P commands before using EC. ] [ --snip --the rest of this message talked about approaches that have already been excluded, so I have snipped it ] ___ Simh mailing list Simh@trailing-edge.com
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 2012-07-08 18:08, Richard wrote: In article 4ff9af5c.6060...@softjar.se, Johnny Billquist b...@softjar.se writes: Ah! I had never noticed that the string building characters for a search were also allowed in the file commands. Thanks. They are allowed in *any* text argument to a command. Not according to the manuals, but I have not checked the source code. The manual says you can use the string building characters for a search in search commands (obviously), and, to quote the manual: String build characters are also permitted inside the string arguments of the O, EB, ER, EW, and EG commands. Missing from that list is: EI, EN, ^A, I, FR, ^U Admittedly, some of these (like I) have other ways of doing the equivalent, but other times you just have to work around it. But it might be that they are allowed in these commands as well, and the manual is just wrong. I don't know... Johnny -- Johnny Billquist || I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
Well, I'd used the word Weakest to describe this aspect of a computer... Without reading any PDP-11 architecture handbook (today), I'd like to claim the initial design, the 11/20, to have the weakest architecture within the PDP-11 family, it was released in 1970. Just as all (almost) PDP:s the customer would order a CPU, and separately order as much or little of memory that was regarded neccesary for every task... 11/20 had a max. of 56 kB (28 kW), as the design has 16 bits of adressing (=64 kB), but 8 kB are reserved for I/O devices. Exactely how little memory that would be enough to run an OS, Teco and an async port, I can't judge, but running an emulator, like SIMH, would alow for testing of this. The 11/20 was sold along with core memory, so a fair core memory card size for the minimum system would be elegant... The instruction set of a PDP-11 was slightly extended with EIS for modells comming just a few years later, as several options (floating point support, commersial calculations support, memory management for 18 or 22 bits of address-space...) But, as Johnny says, the LSI-11, aka PDP11-03, beeing the first LSI-design from DEC, released in 1975 with the new LSI-bus (aka Q-bus) is always remembered as the slowest PDP of all times, even though the architecture might be slightly improved over 11/20! If you would like a running real physical system, the 11/03 would by far be the easier to get hold of, get running, and keep running. The 11/20 would typically need 2 pcs of 19 wide, 72 high racks... For emulation, this is however not an issue! /Göran On 2012-07-06 21:04, Richard wrote: When I say small, I'm referring to computational capacity, not physical dimensions. ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
I would have to concur. I have a physical 11/05. The 11/05 (same CPU as the 11/10) and it is nowhere near as capable as an 11/03. For a while there DEC had a tendency to release two new machines at a time. One would out perform the previous flagship processor, probably not costing too much more. The other would be comparable with the previous flagship processor but at a lower cost. The 11/05 was the similar capability lower cost follow on to the 11/20. Comparing the 11/05 is slower than the 11/03 and lacking a bunch of useful instructions. The 11/05 is totally devoid of any memory management - 64K address space is all you get. You could not configure 64K, of course because of the reserved address space. Mine has 32K, which I suppose is a typical large configuration. Core memory was expensive. I suppose one could have added a 16K board and had 48K but justifying the expense would have been difficult. On 7/7/2012 3:14 AM, Göran Åhling wrote: Well, I'd used the word Weakest to describe this aspect of a computer... Without reading any PDP-11 architecture handbook (today), I'd like to claim the initial design, the 11/20, to have the weakest architecture within the PDP-11 family, it was released in 1970. Just as all (almost) PDP:s the customer would order a CPU, and separately order as much or little of memory that was regarded neccesary for every task... 11/20 had a max. of 56 kB (28 kW), as the design has 16 bits of adressing (=64 kB), but 8 kB are reserved for I/O devices. Exactely how little memory that would be enough to run an OS, Teco and an async port, I can't judge, but running an emulator, like SIMH, would alow for testing of this. The 11/20 was sold along with core memory, so a fair core memory card size for the minimum system would be elegant... The instruction set of a PDP-11 was slightly extended with EIS for modells comming just a few years later, as several options (floating point support, commersial calculations support, memory management for 18 or 22 bits of address-space...) But, as Johnny says, the LSI-11, aka PDP11-03, beeing the first LSI-design from DEC, released in 1975 with the new LSI-bus (aka Q-bus) is always remembered as the slowest PDP of all times, even though the architecture might be slightly improved over 11/20! If you would like a running real physical system, the 11/03 would by far be the easier to get hold of, get running, and keep running. The 11/20 would typically need 2 pcs of 19 wide, 72 high racks... For emulation, this is however not an issue! /Göran On 2012-07-06 21:04, Richard wrote: When I say small, I'm referring to computational capacity, not physical dimensions. ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
I should point out that the LSI-11 does not have EIS in the basic CPU. It's an option you can add, which have both EIS and FIS (the KEV-11, horrible :-) ). The LSI-11 is also 16-bit addresses only. I tried finding any information about the speed of the thing, but failed. But I think it is actually slower than the 11/05... Anyway, unless the OP actually aim to find a real 11/03, I fail to see the point here. An emulated machine will not perform or behave the same from a time point of view anyway, and since I've already pointed out that RT-11 will run on any PDP-11, and TECO runs under RT-11, any machine running RT-11 is essentially equivalent to the smallest (slowest) PDP-11 from a coding point of view. What is left is actually writing the code, something that seems to get much less attention... Johnny On 2012-07-07 15:33, Davis Johnson wrote: I would have to concur. I have a physical 11/05. The 11/05 (same CPU as the 11/10) and it is nowhere near as capable as an 11/03. For a while there DEC had a tendency to release two new machines at a time. One would out perform the previous flagship processor, probably not costing too much more. The other would be comparable with the previous flagship processor but at a lower cost. The 11/05 was the similar capability lower cost follow on to the 11/20. Comparing the 11/05 is slower than the 11/03 and lacking a bunch of useful instructions. The 11/05 is totally devoid of any memory management - 64K address space is all you get. You could not configure 64K, of course because of the reserved address space. Mine has 32K, which I suppose is a typical large configuration. Core memory was expensive. I suppose one could have added a 16K board and had 48K but justifying the expense would have been difficult. On 7/7/2012 3:14 AM, Göran Åhling wrote: Well, I'd used the word Weakest to describe this aspect of a computer... Without reading any PDP-11 architecture handbook (today), I'd like to claim the initial design, the 11/20, to have the weakest architecture within the PDP-11 family, it was released in 1970. Just as all (almost) PDP:s the customer would order a CPU, and separately order as much or little of memory that was regarded neccesary for every task... 11/20 had a max. of 56 kB (28 kW), as the design has 16 bits of adressing (=64 kB), but 8 kB are reserved for I/O devices. Exactely how little memory that would be enough to run an OS, Teco and an async port, I can't judge, but running an emulator, like SIMH, would alow for testing of this. The 11/20 was sold along with core memory, so a fair core memory card size for the minimum system would be elegant... The instruction set of a PDP-11 was slightly extended with EIS for modells comming just a few years later, as several options (floating point support, commersial calculations support, memory management for 18 or 22 bits of address-space...) But, as Johnny says, the LSI-11, aka PDP11-03, beeing the first LSI-design from DEC, released in 1975 with the new LSI-bus (aka Q-bus) is always remembered as the slowest PDP of all times, even though the architecture might be slightly improved over 11/20! If you would like a running real physical system, the 11/03 would by far be the easier to get hold of, get running, and keep running. The 11/20 would typically need 2 pcs of 19 wide, 72 high racks... For emulation, this is however not an issue! /Göran On 2012-07-06 21:04, Richard wrote: When I say small, I'm referring to computational capacity, not physical dimensions. ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh -- Johnny Billquist || I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
In article 4ff86d51.8080...@softjar.se, Johnny Billquist b...@softjar.se writes: Anyway, unless the OP actually aim to find a real 11/03, I fail to see the point here. Well, it so happens that I do have an 11/03, although I wasn't thinking of running this little dog-and-pony show on the actual hardware. I was content with emulating a small SIMH configuration in order to see just how small I could make it. I also have a VT180, and an 11/83, but I haven't ever powered up either of those. What is left is actually writing the code, something that seems to get much less attention... That part I can handle on my own and I've already started looking at it. It's really not that difficult, but requires a few advanced TECO tricks (ER with substituting the contents of a q-register in the text of the filename argument). GET requests are fairly trivial. PUT is possible. DELETE I'm not so sure about, unless EG is supported in the target environment. HEAD is also a problem because there's no way of getting file attributes (modified or created time) directly from TECO. Again, you might be able to hack something together if EG is supported. POST to a TECO macro URL is possible. -- The Direct3D Graphics Pipeline free book http://tinyurl.com/d3d-pipeline The Computer Graphics Museum http://computergraphicsmuseum.org The Terminals Wiki http://terminals.classiccmp.org Legalize Adulthood! (my blog) http://legalizeadulthood.wordpress.com ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 2012-07-07 22:06, Richard wrote: In article 4ff872b4.5000...@softjar.se, Johnny Billquist b...@softjar.se writes: So, an 11/05 or 11/10 it is, if you want the slowest PDP-11. I wasn't thinking slowest so much as minimally configured. I can make any machine slow by putting in a lower speed clock on it. Exactly. So why the requirement? Minimally configured? That's a new one. What does that mean? Not the same as the slowest, I would assume... Johnny -- Johnny Billquist || I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 2012-07-07 23:05, Richard wrote: In article 4ff89f2f.4060...@softjar.se, Johnny Billquist b...@softjar.se writes: That part I can handle on my own and I've already started looking at it. It's really not that difficult, but requires a few advanced TECO tricks (ER with substituting the contents of a q-register in the text of the filename argument). You don't do it like that. You create the command in the main buffer, with all the glory you want. You then store it in a q-register, and then you execute it. That's one way you can do it, but not the only way and the particular trick I'm talking about is irrelevant to what you're describing. Please tell me of another way. I have not realized one yet. (Honestly, always curious to learn new stuff.) I wrote my first TECO programs in 1979, so I already have that covered. :-) Johnny -- Johnny Billquist || I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
11/21 Falcon board, ie KXT11-{AA|AB|BA|CA} is a single-board,
Dual-wide (to use DEC descriptions counting the number of contact
finger groups on the card-edge) for earlier versions, quad-wide for -CA
PDP-11 CPU board with integrated memory and 2 or 3 serial ports. The
last version could have memory up to 64 kB on-board, slightly earlier
version max 48 kB, the first version 4 kB. The OEM computer of those
days - compare it to an ARM or PIC-chip of today. CPU is the T-11 chicp,
ie generation 2 out of 4 integrated generations. Picture of dual-wide
type at: http://www.conticomp.com/item_show.cfm?itemID=157659
BUT: The last fine PDP-11 by DEC was the PDP11-93 CPU. This was built as
a single-card computer, quad-wide Q-bus, integrated memory (2 or 4
MBytes depending on version/price), integrated 8 serial lines,
integrated boot-rom etc. CPU is the J-11, ie generation 4 out of 4
integrated designs.
So, physically, both these are the same, but the later has more of
horsepowers in it's CPU. Both of them would do the job you have
described, the latter would do it eassily...
(All early PDP-11:s were built upon MSI logic, so a CPU would need at
least a few cards, each hex-wide size.)
When it comes to the architecture, The PDP11-20 (with oem name PDP11-15)
was first. This one ha the smallest architecture, with a minimum of
features. To design the smallest PDP-11 emulator, an 11-20 should be
emulated (I think there is an FPGA-code on the net for this CPU). This
one has 16 bits of adress, ie max 64 kB memory.
For OS:es, RT-11 is certainly the smallest of those that were offered
by DEC in the later part of the PDP-11 era. RT-11 can run on most system
configurations, using minimum floppy or TU-58 tape drive as secondary
storage.
The TU-58 tape-drive was connected using one serial port. PC-based
emulators of this 1/4 tape drive exists freely today (using PC with
COM-port).
One small system to copy in config could possibly be a PDT11-150 or a
VT103 aka PDT11-110 and/or PDT11-130. Actual config of these should be
possible to find online...
As for emulations, this coule of today be run in a system not much
larger than a coin...
More information can be read at:
http://hampage.hu/pdp-11/main.html
http://en.wikipedia.org/wiki/PDP-11
and at lots of other fine sites through the net.
/Göran
On 2012-07-05 19:03, Alan Frisbie wrote:
And people who know PDP-11s are asking them self smallest
pdp-11, what is that?
The smallest one I recall was put together by John Crowell,
and was based on an 11/21 Falcon board. My memory is a
bit hazy (hey, it was 30 years ago!), but it had one or two
TU58 drives and ran RT-11 (anyone who knows John would not
be surprised by that). Since it was used for collecting
data in the field, he called it the Field-11.
Somewhere in my archives I have a magazine article about it.
I'm sure there were even smaller ones based on the T-11 chip.
Alan Frisbie
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Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 2012-07-06 21:04, Richard wrote: When I say small, I'm referring to computational capacity, not physical dimensions. Excellent. Now we have something more tangible. I think I already pointed this out, but we might as well repeat it. RT-11 can run on any PDP-11 CPU, including an 11/03, which I think is the computationally weakest model. You'll have a Q-bus. and you can stuff up to 56 Kbyte in there, which is enough for RT-11 and TECO. As you said you'd be happy to have some other machine manage to actual TCP/IP connection, and just have a serial line to the PDP-11, this setup fulfills your requirements for a machine running TECO, as well as probably being the slowest one. However, where you'll find a PDP-11/03 today, I don't know. If you instead plan to use simh, then it's no longer the smallest, by any longshot, and that requirement becomes just plain silly. Johnny -- Johnny Billquist || I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 2012-07-05 07:34, Richard wrote: In article 4ff4dee5@softjar.se, Johnny Billquist b...@softjar.se writes: I'm not totally clear about what smallest mean here. Common sense meaning. PDP-11/70 is bigger than a PDP-11/34. Ok. So, pick the smallest. A VT103 should qualify pretty well, I think. Besides, you mentioned before that having a real TCP/IP was not actually required, and that having another machine do the TCP/IP part, while your PDP-11 just talked over a serial port would be ok. Yes, but it still needs to run TECO and serve files. So obviously it can't be a 4K PDP-11/03, because AFAIK, that can't run TECO. Probably not. But a 28K PDP-11/03 will. Johnny -- Johnny Billquist || I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
Perhaps I'm showing stunning naivete here, but … couldn't you just get all your stuff working (TECO and TCP/IP or whatever you use instead) on a large PDP-11 emulation and then reduce it to the smallest configuration you can find? Or is the experimental approach somehow bad, even though it doesn't cost anything at all in hardware? -- Perhaps people don't believe this, but throughout all of the discussions of entering China our focus has really been what's best for the Chinese people. It's not been about our revenue or profit or whatnot. --Sergey Brin, demonstrating the emptiness of the don't be evil mantra. ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 2012-07-05 18:18, Richard wrote: In article CAGKutLuhRyAk+tNLtDivRX12n4HB=cXGfAJxfkGHZJE_pmav=g...@mail.gmail.com, Michael Richter ttmrich...@gmail.com writes: Perhaps I'm showing stunning naivete here, but ... couldn't you just get all your stuff working (TECO and TCP/IP or whatever you use instead) on a large PDP-11 emulation and then reduce it to the smallest configuration you can find? I think the confusion is that people are assuming that I know everything they know about PDP-11 configurations. I know next to nothing. So when they say something like just use the smallest one, I'm like... WTF does that mean? And people who know PDP-11s are asking them self smallest pdp-11, what is that? So it becomes a circle of WTF questions. :-) Johnny -- Johnny Billquist || I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
And people who know PDP-11s are asking them self smallest pdp-11, what is that? The smallest one I recall was put together by John Crowell, and was based on an 11/21 Falcon board. My memory is a bit hazy (hey, it was 30 years ago!), but it had one or two TU58 drives and ran RT-11 (anyone who knows John would not be surprised by that). Since it was used for collecting data in the field, he called it the Field-11. Somewhere in my archives I have a magazine article about it. I'm sure there were even smaller ones based on the T-11 chip. Alan Frisbie ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 2012-07-04 21:49, Richard wrote: In article 4ff3cdb3.3010...@dslextreme.com, Michael Bloom mabl...@dslextreme.com writes: All you really need is some kind of box that runs TECO and has sockets, right? ...if all I cared about was the TECO part, yeah. But no, that's not all I care about which is why I've been asking about the smallest PDP-11 that could run this setup. Still haven't gotten a suggestion on a particular PDP-11 HW config. I'm not totally clear about what smallest mean here. Smallest how? The physcially smallest actual PDP-11? The smallest memory footprint? The slowest CPU? It's all kindof weird if you're going to run it on an emulated machine anyway. Besides, you mentioned before that having a real TCP/IP was not actually required, and that having another machine do the TCP/IP part, while your PDP-11 just talked over a serial port would be ok. So, that essentially means that all you care about is the TECO part. Have some PDP-11 run an OS, have TECO running on it, and have that whole thing in simh. Have the console port connected to a telnet server on port 80, and all you need to write is your TECO code. Johnny -- Johnny Billquist || I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 2012-07-01 16:29, Richard wrote: In article 4fee0fe0.9050...@softjar.se, Johnny Billquist b...@softjar.se writes: But to prove that it works, you need to do that sooner or later. Once you've solved all the TECO issues, you can look at at machine to run it on. ...which, by the way, noone has suggested a particular SIMH configuration, just PDP-11. Well, RT-11 can run on just about any PDP-11 configuration you can think of. And using simh, you can have it connect the console terminal to a telnet port, so there you go. Just write the TECO macro... Johnny -- Johnny Billquist || I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
In terms of sweet and small, you want Alan Baldwin's TCP/IP for RT-11 implementation. http://shop-pdp.kent.edu/ It has a very nice and sensible TCP/IP application interface and in fact comes with a webserver and other common TCP/IP applications and utilities. ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 6/29/12 10:48 AM, Richard wrote: In article303A17BD5F8FA34DA45EEC245271AC0B251BAEAE@JGEX2K10MBX2.wmata.local, Shoppa, Timtsho...@wmata.com writes: In terms of sweet and small, you want Alan Baldwin's TCP/IP for RT-11 implementation. http://shop-pdp.kent.edu/ Wait... 512K of system memory required? Doesn't sound very small to me for a PDP-11! A complete TCP stack is a memory hog. The ones running on 64k address space micros have almost no buffering. ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 2012-06-29 19:58, Richard wrote: In article 4fedec05.8050...@bitsavers.org, Al Kossow a...@bitsavers.org writes: On 6/29/12 10:48 AM, Richard wrote: In article303a17bd5f8fa34da45eec245271ac0b251ba...@jgex2k10mbx2.wmata.loca l, Shoppa, Timtsho...@wmata.com writes: In terms of sweet and small, you want Alan Baldwin's TCP/IP for RT-11 implementation. http://shop-pdp.kent.edu/ Wait... 512K of system memory required? Doesn't sound very small to me for a PDP-11! A complete TCP stack is a memory hog. The ones running on 64k address space micros have almost no buffering. That's what I figured; I could live with chit-chat over a serial line for the purposes of this crazy experiment. The idea is that TECO is used to process a file that contains HTTP request header and HTTP request body and edits it in-place to replace it with HTTP response header and HTTP response body. The communications part isn't the interesting part of this experiement. The interesting part is the TECO hack. So, setup (or log into) any PDP-11 with TECO. Write your TECO macro that reads and verifies the HTTP request, and makes a response. Done. Johnny ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
On 2012-06-29 20:40, Richard wrote: In article 4fedf01a.9010...@softjar.se, Johnny Billquist b...@softjar.se writes: So, setup (or log into) any PDP-11 with TECO. Write your TECO macro that reads and verifies the HTTP request, and makes a response. Done. Yeah, but not really a functioning system end-to-end. So not done. But to prove that it works, you need to do that sooner or later. Once you've solved all the TECO issues, you can look at at machine to run it on. Johnny -- Johnny Billquist || I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] smallest pdp-11 that can run TECO and sockets(*)?
The kermit system may do what you want: it exists for many historical, and current, platforms, and newer versions support network interconnects as well as the traditional serial line connects. See http://www.columbia.edu/kermit/ http://www.kermitproject.org/ http://en.wikipedia.org/wiki/Kermit_%28protocol%29 --- - Nelson H. F. BeebeTel: +1 801 581 5254 - - University of UtahFAX: +1 801 581 4148 - - Department of Mathematics, 110 LCBInternet e-mail: be...@math.utah.edu - - 155 S 1400 E RM 233 be...@acm.org be...@computer.org - - Salt Lake City, UT 84112-0090, USAURL: http://www.math.utah.edu/~beebe/ - --- ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
