May 2024 - cctalk - classiccmp.org

imd2raw.c correction - linearizing ImageDisk images

by David Schmidt

There have been a few versions of the utility imd2raw.c floating around that will take Dave Dunfield's ImageDisk-created images (i.e. an .IMD file) and make a linear binary image devoid of any metadata. This is similar to the function of Dave's IMDU.COM program's /b switch. I've corrected a problem with the assumption that all imd2raw.c descendants to date have made: sectors that have a skew (i.e. not 1-1 interleaved) weren't linearized correctly. The skewed sectors need to be written out in "sorted" order, which is not necessarily captured/physical order. This is easily verified by comparing output from "IMDU /b" to earlier imd2raw outputs on any .IMD that has a sector skew that isn't 1, 2, 3 [...]. It's up on github here: https://github.com/RetroFloppy/imd2raw

1 week, 3 days

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NRAO Data tapes

by Dani Werts

Hello, I'm an employee with the National radio astronomy observatory here in Socorro New Mexico. As part of our NGVLA upgrades, we are seeking to get rid of old data tapes from the tape reel days of Computing. These contain things such as the boot loaders, OS, specific collection programs and antenna movement programs. I personally would hate to see these just wind up in the literal dumpster and would like to see them sent out to a museum or an archiving body that can preserve them and keep them safe as a dynamic part of history. If anyone is interested or knows someone who would be interested in the VLAs data tape library please let me know. V/R Danielle Werts Front end engineer VLA Socorro New Mexico

5 months, 1 week

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Experience using an Altair 8800 ("Personal computer" from 70s)

by Dave Dunfield

I case anyone is interested... I've just passed on my "Mits Altair 8800" - this is a very historic system from the 70s - it is: First Personal Computer (long before IBM PC) First S100 buss system First system Bill Gates wrote code for (long before Microsoft) I did write a pretty decent emulator for my exact Altair system some years ago... And with recent interest in the system, I've just updated it with a few minor improvements and a "cleaned up" edition of the software I created to bootstrap a hardware front-panel based system (no on-board ROM) via a serial port card - requiring you to enter only 18 bytes through the front panel So .. if you'd like to experience what it was like to use a system from the 70s - here's some of the things you can do: Bootstrap it cold Run NorthStar DOS (one of the first commercial DOSes) Run DMF (Device Management Facility) - a DOS I created for it - can you tell that at the time I was working on an IBM mainframe ... my - OS name sounds a lot like various IBM mainframe packages at the time. A few other software setups (for example there's a stand-alone bootable FORTH) Has Editors, Assemblers, BASIC and other tools from the era. and a few games - some written by yours truly - some very early commercial offerings (like "Cranston Manor Adventure", or "Valdez") Note1: My Altair emulator was created under DOS and is a 16 bit program! It does work very well with DosBox (I recommend the one on my site) Note2: I've not updated the ALTAIR.ZIP on "Daves Old Computers" yet - you can get the updated one from: "Daves Old Computers" -> Personal -> Downloads -> OlderDownloadsFromPrevious - look for "ALTAIR" under: Simulators and Emulators *** I don't follow this list nearly as much these days - if you want to reach me, use the contact link on my site! -- ---------------------------------------------------------------------------------- Search "Dave's Old Computers" see "my personal" at bottom!

2 years, 1 month

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Re: C. Gordon Bell, Creator of a Personal Computer Prototype, Dies at 89

by Mark Matlock

In addition to the Goodyear STARAN computer, another tire company Firestone did built some interesting one off systems of unusual design. My first job out of college was with Firestone Central Research. While there, I became friends with William Clayton who was one of three of their research fellows. He was a big proponent of APL and there I was exposed to the MCM/700 (see https://www.softwarepreservation.org/projects/apl/Brochures/MCM700Brochure ) and the IBM 5100 desktop APL computer as well as APL via IBM 360 timeshare. We used APL to simulate the heat flow and rubber curing in very large earth mover tires with finite-element techniques coupled with chemical kinetics. However, Bill Clayton most interesting work was around optimizing formulations from designed experiment data. He built an analog computer that used static card readers that provided contacts to feedback resistors to simultaneous compute the output of 16 second order polynomial equations with cross terms for 8 independent variables. Each of these 16 polynomials had 54 static coefficients that were determined from second order statistical regressions of data from designed experiments. One equation for example might be tensile strength of a rubber compounded with various amounts of sulfur, carbon black, oil, accelerators, etc. Then another equation might represent wear resistance measured from the same combination of compounding ingredients. The 16 equations had upper and lower limits of acceptable values for tensile strength, wear, etc. The analog computer would then begin an exhaustive grid search of the 8 independent variables to find a combination of the 8 ingredients that met all 16 of the desired output traits. When a solution was found the independent variable value voltages were read by an A/D controlled by a PDP-8 and then printed on a console. Thus the system was actually a hybrid computer part analog and part digital. I was told that doing the 8 factor grid search in Fortran on an IBM 360/168 would have taken 1300 hours but this hybrid system did it in 5 minutes, Only three of these systems were ever built, two of which were used outside of Firestone (one by the Air Force). U.S. Patent 3,560,725 from 1968 provides some background as it covered an early version of the later more highly developed system. Mark > From: Paul Koning <paulkoning(a)comcast.net> > Subject: [cctalk] Re: C. Gordon Bell, Creator of a Personal Computer Prototype, Dies at 89 > Date: May 23, 2024 at 6:58:06 PM CDT > To: "cctalk(a)classiccmp.org" <cctalk(a)classiccmp.org> > Cc: Kevin Anderson <kevin_anderson_dbq(a)yahoo.com> > Reply-To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk(a)classiccmp.org> > > > I have a vague memory of visiting the Computer Museum when it was still at DEC, in the Marlboro building (MRO-n). About the only item I recall is a Goodyear STARAN computer (or piece of one). I found it rather surprising to have see a computer made by a tire company. I learned years later that the STARAN is a very unusual architecture, sometimes called a one-bit machine. More precisely, I think it's a derivative of William Shooman's "Orthogonal Computer" vector computer architecture, which was for a while sold by Sanders Associates where he worked. > > paul

2 years, 2 months

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Re: interlace [was: NTSC TV demodulator ]

by CAREY SCHUG

This may have been covered before, VERY early in this tread. I think I tried a game on a flatscreen, and had issues. I don't know if it applies to the radio shack Color Computer, the interest of the original poster. many games and entry pcs with old style tv analog format, don't interlace, and tube TVs nearly all (except maybe a few late model high end ones?) are fine with that, but I seem to recall that most or all digital/flat screen can't deal with non-interlace. <pre>--Carey</pre>

2 years, 2 months

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Punchcards

by lukaskron＠posteo.de

Hello! This is my first message to this mailing list but I think this question is well suited for here. My name is Lukas and I am currently living in Germany and I am searching for punch cards preferable with logos/universities around the world. If someone still has some of such cards laying around I would love a message of your offer (off-list). Highly appreciated as I am collecting them. Kindly Lukas

2 years, 2 months

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Video/keyboard mono cable for Sun 386i

by Stefano Sanna

Hi. I recently bought a Sun Microsystems 386i and I discovered (too late...) that monitor and keyboard are connected to the same D15 connector on the back using a "Y" cable (I had experience with other Sun workstations, this was first contact with Intel-based hardware). Unfortunately, I have not such a cable neither I was able to find any info on the web about the pinout/wiring; probably it would be possible to create the cable from scratch (assuming that no other circuitry was inside the original Y cable). Moreover, I discovered that there is more than one option for video boards (mono and color): therefore, there is more than a single Y cable to connect monitor and keyboard. Looking at the official Sun's hardware list, I found this item: 630-1621 386i video/keyboard cable but it does not specify whether it is the mono or the color cable. In any case, it seems impossible to buy it on eBay or similar. Does anybody have some information on how to rebuild it? Thank you. -s

2 years, 2 months

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Re: Video/keyboard mono cable for Sun 386i

by Stefano Sanna

[sending message again, with attachment replaced by a link: https://www.mmcc.it/resources/misc/IMG_7975_video.JPG ] Thank you Richard! To use this cable, I need to replace my video card with a color one. Please, see attached picture of the connector I have on my 386i. I suppose that finding the video card is harder then the cable itself! :-) However, this cable could be a good start for trying to do some reverse engineering of the pinouts. Since the code I found is different, I supposed that we can assume 630-1621 is the code of monochrome screen/cable. BR. -s On 30/05/24 11:47, Richard wrote: > Oh and there is this > > > > s-l400.jpg > SUN Microsystems 530-1366-01 Monitor + Keyboard Cable 13W3 Mini Din8 > /A4 8 Pin > <https://www.ebay.com.au/itm/295331844851?mkcid=16&mkevt=1&mkrid=705-154756-…> > ebay.com.au > <https://www.ebay.com.au/itm/295331844851?mkcid=16&mkevt=1&mkrid=705-154756-…> > > <https://www.ebay.com.au/itm/295331844851?mkcid=16&mkevt=1&mkrid=705-154756-…> > Which looks right > Sent from my iPhone > >> On 30 May 2024, at 19:07, Stefano Sanna via cctalk >> <cctalk(a)classiccmp.org> wrote: >> >> Hi. >> >> I recently bought a Sun Microsystems 386i and I discovered (too >> late...) that monitor and keyboard are connected to the same D15 >> connector on the back using a "Y" cable (I had experience with other >> Sun workstations, this was first contact with Intel-based hardware). >> >> Unfortunately, I have not such a cable neither I was able to find any >> info on the web about the pinout/wiring; probably it would be >> possible to create the cable from scratch (assuming that no other >> circuitry was inside the original Y cable). Moreover, I discovered >> that there is more than one option for video boards (mono and color): >> therefore, there is more than a single Y cable to connect monitor and >> keyboard. >> >> Looking at the official Sun's hardware list, I found this item: >> >> 630-1621 386i video/keyboard cable >> >> but it does not specify whether it is the mono or the color cable. In >> any case, it seems impossible to buy it on eBay or similar. >> >> Does anybody have some information on how to rebuild it? >> >> Thank you. >> -s

2 years, 2 months

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Re: Pragmatically [was: Experience using an Altair 8800 ("Personal computer" from 70s)]

by CAREY SCHUG

> On 05/28/2024 1:05 PM CDT Sellam Abraham <sellam.ismail(a)gmail.com> wrote: > > What if a corporation in 1970 purchased an IBM 360 for each of their employees for their individual personal use? Now what? > > Sellam > 1. I don't believe ANYBODY could purchase a 360. You had to lease them. 2. do you know of such a company? (with a significant number of employees, not a lone entrepreneur). I figure asking means that maybe you do. and since I believe no 360 but maybe the model 20 (not a real 360) or the model 22 would plug into household power it seems unlikely unless a tax dodge. 3. if it was one purchase order, it sounds like ONE for the personal computer tally, vs thousands for the not-personal tally. Remember we still need to have enough computers to be 10% (or negotiated percentage) of the total produced. One exception does not change everything. ----------------------- I should have repeated my other suggestion. Only computers NOT depreciated/expensed count as personal. If depreciated, it is a business computer for business purposes. to summarize any or all of the following: -- if depreciated or expensed (reducing income) it is business, otherwise personal. ** --10% of purchases (a lot counts as ONE purchase, including "100-200 per month for 3 years") must be out of household funds (per income tax filings) for and used for household education, not for earning claimed income. --by some criteria, be able to plug into private home power for a reasonable subset of the population. ** There could be tax reasons/dodges (not saying they are legal): (1) a small business could expense them immediately (vs depreciate over years) by titling them in employees' or families' names, (2) a private individual could depreciate even though not actually doing any significant amount of income earning work on them (3) would have been expensed/depreciated but not enough income to be of any advantage, (4) probably many others, ask a shady tax lawyer. --Carey

2 years, 2 months

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Re: terminology [was: First Personal Computer]

by John

From: ben <bfranchuk(a)jetnet.ab.ca> To: cctalk(a)classiccmp.org Subject: [cctalk] Re: terminology [was: First Personal Computer] > The third thing is a real OS. Nobody has one, as a personal computer. > CP/M and MSDOS does not handle IRQ's. Unix for the PDP-11 is real > operating system but not personal as it requires a admin,and a > swapping media. This an auld refrain among *nix partisans of the ESR type, but I've yet to hear someone offer up a real defense of it. Even putting aside what "handles IRQs" means here (yes, strictly speaking the IRQs on the IBM PC are handled by the BIOS and/or add-on drivers/utilties, but DOS most certainly makes use of the facilities provided,) why does that make it "not a real OS?" What does PDP-11 Unix provide which MS-DOS doesn't to make one "real" and the other not? Certainly, nothing about a single-tasking single-user text-based environment *requires* interrupt-based I/O, even if it may smooth out performance in some aspects. And there's little if any call for a security system that'd require an administrator account in such a model; if one user "owns" the machine, whatever they decide to do to it can be Considered Legitimate. Virtual-memory capability may certainly enable the user to do more than they'd otherwise be able to, but it's hard to make an argument for it as a *requirement;* even *nix can run without swap, and in point of fact DOS can be support virtual memory with a protected-mode extender. Or is it multi-tasking capability itself that makes the difference? Can't see why that should be the case; it's definitely convenient, but as one person can only be doing so much at any given time, it's also hard to see that as a *requirement.* So what, then, consitutes a Real Operating System, and why?

2 years, 2 months

6
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