test-drb May 2005

test-drb@ccmp.vtda.org

248 participants
723 discussions

by aek＠bitsavers.org

> Since I don't beleive in using > old systems for the recovery of old data, Why? (I feel the opposite, as what better system to get the data than the system it was designed for? I'd like to hear your opinion.) -- Almost all of the data that I recover is done at the physical media level. This is done either with analog to digital converters or modern digital data separators which have better recovery characteristics than the originals. The main reason for wanting to do this is to preserve all of the original bit streams and error checking information. In the case of magentic tape, it is possible to recover data from very old tapes using modern magnetorestrictive head technology that would be impossible to recover using the original heads, since MR heads require MUCH less contact pressure and are much more sensitive than the originals. While it may be practical to maintain microcomputers for this purpose for newer media, the types of data I have been trying to recover (mainframes and older minis) is impractical, either because the machines no longer exist, cannot be kept running given the tradeoff of machine ontime vs the time needed to keep it running, or that the reliablity of the data from older controllers is worse than can be obtained from direct low-level data aquisition. There is also the problem of file transation and transfer even if you can get the bits read on the original system. The problem with using these techniques is it requires detailed knowledge of how the data was written and information on things like file formats. This is why there is a strong bias towards this sort of information on bitsavers (in addition to the fact that I've discovered this information is REALLY hard to find for pre-minicomputer systems). This is also information that is VERY useful to people trying to write simulators.

19 years, 2 months

'goto' - the debate between 'human' vs 'machine' programming

by cmurray＠eagle.ca

Scott wrote in response to: "I absolutely concur with John's conclusion: Academia, the elites or otherwise, saw the 'horrors' of goto and declared it an evil that was to be expunged from any language. The toolbox was diminished by this action in my humble opinion. Yet for us QBasic guys we still employ it. Boy does it get one out of a jam. Mimics real life doesn't it?" "I regard 'goto as the programming equivalent of the adjustable spanner. There are often better tools to use, using it wrongly can get you into real trouble, but it's rare to find a hacker who's not used it (just as mo hardware guy will use an adjustable spanner when there are better tools available, but I don't know of a serious hardware hacker who doesn't have one in the toolbox...) -tony " Heck, I even have an adjustable box-end wrench. *ducks* The folks who deplore GOTO are the 'Structured Programming' folks. Who have a lot of flavors and attempts at 'structured programming' behind them now, and keep chugging along. It's about sociable coding, as opposed to asocial 'solitary' coding. Which is important. But as an over-experienced Assembly Language programmer, I got into trouble in my 'Intro to C' course because I was in the habit of writing my own functions instead of using The Standard Library. -scott I'm not sure whether programming is done to benefit people or to make machines work better. Since computers are seldom user-friendly, they were'nt but now are easier to use thanks to GUIs, we have to ask then was is programming for? I remember programming in a few-line BASICs, well even further back - soldering a kit and program in strict machine-coding - and I wanted the computer to do certain tasks. I'm not sure these tasks were of any particular benefit done on an expensive early computer and they were that! I could do the same thing with pen & paper or a calculator, not spend time writing a few lines of code and hope I didn't make a mistake!!! The calculator was programmed to work efficiently and little or no programming was needed by me to make it work. Social coding here is effective in the sense it solves a problem for me. The machine works in an excellent fashion as a solitary instrument. In this case it benefits me. Is this the true value of programming and using a 'goto' to get out of a jam so to speak can be very effective. Works in real life, particularly useful around Belgian horses. Can this be wrong? Computing forever! Murray

19 years, 2 months

The Don Maslin Software Archive

by aek＠bitsavers.org

> Ok Al, about where do you rate yourself. Tough question.. I have WAAAAAY too much stuff right now. I made the decision about five years ago to get rid of all of my paper by scanning it and donating it to the CHM. The first part mostly happened, but getting rid of the paper didn't and now I have 10x the paper that I did five years ago. I have decided to dispose of a LOT of what I currently have. There is one meta project, the preservation of documentation and software that has to guide what I keep and what I get rid of. Since I don't beleive in using old systems for the recovery of old data, many of the machines I have could go. The physical mechanisms that are necessary (like disc and tape drives) will stay, interfaced to more modern harware.

19 years, 2 months

Tandy T100 info

by ajp166＠bellatlantic.net

> >Subject: Re: Tandy T100 info > From: John Hogerhuis <jhoger at gmail.com> > Date: Mon, 16 May 2005 13:59:50 -0700 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >The basic idea is that Remem implements in CPLD a memory management >unit dividing the 64K address space into 64 1K blocks (actually more >than that since the option ROM is emulated). So you can map any 1K >block from anywhere in RAM or flash into the 64K address space any way >you like. Ok, the usual MMU only fairly fine grained. Does any apps make use of that kind of MMU and space? >For compatibility it also emulates a 256K "Rampac" which is a vintage >external device that hooks to the I/O bus port on a T102. unfamiliar. >There are multiple MMU maps selectable via an I/O instruction for >fast-switching of virtual Model 100 environments. So for example you >can have one map with a native Forth-in-ROM, and a couple of maps with >the standard ROM but distinct RAM portions (the latter much like the >"banks" in a T200 or NEC 8300 laptop) Ok, I've done this on other systems and S100. >Each block in the map can be marked read-only so that if you are >emulating ROM with RAM or flash you get a perfect emulation, i.e. any >writes against ROM don't get applied. Handy! Now I understand what it is and the basic logic inside. Like many MMU based 8bitters the addition of large ram is usually to emulate disk. I'm curious to see if any actually do swaping or overlay so the app can access a larger space or larger data. The reason for that is most cases that is rare or not even done. Allison

19 years, 2 months

Tandy T100 info

by ajp166＠bellatlantic.net

> >Subject: Re: Tandy T100 info > From: John Hogerhuis <jhoger at gmail.com> > Date: Mon, 16 May 2005 12:54:39 -0700 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On 5/16/05, Allison <ajp166 at bellatlantic.net> wrote: > >> >To see "the next level" of Model 100 mod, check this out: >> > >> >http://bitchin100.com/remem_project.htm >> > >> >2 Meg RAM and 4 Megs Flash ROM.... >> > >> >> That is a pretty site, shame behind all the pretty pictures it's a >> grand set of 404s. None of the tech docs are there. >> > >I run Bitchin100.com. I've been pushing Steve to get me a new set of >documents, he moved everything around on his site that I had linked >to. thats understandable, just make the links "under construction" then as we then know something is happening rather than the site appearing abandoned. >Right now he's deep into testing the board, so the stale data sheet >links are indicative of nothing more than priority on getting working >prototypes to the software developers (including me). > >Maybe tonight I'll get rid of the dead links. thanks. >In any event the important specs are summarized there on the left hand column. I read them bit there are some ???? as to how it integrates and is applied. Allison

19 years, 2 months

Making Frontpanel Labels

by gkicomputers＠yahoo.com

I think the places that make custom die cut decals http://www.decaljunky.com/ may also be a good place to make frontpanel labels, they peel off with no background (looks like they were painted on). __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

19 years, 2 months

Tandy T100 info

by ajp166＠bellatlantic.net

> >Subject: Re: Tandy T100 info > From: Roger Merchberger <zmerch at 30below.com> > Date: Mon, 16 May 2005 13:45:31 -0400 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >Rumor has it that Allison may have mentioned these words: > >>I just aquired a Tandy T100, really fun little machine. >>one of the first steps is to exten the ram (24k more is possible) > >Zip on over to my Model 100 listserve - you don't have to be subbed to post >(but please note in your post if you're not subbed, so folks know to cc: >you privately) - there's almost 200 subscribers there... ;-) That may be handy. >To see "the next level" of Model 100 mod, check this out: > >http://bitchin100.com/remem_project.htm > >2 Meg RAM and 4 Megs Flash ROM.... > That is a pretty site, shame behind all the pretty pictures it's a grand set of 404s. None of the tech docs are there. >I only have the schematic for the 200 in paper form, and it's "buried" yet >-- but the manuals are available in PDF form here: > >http://www.club100.org/library/libdoc.html This location I'd not looked at yet. The manual from there is readable and printable (and HUGE!). >If you need parts, I or someone else on the list can get you parts... >;-) I have plenty of 8kx8 and 256kx8s, nice fast CMOS from old 386 and 486 cache memories. those will be the base of the first upgrade (24k more ram for full 32k). The second will be a overlay ram for the lower 32k (for those times when I want a full ram system). Thanks! Allison

19 years, 2 months

wanted: VAXstation 4000/60 16MB memory modules - MS44-CA / MS44-DA

by tgarcia＠hivemind.org

Hello, This is my first post on the list -- greetings! I have filled a VAXstation 4000/60 with four megabyte simms, that I am running vms on as a hobbyist home server... unfortunately this limits me to 32 meg, and about to add Pathworks will certainly tip her over the edge. I was wondering if anyone had any of the 16 megabyte sticks lying around-- part number printed on the board I think is 54-19103-CA , sold in packs of one or two as MS44-CA / MS44-DA respectively. Various other models of the series I believe use them, though not the /96. I would be happy to pay for shipping from anywhere; I am in (old) England. Swap for some four megabyte modules is also possible, if someone needs them instead! Alternatively, any pointers as to where would be good to look would be gratefully received. Cheers, -- Tom Garcia | tgarcia at hivemind.org

19 years, 2 months

Making Frontpanel Labels

by bpettit＠ix.netcom.com

> From: Ethan Dicks <ethan.dicks at gmail.com> > Subject: Today's garage sale findings > To: "General Discussion: On-Topic and Off-Topic Posts" > Speaking of > which, does anyone know if they manufacture an adhesive-backed > _plastic_ sheet that's meant to go through printers? I know I can > pick up an 8.5"x11" paper label from any office supply place. I am > 3M used to make a product that was a thin alunimum with a photo emulsion on it. It worked like a blue print. Make your master on vellim, print it using a blue print machine and develop it with ammonia. I made many very professional looking front panels with this technique. The 3M salesman would sell it by the sheet fairly cheap ( about $1/square foot). It was mounted by peeling off the back to reveal a contact glue. You never got it off again once it was stuck on metal. What I liked about this method was that you could cover up misdrilled holes. The alunimum was think enough that it could cover up unused holes with no denting. Great for covering up sloppy work. Billy

19 years, 2 months

Anybody know what's happened to Jim Kearney?

by rigdonj＠cfl.rr.com

I've been e-mailing Jim for a couple of months and haven't gotten a reply. I found a phone number for him and tried it and found that now it belongs to someone else. The last message that I could find from him was in May 2003. Anybody know what's happened to him? Joe

19 years, 2 months

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test-drb May 2005