test-drb May 2010

test-drb@ccmp.vtda.org

189 participants
248 discussions

by lynchaj＠yahoo.com

Hi! It pains me to ask this, what vendors are hobbyists using for low cost, low quantity prototype PCBs? I've used Advanced Circuits and they've been pretty good. I would love to stick with them as their barebonesPCB is a deal. 33each looks interesting too. However, I am starting to have problems with them unrelated to the PCBs and am investigating what other sources are available. I am trying to get some prototype PCBs to evaluate some S-100 boards in development (S-100 System Monitor Board, S-100 Bus Extender, S-100 Z80 CPU, etc) Any ideas? Constructive suggestions appreciated. Thanks in advance. Have a nice day! Andrew Lynch

14 years, 5 months

Lisa C and Lisa FORTRAN

by jonas＠otter.se

Obviously this Dan fellow is a troll and you have all taken the bait... >From: Dan Gahlinger <dgahling at hotmail.com> >Subject: RE: Lisa C and Lisa FORTRAN >To: <cctalk at classiccmp.org> >Message-ID: <BLU139-W31C114B43954AB9926E817C9F70 at phx.gbl> >Content-Type: text/plain; charset="iso-8859-1" > > >In this case, Fred's just, ok, can't say anything nice, don't say anything, >he's gone to my ignore list, it's better this way... > >as for Valtrep, a lot just personal experience, remember I worked on it, in the 80s and before in the 70s. > >it's interesting even info on the old "Sentry-70" computer system can't be found online, at least, I can't find any. >The Sentry-70 is as it suggests, the last model, and numbered by year. that would be 1970. >It predates the Cyber/Prime system, as much as memory recalls anyhow. > >They had the Sentry-70 at the university I happened to be at, at the time. >I started there in 1976, yeah I know, it's still late for the time periods we're talking about. >However, the systems and languages had been there for a long time before I started. > >There are a few things that lend evidence to these statements, none of which are likely verifiable... > >1. that is how Valtrep was introduced to me (ok, so it's hearsay) >2. more importantly - the structure of the language - and this is more telling. > >It's quite easy to identify a more primitive version of a language when compared to a more modern one. >Syntax, functions, scope, definitions, everything about it. > >Do I have any sample code of Valtrep still around? That's a tough question. >I'm going to guess "NO", however, it is certainly possible. I will definitely look. > >There are a few people who were at the same university with me at the same time, >I can also consult with them and perhaps get some of their memories, >one of them may even have sample code, if only on punch-card or whatever. > >It might be easier [sic] to find info on the computer "Sentry-70", but all my searches thus far have come up blank >on any useful information anyhow. > >I'm willing to cede the argument that Valtrep was the predecessor to Fortran if anyone can offer any evidence to support that. >Perhaps it's an odd claim to make without any backup, but then, I was there, so.... > >Valtrep was very "Fortran-ish" however it didn't have all the functions or capabilities, it was more rudimentary. > >Dan. >

14 years, 5 months

Radio Shack Science Fair manuals

by kgriff156＠comcast.net

I am inquiring to see if you might help me to acquire a 28-249 manual for a 200 in 1 kit I am helping my grandson learn with. The 150 in 1 manual that we have does not match the set up or numbering of components for him to follow. I await your response and thank you for your assistance. Kevin

14 years, 5 months

Unsticking an RD53

by steve＠cosam.org

Rob Jarratt wrote: > A while ago I posted about an RD53 I have which had the problem with the > sticking heads. I have now got to the point where the heads no longer stick > on the bumper, but the disk still does not work correctly. I opened it up > and watched what it did with the cover off. Once it gains speed it moves the > heads out all the way and then they just stay there with the disk spinning. FWIW, I have one that does exactly the same. It is however also a non-runner, so I can't tell you whether that's correct behaviour or not. It certainly /sounds/ the same as my other, working example. > There is a whine coming from the drive, not sure of the source of this > though. Mine had that too. Not sure where it came from, but it stopped when I retightened one of the corner HDA mountings (the ones with the rubber bushes underneath). Cheers, -- Steve Maddison http://www.cosam.org/

14 years, 5 months

Procom CD Tower - drivers?

by silent700＠gmail.com

I've dug out of my garage a Procom CDT-7-4X-ET cdrom tower. It's got seven Plextor 4x SCSI drives and It appears to be networkable. Anyone have any idea how to access it over the network? Maybe reset the ethernet module to a known IP? I can't even find a MAC address on the case anywhere. Granted, it's not much as use now as in the days when having 7x640mb online and not having to put it on disc was a big deal, but like all the old junk lying around here, I'd like to see it working once. And I'm thinking the CDROMs could possibly be replaced with hard drives (if supported by the firmware in the tower.) TIA -- jht

14 years, 5 months

Looking for a vintage computer for film in Oz...

by cclist＠sydex.com

(Cross-posted from Erik's VC Forum) http://www.vintage-computer.com/vcforum/showthread.php?20406-Wanted- mid-70-s-computer-to-appear-in-film-Bank-scene Cheers, Chuck

14 years, 5 months

Processor sizes (was Greatest videogame device)

by roger.holmes＠microspot.co.uk

On 9 May 2010, at 00:02, cctalk-request at classiccmp.org wrote: > Message: 24 > Date: Sat, 8 May 2010 13:37:11 -0700 (PDT) > From: Fred Cisin <cisin at xenosoft.com> > Subject: Re: Greatest videogame device (was Re: An option - Re: > thebeginningof > To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> > Message-ID: <20100508132544.P80526 at shell.lmi.net> > Content-Type: TEXT/PLAIN; charset=US-ASCII > > On Sat, 8 May 2010, Tony Duell wrote: >>>> Is the size of the data bus irrelevant? >>>> (There have been people who maintain that THAT is the measure of the >>>> processor!) >>> >>> They're wrong :-). The "size" of the CPU is defined by the size of the >>> internal registers. I am astonished there is actual discussion debating >>> this. >> >> Ah, so a Z80 is a 16 bit processor (IX, IY, SP and PC are all 16 bits, >> and there is no documented way to use half of them (Yes I do know about >> some of the undocumented ways)). >> >>> >>> I think people who maintain the size of the data bus as being the >>> measure of a CPU are hardware people who have never optimized an inner >>> loop in machine code. No I am first and foremost a programmer who has picked up hardware by buying an old mainframe (before home computers existed) and maintaining it. The 'largest addressable unit of storage' I was taught in my computer science degree is now outdated. I have read many specifications issued by microprocessor manufacturers (who should know what they are talking about surely) who define their computers by their data bus width, for instance Intel define the 8088 as an 8 bit computers system. It the chip maker says their chip is an 8 bit processor why should it become a 16 bit computer when you merely plug that chip into a motherboard and the marketing people call it 16 bit. >> >> Conversely I could claim that those who calim the 8088 is a 16 bit >> processor have never wire-wrapped the data bus connections to one, and >> found there are only 8 to wire up. > > The problem remains that we are trying to come up with a single > quantification for measuring something with multiple variable > characteristics. Yes, and there are other aspects to be considered too. Whilst I have always thought of my ICT1301 as a 48 bit computer because it has a 48 (+ 2 parity) bit data bus but the engineers of the day called it a 4/12 system meaning 4 bits parallel x 12 digits serial. The mill (ALU) is only 4 bits wide but the three arithmetic registers are 48 bits and it had three 24 bit 'control' registers which hold instructions and it has no program counter register at all. > If we were to grossly oversimplify, > and use the most "popular" quantifiers, > we would still have two characteristics to measure. > the 8080 is 8 bit software, 8 bit hardware > the 8088 is 16 bit software, 8 bit hardware. > the 8086 is 16 bit software, 16 bit hardware. > the 80286 is 16 bit software, 16 bit hardware. > the 80386SX is 32 bit software, 16 bit hardware. > the 80386DX is 32 bit software, 32 bit hardware. > the Sentry-70 is unknown. > > But this does not invalidate the measuring systems used for different > types, and it is still trivially easy to come up with defensible ways to > measure with different end results. We should consider what the bit size is used for. To users they expect speed to increase with size. An 8088 and an 8086 or a 68008, 68000 and 68020/30/40 have the same internal architecture but the speed of operation is not the same, the cpu has to go to make more memory accesses with a narrower data bus. This does affect speed and to the poster who referred to "hardware people who have never optimized an inner loop in machine code" I should point out that if he optimised his loop on a machine with an 8 bit data bus and expects that the loop will still be optimal on a 16, 32 or 64 bit data bus processor then he is almost certainly wrong. It won't be far off, and MIGHT be optimal but until you do that again (As I have done MANY times) you cannot be sure it could not be tweaked to give a more optimal loop on a wider data bus width. Even turning off the cache memory can make a bit difference, and on one memory occasion I found that emulated 68k assembler running on a PowerPC ran quicker than the same code re-written in native C on the same PowerPC processor. The code was simply for rotating a one bit deep bit map 90 degrees and after looking in great detail at the generated PPC code the only explanation I could come up with was that the possibility that the 68k emulator turned off the RAM cache which meant that when my code wanted to read a word the PPC was doing four memory accesses to load up the entire cache line, three of which were pointless because for a large bitmap they would be purged before the other three were used, whereas the 68k emulator just did one memory access. I imaging the emulator locked the cache so its own code would not be purged. Roger Holmes. > > > Now, what are the definitions of "microcomputer", "minicomputer", > "mainframe"?

14 years, 5 months

Lisa C and Lisa FORTRAN

by roger.holmes＠microspot.co.uk

On 9 May 2010, at 00:02, cctalk-request at classiccmp.org wrote: > > Message: 8 > Date: Sat, 8 May 2010 13:26:17 -0400 > From: Dan Gahlinger <dgahling at hotmail.com> > Subject: RE: Lisa C and Lisa FORTRAN > To: <cctalk at classiccmp.org> > Message-ID: <BLU139-W2772A8B808F739798BAD2C9F70 at phx.gbl> > Content-Type: text/plain; charset="iso-8859-1" > > > technically, looms count, they have to, to know how many times to do a particular pattern. > that would make such programming language back into the 17th century at least ;) I think you have missed the point that this is a discussion of high level languages. I have not heard that any 17th century loom had a high level language. > >> Date: Sat, 8 May 2010 01:00:14 -0600 >> From: bfranchuk at jetnet.ab.ca >> To: >> Subject: Re: Lisa C and Lisa FORTRAN >> >> Dan Gahlinger wrote: >> >>> Fortran the first high-level language, I think that would be open to >>> debate. Indeed, wikipedia says otherwise... and I quote: >>> >>> The first high-level programming language to be designed for a >>> computer was Plankalk?l, developed for the German Z3 by Konrad Zuse >>> between 1943 and 1945. >>> >>> LISP, COBOL and Algol are also mentioned during the 1950s, so "first" >>> is perhaps debateable. Do we count the programmable "Looms" ? >> >> Only if they can count. :) >> >>> There are questions I can't answer at this time. I can just say, from >>> memory, Valtrep was more "primitive" than Fortran, and yet, very >>> "fortran-like", as I said, if you could program Fortran, Valtrep >>> would be easy to pick up. >> It seems to me unlikely, that you would have any other high level >> programs other than a possible assembler and link loader with a few >> odd utility closed subroutines. >> >>> I can't find any information on it, nor can I find any information on >>> the computer system it ran on (that's bad). >>> >>> so to be fair, I'll mark this and file it as "questionable"/"suspect" >>> until some evidence can be shown either way. >> >>> Dan. >>> _________________________________________________________________ Win >>> a $10,000 shopping spree from Hotmail! Enter now. >>> http://go.microsoft.com/?linkid=9729711 >> >

14 years, 5 months

Valtrep is the PREDECESSOR to Fortran (was Lisa C and Lisa FORTRAN)

by shoppa＠trailing-edge.com

Fred writes: > On Fri, 7 May 2010, Randy Dawson wrote: >> put valtrep in quotes on your google search. This cuts back on the >> offending valtrex hits. >> Its there, but in recent history, nowhere near the genesis of FORTRAN. > When I did, I got 28 hits. Other than "Valtrep Optical Scanning > Software", the only computer related ones were message posts by somebody > with a username of "transnet", who "used a Sentry-70 with Valtrep in > 1986", and signed some of his posts with "Dan." > (complete with the period, similar to our "Dan.") > Did you get some hits that I didn't? I think the "is transnet really Dan Gallingher" question is exactly like the "is Tony Clifton really Andy Kaufman" question. Tim.

14 years, 5 months

Lisa C and Lisa FORTRAN

by shoppa＠trailing-edge.com

Fred writes: > In terms of being noticably more primitive, let me offer a hypothesis of > an honest way that Dan could be mistaken: It is not at all uncommon for > universities to proudly use software, including compilers, that were > written by students there. Such student written materials may be quite a > bit cruder, and lacking many refinements. Did your first attempt at > writing a C compiler include floating point? It may not always be > feasable to differentiate between earlier software V modern early efforts > by talented programming students. After all, that seems to be how we > ended up with the UCSD Pascal and P-System, in which certain > characteristics are noticably more primitive than much of the commercial > software of the time, while certain other characteristics may be novel and > innovative. Many languages of the 60's and 70's were horribly over-specified and the "full language" in fact had a lot of features that were not desirable. Some of these were developed at schools as local products that were never released, and others did become products with a life outside the school. Others were developed by minicomputer companies because the "full mainframe language" was not practicable on the mini. e.g. WATFIV was like FORTRAN but eliminated the separate complie/link/execute phases and could collapse them. It extended the language in some directions while collapsing it in others. Later on came RATFOR which went in a different direction, adding structured elements onto FORTRAN. e.g. BASIC was supposed to be a simplified version of FORTRAN or ALGOL, but in fact it was simplified even further into things like PILOT. e.g. COBOL is, even today, cantankerous but some concepts from it went into the much streamlined DIBOL. (I hava a sweet spot for DIBOL.) I think a very important concept, is that having more features in a language, especially when those features were specified by a committee, results in an overly complicated overly large cantankerous language. Too bad most people still get sold on features :-(. It's like the DVD players with 141 buttons on the remote - people buy it because it has more buttons or functions, to the point where putting more buttons on becomes a marketing function, not a usability function. Tim.

14 years, 5 months

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test-drb May 2010