test-drb

test-drb@ccmp.vtda.org

101090 discussions

by healyzh＠aracnet.com

I got the Base Set of OpenVMS 7.2 doc's that I ordered today. How disgusting! On the spine, it says "Compaq OpenVMS", and the spines are ALL white, so they aren't colour coded by type. Oddly two of them are the old Digital manuals from the 7.1 release. I don't mind the "Compaq" where the "digital" used to be, it's the "Compaq OpenVMS" I find sick! How egotistical! Oh, well, I've got doc's that match the version I'm running now at least (though the V5 "System Managers Manual" will continue to be the most used manual). Now if the two Cluster manuals that I ordered at the same time would ship, I'd be almost happy. Still need up-to-date DECnet manuals though. Zane (Axiously waiting for the V2 Hobbyist CD's to be ready) | Zane H. Healy | UNIX Systems Adminstrator | | healyzh(a)aracnet.com (primary) | Linux Enthusiast | | healyzh(a)holonet.net (alternate) | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | and Zane's Computer Museum. | | http://www.dragonfire.net/~healyzh/ |

26 years, 8 months

A IIgs keyboard is a?

by PB14＠leicester.ac.uk

On 31 Mar 99 at 18:18, Mike Ford wrote: > M0487 Small, no function or direction keys, and indents on both sides of > the rear where the ADB plugs are. Sorry, no IIgs handy at work to check the part number. However... The M0487 is the model which first shipped with the Mac Classic and LC. It is is the successor to the M0116 which was supplied with the SE series (the M0116 again has no function keys but the frame surrounding the keys is rectangular and generally more conventional in shape). Phil ************************************************************** Phil Beesley -- Computer Officer -- Distributed Systems Suppport University of Leicester Tel (0)116 252-2231 E-Mail pb14(a)le.ac.uk

26 years, 8 months

homemade computer for fun and experience...

by allisonp＠world.std.com

<I seriously doubt, however, that anyone has written an article about <mounting two ISA cards on an S-100 board which occupies only a single card Form factor is of little meaning and actially in many cases pointless. However I'd already done it using 8bit ISA cards and for many it's trivial if DMA is not required. Allison

26 years, 8 months

Probably OT: Copy-Rite duplicating machine

by roblwill＠usaor.net

Hi! I know this is probably off-topic, but I figured that someone here may be able to give me a bit of info on this thing. Today my church gave me this old copy machine (Is mimeograph the proper word for it?). I've figured out how to load the paper and turn it on, but that seems to be all. I put the paper in the one side, drop the loading rollers, push down a lever on the other side, some sort of liquid squirts out of a reservoir onto a roller, the paper gets pulled through, and comes out the other side (the side with the lever) into another tray, and is damp (from whatever squirted on to the roller). On the side where the paper comes out, there's a large aluminum roller with a slot in it. I've seen things like these used in movies (I think), and on that roller is what looks like a piece of carbon paper. If so, how does it work? Now the questions: - What is the liquid in the reservoir? It looks and smells like alcohol (sort of - it's been sitting in there for about 20 years) - What type of ink (if any) would it use, and where would I find this ink? - Where does the thing (document - whatever) go that I would want to copy? I think that's all the questions that I have for now. Please reply to me privately (don't want to take up the list's bandwidth). I'd like to get this thing working, since it's in pretty good shape, appears to function, and still has the original dust cover :) ThAnX, -- -Jason Willgruber (roblwill(a)usaor.net) ICQ#: 1730318 <http://members.tripod.com/general_1>

26 years, 8 months

Lisp, the machine language. Was Re: Hallelujah!

by hhacker＠home.com

>> Consider the instruction set of the x86. The MOV instruction is actually >> implemented as a small sequence of microinstructions. There is, in fact, >> no dedicated series of gates and other electronic aparatus which >> implements the operation of MOV. Instead, it is implemented as a >> series (or sequence) of smaller operations, such as LOAD REGISTER, >> ADD REGISTERS, etc. If you are not familiar with the processes of >> microprogramming, then you should become so. Microprograms are >> not stored in RAM. Instead, they are stored in ROM. > >Microprograms can be stored in RAM. It may not be common to have a 'soft >microcodes' processor (one where the microcode is stored in volatile >memory and loaded when the machine boots), but they exist. I can see 3 >from where I am sitting (2 PERQs and a Xerox Daybreak). > >If you think of a normal machine code instruction, then there are several >steps that have to be performed to execute that instruction and fetch the >next one. You can represent that process either as a collection of random >logic, or as a state machine with one flip-flop per machine state (which >is how the Philips P850 does it), or as a program. The last is >essentially what microcode is. > >> For those who are aware of the operations of the HP 21MX processors, >> these are microprogrammed machines. As it happens, the user of >> such a computer can alter the microprogramming. This is the computer > >In other words the microcode is partially stored in RAM on this machine. > >> Now, it is true that the printed text of the program must be converted to >> the instruction set of the computer but, the process is like this. >> >> "CAR" corresponds to the instruction with byte code 0x01 >> "CDR" corresponds to the instruction with byte code 0x02 >> >> and so on. Of course, the byte values I give are only examples. The >> true translations are not known to me. However, each operator of >> the Lisp language will correspond to a single instruction code of the >> Lisp machine. > > >There is a problem here. The process of programming in Lisp is >essentially defining new functions. So either _all_ of these are stored >in microcode (which would require a very large control store) or more >likely (and I happen to know that the PERQ Spice LISP does it this way), >there are some 'core' functions (like CAR, CDR, CONS, etc) that are >implemented as microcode, and higher level functions, including ones >defined by the user are defined in terms of these (and other higher level >functions). > >In which case, the program that translates a user definition into the >calls to both microcode and 'machine code' functions is pretty similar to >a normal Lisp implementation running on a micro (many of which do not >compile all user input to the machine code of the CPU they happen to run >on). It's dubious whether you call that an interpretter or a compiler, >though. > >-tony > Of course, I over simplified the discussion but, only to get my point across. Sure, it is possible for the microcode to be in RAM. The IBM 370's were just such machines. More than once, while I was an operator of such computers, the service representative came to the site, opened a panel on the operator console, and changed the 5 1/4" floppy disk. By doing so, he changed the microprogram of the computer. This microprogram was loaded each time the computer was powered on. For the x86 however, the microcode is hardcoded into the chip. My wish is for a computer system that provides for dynamically modifiable microcode, so that my self-modifying programs could obtain a new level of self-modifyability! As for the Lisp difficulties, remember, it takes only a few of the basic operators to define the language. All else can be derived from same, and AFAIK is derived from same. So, there is no need to implement derivable functions in microcode. William R. Buckley

26 years, 8 months

microcode, compilers, and supercomputer architecture

by hhacker＠home.com

>Megan wrote: >> well put... I've yet to find a compiler which can produce code which >> could not then be further optimized in some way by a person well >> versed in that machine's architecture... > >Yes, but if you paid attention to the original claim, you would see that >I asserted that it was true for horizontal microcode with large amounts >of data dependency. This is *very* different than trying to compile C >(or Pascal, or Bliss, or whatever) for a typical architecture (which more >closely resembles vertical microcode). > >One of the systems I microcoded had 512 words of control store (of about >72 bits each), and running my microprogram source code through the compiler >produced 514 words of microinstructions. With about two weeks of >concentrated effort, I was able to eventually squeeze out two >microinstructions. Total development time: 6 weeks. > >If I had tried to write all of the microcode in "assembly", it would have taken >me longer to write, and it probably would have been *bigger* on the first >pass. And I still would have had to spend a lot of time on hand optimization. >I think this would have taken at least 12 weeks of development time, although >since I didn't do it that way I'll never know. Your argument, Eric, was that the microcode compiler generated code that is equally as efficient as that you, or someone else, could have constructed by hand. Megan in no way implies the use of assembly code. The microcode compiler would generate an object file, which by your own admission above, generated more code than could fit in the memory space available. You accepted her argument that the human was required to generate code more efficient than that produced by the microcode compiler. You protest _too loudly_ my friend. William R. Buckley

26 years, 8 months

homemade computer for fun and experience...

by edick＠idcomm.com

DIN41612 connectors are the type used in Multibus-II, VME and SUN, MAC-II's NuBus, etc. They have a matrix of 3 rows of 32 holes in the socket, of which you can buy connectors which only have the outer rows populated. This means that there remain 64 holes, 62 of which would be occupied by a wire-wrap (2-level) ISA-8-bit connector. This would allow placement of the "daughter" board close to the S-100 board's surface and permit fitting it into a single slot of the S-100, provided the end-plate were removed. They can be had in either straight or right-angle versions, though the right-angle normally sits on the circuit card while the straight versions are mounted to the backplane. That's why I suggested that the gender would have to be reversed. Dick -----Original Message----- From: Dave Dameron <ddameron(a)earthlink.net> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 10:13 PM Subject: Re: homemade computer for fun and experience... >Hi all, >At 10:52 PM 4/3/99 -0700, you wrote: >>Well . . . I did think one could get two short cards on one S-100. I did >>have something concrete in mind, too. If one inserts a wire-wrap 62 pin >>(8-bit ISA) connector into a DIN 41612 right-angle socket >>> >What do DIN 41612 connectors look like? >-Dave >

26 years, 8 months

Fwd: older computer stuffs

by bluoval＠mindspring.com

>from a post in alt.forsale: original poster is: c-bristol(a)usa.net (LA., CA) *** OLD COMPUTER EQUIP. NOT IBM STYLE, UNIX PDP-11, VIC20******** DOCUMENTATION: SOFTWARE: UNIX: full sets of docs for v.6, v.7, 4.1BSD, 4.2BSD, 4.3BSD, SUN OS2, SUN OS3, SunView. About 3 big file boxes of UNIX docs. Also have distribution tape of v.7 for PDP-11 licensed to me from SCO (Santa Cruz Operation) and the PDP11 hardware it is licensed for. I paid $1350 to SCO for this licence and tape, forsale now Cheap! Original v6 Lyons course, 1978?. Bell SysV Driver writing course, 1985. DOCUMENTATION: SOFTWARE: DEC OS: Heathkit H-11 paper tape operating system, papertape media and docs, new, as shipped from Heathkit. DOCUMENTATION: SOFTWARE: DEC OSs: Full set, RT-11 v2, v3, v4, partial RSX-11. Also have the software on floppy and RK05, and the PDP-11's that are licensed to run it. Also Heathkit H-11 paper tape operating system, media and docs, new. Also a couple of RSTS/E manuals. Disks also (RX01, RL01,RK05). RT-11 set, XXDP Diagnostics, on 8" RX01 floppies and paper tape.MOSTLY SOLD DOCUMENTATION: SOFTWARE: DEC OSs: Full set, RT-11 v2, v3, v4, partial RSX-11. Also have the software on floppy and RK05, and the PDP-11's that are licensed to run it. Cheap! MOSTLY SOLD DOCUMENTATION: HARDWARE: many DEC PDP-11 docs from 1970-1985 on microfiche. (Have reader too.) MOSTLY SOLD

26 years, 8 months

Is this normal? ODT Question

by cmcmanis＠mcmanis.com

So I've got a Q-bus system with 64KW (128KB) of RAM that is allegedly an 18 bit backplane. When I'm in ODT I can type: @177770/ And enter values for 1777772, 1777774, 1777776, and then it wraps around to 000000. If I start at 200000 it works until 3777777 and then wraps to 2000000. So it seems to not cross a 64KB boundary. Also the boot area is 177300 ? so it is in the upper 4K of the 64KB address space, is it legal to have memory "above" the I/O page? --Chuck

26 years, 8 months

microcode, compilers, and supercomputer architecture

by hhacker＠home.com

>> It is clearly the case that automated mechanisms are >> inferior to a quality human intelligence. For anyone to think otherwise >> is to relegate decisions of life to a computer program. > >We don't need to bring moralizing into the discussion. Most of us already >relegate a lot of life's decisions, including some life-critical ones, to >computers every day. > >Or are you the kind of person that refuses to buy cars with antilock brake >systems? Use of such systems does not imply that I fail to recognise their limitations. William R. Buckley

26 years, 8 months

[Fwd: FREE Computers - Especially for collectors! (AUS)]

by djenner＠halcyon.com

Heads up for you down under. -------- Original Message -------- Subject: FREE Computers - Especially for collectors! (AUS) Date: 5 Apr 99 02:48:51 -0900 From: "Lazy Bone" <zhulien(a)alphalink.com.au> Organization: Badly Configured Clients, Inc. Newsgroups: alphalink.forsale,comp.os.cpm I have the following computers to give away if you collect them ASAP - otherwise I will throw them away: - Panther 128, 2 x 5.25" FDD, 6502 based, 128kb RAM? - TRS80 MC10 (appears complete) - TRS80 COCO - TRS80 COCO2 - CAT - Spectravideo SV318, Keyboard, Manual - Spectravideo SV328, Keyboard, Manual, SV601 Expander, 5.25" FDD (SV902), Cassette (SV903), CP/M 2.2... - SONY Hitbit HB75B MSX - Peach (Hitatchi MB6890) & software - Atari 800XL - Spectrum+ (needs keyboard replacement) & software - Apple 2e, 5.25" FDD, various expansion cards - Apple 2e clone, 5.25" FDD - BBC ModelB, Builtin modem & ROM, Colour Monitor, 2 x 5.25" FDD - Sinclair QL (Telecom ComputerPhone), 2 x microdrives - Microbee model 2, seikosha printer - Microbee model 2 - VZ300 - VZ300 (faulty?) - Sega Master System - Sega Master System 2 - Sega Megadrive 2 - Nintendo NES - Sinclair ZX81 in original box missing cables Since I picked up 40 or so computers from a friend today who is going abroad, I cannot keep the above because of lack of space. If you want to collect anything, please ring me ASAP on 03 98131630. Julian

26 years, 8 months

11/73->RL02 Final

by jpl15＠netcom.com

Well. Over forty messages spawned from this topic. I am very most certainly grateful to each of you who has taken your time and expertise to add knowledge to the subject. I am not going to pursue the 11/73 any longer, because it is hardly a DEC machine, anyway (physically at any rate) and because I think that I would be better served by putting the resources into my 11/44. I have two 11/23s which *are* true-DEC, and perhaps these can be made to hold aloft the LSI banner in my collection. I definately want the 11/73 for the data on it's HD, tho. This leaves the 11/43a system and the uVAX II to be made to speak RL02, and then there's some form of networking between them, and also to a contemplated 486 or 586 platform dedicated to one of the PDP11 emulators. To this machine I can then install my SCSI 9trk drive, and do real handy things like CDROM and Media Conversion. I know the PR1ME 2550 has an ethernet port on it, and a SCSI port, and it has a Kennedy 9100 native to it... Sigh. I have an appointment with a friend of mine who is an electrician, to get an estimate on re-working my pitiful sixties-era house wiring. If I squeeze every drop out of the taxes this year, it might just pay for the sub-panel and the conduit run to the Machines. Yup. I got it *bad*... Thanks again everyone. I am going to take stock of my DEC module situation and then put some things up for trade... I'm angling for an RL02 on the uVAX... hint hint hint. Ah, damn.. forgot about the MINCs.... Cheerz John

26 years, 8 months

homemade computer for fun and experience...

by CLASSICCMP＠trailing-edge.com

> Why restrict yourself to PC-clone keyboards? May as well just put a > serial console port on and ... >Because, as I have traced around countless motherboards of all >kinds and found this is far easier to cobble up one using keyboard, >KB controller stolen from old motherboard, than trying to design >and build a parallel KB or design an i/o and needed codes for >terminal. "Designing an I/O and needed codes for a terminal" is dead simple. Put in a UART, put in TTL to RS232 or 20mA level translators, and you're done. Want to output a letter in the console? OUT 00H. Want to input a character? INP 00H. Come on guys, I'm *not* trying to be difficult. I'm pointing out that a serial console interface is: 1. Universal. No need to find a particular keyboard design or a particular monitor scan rate and/or interface. 2. Easy to build - it's just a UART hooked to an I/O port. 3. Easy to program - heck, with many UART's you get interrupt-driven input and output for free. And no need to write a terminal emulator! 4. Doesn't take up valuable memory space like memory-mapped video. 5. Gives enormous interfacing flexibility. You can hook it to a terminal, you can hook it to a ASR-33, you can hook it to your PC-clone, you can put a modem on it and dial into it. You're in fat city. In brief, it's the option that gives you the most advantages with the least effort. A no-brainer! > I have heard horror stories from some who did the parallel > kbs and they're no longer made. I could be mistaken. And I think folks who build video generators will run across the same problem in the future. The computer will easily outlast several generations of monitors and keyboards, and you want to be able to still use it in 20 years, don't you? I can use my 24-year-old S-100 boxes with serial console interfaces just fine today, just as I can use my 30-year old PDP-8 with anything that has a serial interface, and I expect that I'll be able to use them 30 years from now. Do you think you'll be able to buy new VGA (much less EGA) monitors 20 years from now? Heck, the FCC has an executive order that NTSC television will be gone and replaced by HDTV in less than a decade - better start buying up composite-input monitors now while they're still out there! -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 8 months

Lisp, the machine language. Was Re: Hallelujah!

by hhacker＠home.com

>> computers, the service representative came to the site, opened a panel >> on the operator console, and changed the 5 1/4" floppy disk. By doing > >I think I read somewhere that the 8" floppy was originally designed for >this purpose. This may be. Yet, this was my introduction to the 5 1/4" format. At the time, I worked for Remex, a division of EX-CEL-O corporation, and they made 8" and 5 1/4" inch drives. The year, IIRC, was 1977. William R. Buckley

26 years, 8 months

RLV11/RL02 ->11/73?

by CLASSICCMP＠trailing-edge.com

>>The field guide claims at its top: >> >>*This list may always be found on sunsite.unc.edu, in the following >>*directory: >>*/pub/academic/computer-science/history/pdp-11/hardware/field-guide.txt >But for how long will sunsite.unc.edu resolve to metalab.unc.edu? Probably forever :-). Still, I should fix it up with the new "sanitized" name. It was only a few weeks ago that I thoroughly replaced my "triumf.ca" address on the web pages there... -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 8 months

Hallelujah!

by allisonp＠world.std.com

16megs is the minimum to run W95 in my experience and it runs much better with 32m. It's a pig. <My P200 machine, when with only 32 meg, swapped itself to pieces it seemed <after a few days since a reboot even though I'd shut down all unused apps <to run one. System resources still were not released. After kicking up to <64 meg I now can go for several weeks until needing a restart to recover. It's called memory leaks. Seems some applications do not return resources to the pool as do some win95 drivers. often it can be tracked to one bad driver. And to think my uVAXII is still running with the 9meg that I used to service a half dozen users plus network activity. Allison

26 years, 8 months

homemade computer for fun and experience...

by edick＠idcomm.com

Again, I have to agree about the "waste-of-trees" nature of most "technical" documents these days. Nevertheless, I find it easier to understand the result of a SPICE simulation when displayed graphically, e.g. with PROBE as supplied with PSpice, as opposed to a 2-page long list of raw values. It's true, SOME terminals, more recently than when I last bought one, but nevertheless SOME terminals, were capable of graphic display. They just weren't up to what a PC could do unless you paid more than what a PC would cost. I already stated that the "old" machines did the "old" and in many instances quite persistent tasks well, and still would, given a chance. People have learned, however, that it's not as beneficial to have OLD hardware as to have new, not because of what it will do, but what it won't. I don't mean that it won't break. Any hardware can fail. It's a statistical reality. However, if you try to repair that old, fine, terminal you bought in the '80's you'll find you can't get it fixed for less than the cost of a PC. If, however, you break your PC, there's really nothing you can't repair or replace for much less than the cost of the original. Dick -----Original Message----- From: Tony Duell <ard(a)p850ug1.demon.co.uk> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 6:31 PM Subject: Re: homemade computer for fun and experience... >> What's happened over the years, however, is that people, having seen what a >> computer CAN do as shown in games, etc, have actually found ways to make >> data easier to interpret, and perhaps to add meaning and emphasis to a >> presentation, making it more persuasive, if not more informative, by using >> the graphical capabilities of a computer. > >Odd... I much prefer text to graphics for just about everything. Sure I >like circuit diagrams. And graphs, of course. But I find the typical '4 >colour glossy' that passes for a technical document these days to be a >waste of trees. I'd much rather sit down with an informative piece of text. > >> If you use a terminal, that's what you've got. There were, for a time, >> attempts made at graphic terminals. These failed, however, because there > >AFAIK X-terminals are still in use.... > >> weren't standards on which they could base their usage. Consequently, if >> one didn't have certain hardware, there were limitations on the software he >> could use. Today, that's not the case, as EVERYONE has a PC clone with at >> least 1Kx768 pixels in 256 or more colors. EVERYONE has fairly ample > >Do they? I don't. My PC has Hercules and CGA graphics only. I don't own a >VGA card (I might have an EGA card somewhere, but I don't use it). > >> Today, no one would normally consider a CP/M box for "useful" and essential > >Depends on the 'useful work'. I've done seriously useful work on a Z80 >machine in the last year or so (admittedly running LS-DOS and not CP/M). It >depends on what you class as 'useful work'. My old 8-bitters can still >talk to the special interfaces I've designed to (e.g.) test cabling, dump >ROMs, etc. Sure, I could use a PC. But have you tried getting the same >level of docs for a PC-clone as I have for my TRS-80 Model 4? The latter >is much easier to repair and keep running > >-tony > >

26 years, 8 months

homemade computer for fun and experience...

by CLASSICCMP＠trailing-edge.com

>The goal: 8 bit or 16bit, running from ROM's for software and store >work files on HD, tape or floppy, text based on 6845 IC or similar. >That is beggining, in the end should able to run CPM or something. >I prefer to interface the PC keyboards to it as by make up the >convertor to something that cpu understands by microcontroller or >like. Why restrict yourself to PC-clone keyboards? May as well just put a serial port on it, that way you can use just about any terminal with it and won't restrict yourself to specific hardware. >I have so many TTL's and LSI's and some VLSI's, CPU's of all >kinds (intel, Zilog and others), memories, different crystrals and >oscillators. Should it be single board with everything on it in >stages or do it modular via cards? A CP/M-capable computer doesn't have to be very big at all these days - there are several commercially available designs/kits/boards which are a single PC board with just a couple of chips. The comp.os.cpm FAQ gives links to several of these designs. If I were you, I wouldn't restrict myself to what's in the junk box. Total semiconductor price for a CP/M capable computer can be kept to well under $25 using new parts. If I were doing it, I'd go surface mount, just to see if I could do it in under 2 square inches :-). -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 8 months

homemade computer for fun and experience...

by CLASSICCMP＠trailing-edge.com

>Keep in mind, folks, that some of us remember when there simply weren't >computers which we could use. Back when I was a boy, even the US GOV >couldn't afford a computer capable of what my smallest simplest Windows9x >system is capable. The fact that I don't use it for pure number-crunching >is a recognition that there are other things equally deserving of the >benefits of advancing technology. If a picture is worth a thousand words, >then why type them if it's easier to draw the graphic representation. >Moreover, if you have to read my 1000 words (about a page) and then draw >yourself a graphic representation to understand and digest it anyway, why >not stick to the graphic? A simple graphic can save both ends of a >communication time, effort, and embarassment from when there's a >miscommunication. And a graphic display is a sure way to make certain that a human is necessary at every step of processing, making it difficult to impossible to automate many tasks. You can't search images for the occurence of a particular object. Graphics are the first step to the point-and-drool interface you find on just about every computer these days, where quality of presentation is emphasized over quality of content. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 8 months

Lisp, the machine language. Was Re: Hallelujah!

by hhacker＠home.com

>"Buck Savage" <hhacker(a)home.com> wrote: >> Actually, microcode is not compiled. > >All the microcode I've ever written was compiled. Of course, it was >compiled from special source languages defined for that explicit purpose. >No one with any sense would write a non-trivial amount of microcode any >other way. > >> The i860 is a single chip implementation of the Cray-1, > >No, it isn't. Don't believe all the marketing hype you read; those guys are >paid to lie their asses off. The architecture isn't even *close* to that of >the Cray-1. In particular, the i860 is not a vector processor. It is a >primitive superscalar processor, with a lot of the pipeline exposed to the >programmer. It is tough to write a good compiler for it. > >> and provides just about the same throughput as the Cray-1. > >Almost, for some things. But not for heavily vectorizable problems. For the HP 21MX, microcode looks like assembly language, so any tool used for translation purposes is, by definition, not a compiler. It may be that compilable languages are defined for the purpose of providing for microcode but, that would mean that the sequence of microinstructions is generally not predictable from the source code of the program thus translated. Maximisation of processor throughput, and minimization of microinstruction count, is at least half the purpose of microprogramming. For such optimisation to be effected, on must necessarily write directly in microcode, either bit and byte streams, or coded as in assembly languages. In any case, the use of a language translator always results in a reduction of process throughput. Recall that microcode involves the establishment of timing signals at critical control points within electronic circuits and, the selection of data paths within those circuits. Given this fact, there seems little reason to leave the efficiency of microcode up to the accuracy of a language translator, which we all know to be generally less accurate that the results obtained by a skilled human programmer. I would be grateful to learn from you of the tools you used in the preparation of microcode. All of the work I did was in graduate school in the early 90's, and to date I have not seen a single job made available to a microprogrammer type. I would really love to have an opportunity to perform this kind of work as a job function. As for the i860, sure, it is not actually the equal of a Cray-1 but, the architecture is equal to that of the processor section of the Cray-1. The chief difference in capacity lies in the memory architecture and other support hardware, all of which is external to the processor. The literature with which I am familiar regarding the Cray-1 states that it can perform two multiplies, involving four different operand, at a single machine clock cycle, and this is exactly the capability of the i860. Further, I should like to know in what ways you deem the Cray-1 to differ from the i860, particularly with regard to the processor section. Have you actually used the i860?

26 years, 8 months

Emulating classic terminals

by CLASSICCMP＠trailing-edge.com

> Well, maybe it's donator's remorse, but I gave away my VT100's and 220's a > long time ago. I never had any strong feelings about ANSI terminals, having > lived without them for so long. On the other hand, I've lived with them for decades, and couldn't imagine being without them. They're the bread and butter of being able to interface with a wide variety of software on a wide variety of platforms! >What I would use is one of the simple display terminal routines available in >the public domain. There are plenty of them which emulate ANSI terminals if >that's what's wanted. And 99.9% of them are lousy. (In large part because the current generation of VT100 emulator writers have never even seen a real VT100, much less actually read the VT100 spec.) For a comparison of many products, both commercial and freeware, using an excellent test suite called "vttest", take a look at http://www.columbia.edu/kermit/k95compare.html Another very excellent resource on the subject is at Rick Shuford's web site, http://www.cs.utk.edu/~shuford/terminal/ -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 8 months

homemade computer for fun and experience...

by edick＠idcomm.com

This is a sad but true artifact of the GUI. The best PC/Win95 backup program I have trips all over itself because it wants a human response to a query about whether or not to backup a file created by the backup program. It's not a BIG file, and it doesn't hurt having it there, nor would it hurt if it were left out. The default, however, and you can't get away from that, is to ask. I surely wish that were the only such case. Dick -----Original Message----- From: CLASSICCMP(a)trailing-edge.com <CLASSICCMP(a)trailing-edge.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 5:50 PM Subject: Re: homemade computer for fun and experience... >>Keep in mind, folks, that some of us remember when there simply weren't <snip> >>miscommunication. > >And a graphic display is a sure way to make certain that a human is >necessary at every step of processing, making it difficult to impossible >to automate many tasks. You can't search images for the occurence >of a particular object. Graphics are the first step to the point-and-drool >interface you find on just about every computer these days, where quality of >presentation is emphasized over quality of content. > >-- > Tim Shoppa Email: shoppa(a)trailing-edge.com > Trailing Edge Technology WWW: http://www.trailing-edge.com/ > 7328 Bradley Blvd Voice: 301-767-5917 > Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 8 months

bringing up an 8f...

by allisonp＠world.std.com

<I've got the 8/e frontpanel prints here. From what I remember the 8/f is <a little different. The displays are leds (minor change around that part), otherwise it's identical to the 8e. <THe frontpanel display logic is mostly built from diode transmission <gates - this circuit < <In---->|-----+-----|<------+--- Lamp driver < | | <Sel-\/\/-----+ | < | <>From other gates-----------+ <for that lamp Does not compute based on the chip part numbers. <The MD inputs have their own set of gates. I'd start by tracing from MD1 <(pin AL1) through the diodes to the appropriate 380 lamp driver <(E26/6,7,2 on the 8/e). My guess is an open-circuit diode... Ther are very few diodes and the drivers appear to be 7404s with 74l54s used as selectors. Restate the problem... The display is the variable 12bit on off the rotary switch and only occures when MD is selected. This suggests the data selector logic or it's particular source on the board as MD on the bus has the correct data. <Oh, these old machines are quite easy to work on (famous last words...) Generally the PDP-8 series is fairly straightforward. Allison

26 years, 8 months

homemade computer for fun and experience...

by edick＠idcomm.com

Well, maybe it's donator's remorse, but I gave away my VT100's and 220's a long time ago. I never had any strong feelings about ANSI terminals, having lived without them for so long. What I would use is one of the simple display terminal routines available in the public domain. There are plenty of them which emulate ANSI terminals if that's what's wanted. Just an ADM-3A or HAZELTINE-1500-equivalent function set would be adequate. Building in enhancements over what was done back when the computer was new would not be my goal. I'm always into exploiting the fact that these machines were once, and, hence, can still be, useful. I'd emphasize that the computers we use today, fast and fancy though they may be, don't really process text in a word processing vein much better than they could 20 years ago. Likewise, if it rolled out the payroll in accordance with both laws and schedules, it would probably still do that today. Dick -----Original Message----- From: Allison J Parent <allisonp(a)world.std.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 5:27 PM Subject: Re: homemade computer for fun and experience... ><Admittedly, many folks seem to believe that a computer must have ><a video generator to be a "computer". > >Retrorevisionist PCism. Though a VC8E is a definate computer thing. > >< My CP/M experience started with ><Model 33 Teletypes and blinkenlights front panels, so perhaps I'm the odd m ><out here. > >Same here. It's seems silly for me to recreate the logic and programming >of my vt100 when I have a vt100 that works better than any I could put >together. There is advantages to useing a PC keyboard and monitor as they >already take space on my desk but then again I can provide a serial port >and use the PC for a terminal. > >Allison >

26 years, 8 months

homemade computer for fun and experience...

by edick＠idcomm.com

I have some reservations about your opeing assertion. I'd modify it to say that articles are sometimes descriptions of circuits that work, sometimes. I know people who build a circuit and try it once. If it works they say they have the circuit working, and if it doesn't, they only say they have it built. There are fellows I know who seem to be quite competent at building circuits, yet I see their stuff working and I see it malfunctioning, both. Sometimes I believe their circuits/assembly techniues to be solid, sometimes not. If I'm interested in applying a technology demonstrated in this manner, I often try it myself, sometimes simulating it first, if I have doubts about the validity of the underlying theory. The fact that a circuit LOOKS good doesn't excuse you from performing the requisite analysis. I've seen more error committed on the basis of inadequate analysis than probably any other reason. I seriously doubt, however, that anyone has written an article about mounting two ISA cards on an S-100 board which occupies only a single card slot when finished. That's what I was describing. I believe that's what is needed, as opposed, say, to a multi-board interface, occupying, say, the last position in a cardcage, thereby allowing cards to protrude somewhat beyond the end of the cardcage. I'd consider that a believable approach. The reason I say this is that the only way one gets to the notion I described is by ordering the DIN 41612 connectors with their genders reversed. Only a true dummy (referring to ME, of course) would do such a silly thing. I've got a basement full of circuits which didn't work though they were copied from the application note. There are also a number which do work, but I mostly delivered the working ones to someone who paid for them. Dick -----Original Message----- From: Allison J Parent <allisonp(a)world.std.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 5:27 PM Subject: Re: homemade computer for fun and experience... ><>Been there and done that. ><>Also, there are no less than two articles on how to go from s100 to ISA. ><> ><There's a substantial reach from an article to a solid and working circuit ><on a board capable of actually supporting the functions. This is > >The articles actually are descriptions of circuits that do work. > ><particularly true since, now, the user is required to understand the inner ><workings of his own machine as well as those of the card he wishes to use. ><Having the usual inkling about ISA is not always sufficient. > >That was true then. Unlike PCs with plug and pray configuring a s100 >system meant you generally had knowledge and documentation or were plain >crazy. > ><><ISA cards on a single s-100 board. This would certainly be cheap enough ><><most cases, to warrant such an effort. The software might get to be a ><><problem, though. >< ><Yes, and therein lies the "problem" for the average user. > >define average user... today that's mom and pop that buy a PC and plug >it in. Definatly not the case in 1980. The reality of older computers >like the S100, SS50, Multibus types were you had to be a knowledgeable >user. Or if that was a problem you went to Apple or TRS80 styled machine >where the hardware was generally a fixed and software was the experimental >arena. > >Allison >

26 years, 8 months

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