test-drb December 2001

test-drb@ccmp.vtda.org

243 participants
1096 discussions

[PDP8-Lovers] how to clean a PDP8/A, dishwasher?

by mcguire＠neurotica.com

On December 16, Bill Bradford wrote: > > That would be something I'd be up for trying...if I can find a chunk > > of core of low enough density to trace the wiring in. There are some > > nice low-density planes on eBay right now, but they are priced WAY too > > high in my opinion. > > I've still got these two UNIBUS core planes (H215), but they're probably > better suited for use in a DEC system instead of being deconstructed. Yes...I will *not* deconstruct DEC core, unless it's nonfunctional and unrepairable. -Dave -- Dave McGuire St. Petersburg, FL "Less talk. More synthohol." --Lt. Worf

23 years, 12 months

"Geeks" and licensing

by acme_ent＠bellsouth.net

> From: Tony Duell <ard(a)p850ug1.demon.co.uk> > > Well, most of us (except for Tony) have areas that we are not expert in, or > > Whereas I'm not an expert in any area, right??? Wrong. Accept a complement, okay? ;>) > I am strongly of the opinion that you can't teach creativity. And thus > you can't teach somebody to be a good programmer or a good electronic > designer. Yes, there are things that such people need to know (and those > can be taught, but equally good programmer/designers tend to be > interested enough to teach themselves a lot of it). OTOH, methodology certainly *can* be taught. Unfortunately, though, either it isn't being taught, or the student just doesn't "get it." Some of the crap I've seen which was written by CS degree-holders has been truly mind-boggling due to a complete lack of structure or logic in the code. > So I don't think there's _any_ correlation (or at most a very weak one) > between qualifications and ability as a programmer/designer. Agreed, absolutely. > > Should programmers be licensed? Sure makes me wonder . . . > > I don't think so. I've seen enough 'qualified' people who I'd not trust > anywhere near anything I owned. I've also met a few totally unqualified > people who I'd be happy handing a toolkit to and letting them loose in my > workshop, knowing that they'd do no real damage. > > And 'licenses' almost always come from 'qualifications' :-( A test-based license is what I had in mind, but this raises all kinds of problems (such as who designs and administers the exam, etc.) so in the end it is probably better that the practitioners of the craft do the "weeding out" themselves. Personally, I'm glad to out of programming professionally, although it remains a favorite hobby of mine. I just got so tired of having to explain the difference between a "string" and a "character array" to some of these folks . . . over and over . . . I could tell stories you probably wouldn't believe, but the memory of them is causing me to lose my lunch so I think I'd better just log off . . . Glen 0/0

23 years, 12 months

[PDP8-Lovers] how to clean a PDP8/A, dishwasher?

by mcguire＠neurotica.com

On December 16, ajp166 wrote: > The older large ferrite core is easier to work with though > much slower. The bigger cores produce a larger output > when they switch but the cycle times are in the > 3-5uS range. The later is helpful for demos as nothing > is too fast. I wonder if it would be possible (and practical) to use a microcontroller, perhaps a PIC, to act as a core controller. Use the A/D and D/A hardware to handle the drive and sense stuff, and do all the timing in firmware...making it easily tweakable. That would be something I'd be up for trying...if I can find a chunk of core of low enough density to trace the wiring in. There are some nice low-density planes on eBay right now, but they are priced WAY too high in my opinion. -Dave -- Dave McGuire St. Petersburg, FL "Less talk. More synthohol." --Lt. Worf

23 years, 12 months

Is there no end

by mythtech＠Mac.com

>Well, I suppose every chip must aspire to mediocrity. :-P Ok... I guess it took another Mac user to see my point. I didn't doubt for a moment that the AMD chip was fully compatible with any other Intel compat OS or software... just that it was REALLY REALLY sad that they had to stamp it with windows propaganda as if windows was the only thing out there that mattered. -c

23 years, 12 months

[PDP8-Lovers] PDP-8/A limited function panel wiring?

by pete＠dunnington.u-net.com

On Dec 16, 14:58, Gunther Schadow wrote: > However, there are a few more issues to resolve first. The > little 16-pole ribbon cable that has DIL chip-like plug on > both ends that go into a chip-socket. That plug is bent and > pins are broken off. Seems like that happnes all the time. > Do I have to and if so how can I replace this? This cable > runs between the backplane and, I guess, the limited function > front panel. Assuming you can afford to shorten the length of the cable by the amount you'd lose by cutting off the DIL plug, it shouldn't be too hard. You can buy 16-pin IDC DIL plugs quite easily. The quick-and-dirty way to crimp one onto the cable is to take a piece of wood (metal is better but much more work) and shave it so it fits neatly between the pins, and then shave it down so it's the same depth as the pins are long. Place the cable in the plug, insert the whole lot in a smal vice and gently tighten it up. The piece of wood will prevent the pins from bending while you do this. > Do I need this, is the limited function front panel needed > at all? What's the function of the 16 lines, I assume I don't know. If you'd asked this a week or two ago, I might have been able to look it up in the PDP-8/A handbook I had on loan, but I've returned it. :-( I think you do need some of the switches, but I'm not sure. Have you looked at the print sets on some of the PDP-8 websites? David Gesswein's page at http://www.pdp8.net/query_docs/query_all.html is a good place to start. More specifically, follow the link labelled "244" from there, then "245" and you'll be able to download a 1-page diagram of the Limited Function Board. -- Pete Peter Turnbull Network Manager University of York

23 years, 12 months

OK all you applesoft experts out there

by rhudson＠cnonline.net

How can I detect end of file while reading a text file? 10 print chr$(4)"Open mytextfile" 20 print chr$(4)"read mytextfile" 30 input a$ 40 rem process process process 50 if what who how then 30 60 print chr$(4)"close mytextfile" hep me please! (trying to write a dumb line editor)

23 years, 12 months

Looking for a grundy NEWBRAIN

by GCarling＠aol.com

I have two NewBrain MD computers with all cables and software including bespoke Word Processor and Database. Two Data Recorders are also included. In addition I have a pair of different 5.25" disk drives in a single unit with the drive controller to fit to the underside of the computer. None of the equipment has been used for some time, but is packed in original boxes and complete with instruction booklets. Would be prepared to discuss offers. Area -- North East UK Graham C Website: grahamcarling.com

23 years, 12 months

irc

by Golemancd＠aol.com

anyone know the irc channel by any chance jooe

23 years, 12 months

was "how to clean".. How did they string cores

by Innfogra＠aol.com

In a message dated 12/16/01 2:54:15 PM Pacific Standard Time, rhudson(a)cnonline.net writes: > > Did a person string those cores with a needle and > "thread", or was it done by machine? > > My stepmother worked for Hughes Aircraft in LA assembling core memory by hand under a microscope. She was making 4X4 panels IIRC. This had to be in the 1960s I bet. Paxton Astoria, OR

23 years, 12 months

Troll got me (was Re: Is there no end)

by acme_ent＠bellsouth.net

> From: SUPRDAVE(a)aol.com Gee, a message from an AOL user with no HTML . . . imagine that . . . > Kwanzaa is NOT a real holiday. Okay, I'll bite: why isn't it? Glen 0/0

23 years, 12 months

"Geeks" and licensing

by mcguire＠neurotica.com

On December 15, Richard Erlacher wrote: > Well, perhaps the reason for all the meetings and other work you find > uninteresting is that it's necessary to arrive at a firm specification for what > you have to build before you go off and build it. Since the coding, compiling, > and debugging only represent about 5% of the task, the bulk of the work has to > happen sometime, and that's what the "other" stuff is. Some documentation and speficiation has to happen, sure. But most of the industry seems to have lost sight of the fact that these are *overhead tasks* that are secondary to the job of *building something*. It gives suits a reason to take home a paycheck...they can shuffle paperwork and Powerpoint bullshit all they want; it rarely contributes to the finish product. It's not an issue of my finding it "uninteresting"...I write code. That's what I do best. If I'm doing something other than writing code, I'm likely wasting my time...or worse, someone else's...because if I'm not writing code I'm probaby doing something I'm not particularly good at. I'm not trying to be argumentative here...though it may sound that way, please don't take it as such. Again I will qualify my statements as pertaining to sub-million-line development projects, not huge multi-million line behemoths. -Dave -- Dave McGuire St. Petersburg, FL "Less talk. More synthohol." --Lt. Worf

23 years, 12 months

Is there no end

by mcguire＠neurotica.com

On December 16, UberTechnoid(a)home.com wrote: > Remember the (iirc) Compaq ad. Thier 286 had a meg of static ram onboard. > The ad depicted an empty desk with two tire tracks burt into it and a > surprised user behind. Static RAM? Are you sure? I've never heard of static RAM in a PeeCee. That's neat. -Dave -- Dave McGuire St. Petersburg, FL "Less talk. More synthohol." --Lt. Worf

23 years, 12 months

Ampro Little Board questions...

by ajp166＠bellatlantic.net

From: Gene Buckle <geneb(a)deltasoft.com> >belongs with it. Does anyone have a Series 100 box that could give me >the measurements and connector orientation & location of the floppy >cable? Nothing magic. the last one I had used was from a PC. >Secondly, I don't know what "brand" SCSI controller is built into the >board. The SCSI chip seems to be an NCR 5830, but that leads me nowhere >in relation to whether or not it's an Adaptec or other model controller. >I need to know the brand because the hd formatting software needs to >know it. Your applying PC logic to it. It's is not Adaptec, i'ts just SCSI (SCS1 or II) host and the NCR5380 is one of the early and common chips used for that. The brand applies to the "other" board, what is known as a SCSI bridge board. Adaptec, Xybec, WD and other made them. You need to know what board and what drive to do the formatting. If you dont mind hacking Z80 code you can go frm an AMPRO LB with SCSI to a smaller SCSI drive (64mb or less, or the rest will be unused). Allison

23 years, 12 months

Arrrgh!! Piecemeal auction!

by bpope＠wordstock.com

People on here have talked about people on eBay taking a perfectly good working machine and selling it off piece by piece but this takes the capacitor screwdriver, soldering iron and sucker.... http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1309283581 This person? is selling 40 little plastic thingies that go under a key on the Commodore 128's keyboard along with a spring!!! Bryan Excuse while I go bang my head against a wall... Did you know if you do that for an hour you burn 150 calories?

23 years, 12 months

Should engineers be licensed (Was "Geeks")

by acme_ent＠bellsouth.net

> From: CLeyson(a)aol.com > Thanks to AOL I can't turn this feature off :-( Yes, you can! I have posted numerous messages to this list (and others) >from an AOL account in the past and never sent anything but plain text. Glen 0/0

23 years, 12 months

Should engineers be licensed (Was "Geeks")

by acme_ent＠bellsouth.net

> There's a big difference between writing code to solve problems and being > a software engineer. Designing, coding, and compiling is only 40% of the > battle. Hopefully you're also spending some time planning and testing. To me planning and testing are such obviously important parts of any development process that I didn't mention them in my original post, assuming (I hope correctly) that most everyone on this list is as old-fashioned as I am ;>) > We recently interviewed an electronics engineering graduate who didn't know > the difference between NPN and PNP transistors !! What do they teach kids > these days ?? I repeat, the "faculty" of the "institution" which issued this fellow a degree should be tarred, feathered, and run out of town on a rail. Glen 0/0

23 years, 12 months

Ampro Little Board questions...

by ajp166＠bellatlantic.net

From: Gene Buckle <geneb(a)deltasoft.com> >What is so bloody difficult about this? It's not like I'm asking >questions about quantum mechanics or something. Keerist. No one knows or has seen one. >I had two questions. The one about the SCSI interface has been answered >to my satisfaction. The second however is not only the easiest of the >two, but seeming the most difficult to answer. Seriously it's been about 14 years since I've seen one. It's length was long enough to reach with neat folds. Don't know the exact number of inches. However that FDC controller worked fine with 24 inches of cable for another project. >If you happen to own a Series 100 box, I'd be most appriciative if you'd >open it up and let me know what you find out about the cable. If you >_don't_ own one of these things, I don't want to hear from you. Period. I bet you dont turn up many Series 100 boxes. >I know how to build my own cables. I know what connectors are required. >(I even have a purpose built connector compression tool!) I'm trying to >restore this machine to _factory_ condition. Smart ass comments about >making my own cables (while simultaneously alluding that I don't know >what the fsck I'm doing) is not only not wanted, but just pisses me off. >If I'd wanted to make a generic, "will do the job" cable, I wouldn't >have asked about the original one! The Ampro cab was not common as most bought the dry board being cheaper and use whatever package was handy or one that met their spec. Even my Ampro LB manuals do not specify a length! >FYI, the machine is built for CP/M. It runs CP/M quite happily. Even >with ZCPR3. We know that too. I run on here. Allison

23 years, 12 months

[PDP8-Lovers] how to clean a PDP8/A, dishwasher?

by ajp166＠bellatlantic.net

From: Ben Franchuk <bfranchuk(a)jetnet.ab.ca> >I know that. That is why the early memory chips had separate in/out pins >to emulate core memory. Everything nowadays tends to be 8 bits with >tri-state That might have been a factor but not a requirement. The reason back then was it simplified the timing and construction of the chip. >I/O ( Grumbles here as he has a 12 bit computer and has to waste 4 bits >out of 16 ) >BTW - some say the best way to cook a fish is in the dishwasher. Use four bit wide cache parts then. Or if it's EPROM do three bytes wide and select the odd(right 12 bits) or even half(left 12bits). There are other schemes to reuse loose bits! Allison

23 years, 12 months

[PDP8-Lovers] how to clean a PDP8/A, dishwasher?

by ajp166＠bellatlantic.net

-----Original Message----- From: Ben Franchuk <bfranchuk(a)jetnet.ab.ca> > >After reading the core memory stuff I realized the what I was thinking >about was dynamic memory (16k chips) for a 2 mhz 8080 in byte. The >reason >I got confused was it used the split memory cycle read-write as core >memory. Core is one of the few destructive readout memories used. So every read has a following write to restore the data, often between data read there will be a modify cycle which means new data written back. Allison

23 years, 12 months

[PDP8-Lovers] how to clean a PDP8/A, dishwasher?

by ajp166＠bellatlantic.net

Suggestion, Pict the articles on the basic of historic design point like the Core article or some significant hardware or software. Usually that kind of article was a feature. Allison -----Original Message----- From: John Allain <allain(a)panix.com> To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org> Date: Sunday, December 16, 2001 1:42 PM Subject: Re: [PDP8-Lovers] how to clean a PDP8/A, dishwasher? >> Unfortunately these scans aren't from *my* bytes...my collection >> doesn't go back that far, as I was 7 years old in 1976...so I can't go >> scan more of 'em. :-( > >I guess I can pony up and put at least one jpegged BYTE article up >for people to see, perhaps one a month. I have no great ideas on >how to pick the titles, however. Some kind of democratic thing? > >John A. > >

23 years, 12 months

Ampro Little Board questions...

by ajp166＠bellatlantic.net

From: Richard Erlacher <edick(a)idcomm.com> >I'm curious about something here ... Was this particular system ever observed to >run as configured? I've never owned a prepackaged AMPRO box/system, so I have >no experience with them on which to base any guesses. With a SCSI drive and no >bridge, the thing should either run or not, though, and if it doesn't there's >probably a good reason. Over the years I've seen two and added hard disks to them (purchased without). If you have the right controller and drive it's an assemble the peices project. Those included some of the early SCSI drives. >I'm not in a good situation to help you out with this, at the moment, but I >could send you a bridge controller of the sort that the firmware is supposed to >recognize on its own. With that you can test the Little Board side of things. >The Little Board supports the Xebec controller as well as a number of models >from OMTI, ADAPTEC, and others. You'd have to attach an ST506/412-interfaced >drive that works properly at the other end, though. The Adaptec models I've got >are capable of either RLL or MFM, depending on which model you use and, of If you match the known configs it's pretty straightforward, if not you need to go into the bios and set up the config by hand. The latter is a bit less obvious as the Ampro BIOS for hard disk was done in three layers, one for the physical SCSI driver, then the SCSI protocal for the controller target and then hard disk interface. There are several added tables not normally seen in a CP/M bios. Those tables allow for things like assigning logical unit 3 (whatever it may be) as drive A:. As BIOS for CP/M go it's very sophisticated. Allison

23 years, 12 months

Ampro Little Board questions...

by ajp166＠bellatlantic.net

>> > From: Gene Buckle <geneb(a)deltasoft.com> >> Funny, the Ampro docs list all these various controllers and whatnot. >> The software also _asks_ what controller it is going to talk to. The >> SCSI controller is part of the LB. What would the software consider the >> onboard controller to be? NCR5380! But that's half the picture. The other half is the SCSI controller on the other end of the cable. What I meant by PC logic is that in PCs you plug in an adaptec controller or whoever and you need a driver specific to that controller. The AMPRO-LB has the onboard NCR5380 which is the controller and the software specific to that is in both the bootrom and CP/M bios. The other peice of that that does not conform to the PC standard is the other end of the 50pin SCSI cable is the "drive" and back then the drive was MFM (ST225 typically) with a Bridge adaptor to go >from SCSI to MFM and that could be done with a board made by Xybec, Adaptec or Western Digital. Now, those bridge boards did not behave exactly the same like modern SCSI drives so the "driver" had an install/init that tweeked the CP/M bios to conform as well as partition the disk for CP/M use. The CP/M Bios (and bootrom for that fact) do not query the drive for it's config like PCs. It must be hard coded into tables in the bios. The bridge controllers require this info to be pushed into them before they can access the physical drive. This is in contrast to SCSI drives that have the tables integral to themselves. FYI: CP/M supported only 8mb per logical drive so a ST225(20mb) was usually partitioned into three logical drives (for ampro that would be A, C and D). Drive B is reserved for floppy as is pseudo drive E. Drive A(physical drive 0) is always the bootable drive and can be either floppy or hard disk. The tables for logicla drives are limited to 16 logical drives (A through P) by CP/M itself and if memory serves only 10 logical hard disk partitions in the Ampro HD CP/M bios. So any drive larger than 80mb cannot be fully accessed. There are ways around the latter problem but that's a different issue. >What hard-drive are you using? If it is a SCSI drive? Is it set to >ID=0? If so, choose either Seagate or Maxtor and give that a try. I used a 45mb fujitsu. The boot roms expect it to be ID=0. >> > formatting. If you dont mind hacking Z80 code you can go frm >> > an AMPRO LB with SCSI to a smaller SCSI drive (64mb or less, >> > or the rest will be unused). >> >> I've got a 20MB SCSI drive I'm trying to use. The bootrom rev tells me >> that it's got support for the SCSI controller. What coding has to be >> done? CP/M bios which is not the boot rom. The reason for that is the Drive tables and the controller tables in the install(HDINIT) and format(HDFMT) will not work for all but a limited subset of possible drive/controller setups. The only SCSI drive directly supported was the ST157N and maybe the ST296N might work. >If you have the proper version of the HD Utilities, you should not need >to do any. > - don Only if you have a supported controller and drive, otherwise they do not help you much. Allison

23 years, 12 months

Burroughs - any information?

by mcguire＠neurotica.com

On December 14, Chad Fernandez wrote: > The Post Office still uses Unisys stuff, although, I think they may be > switching to IBM. I saw the Portage (next city over) PO had new looking > IBM stuff a few weeks back. > > Unisys had/has a govt. division of the company. The post office in Beltsville, MD just switched over to that Unisys stuff maybe 2 years ago... -Dave -- Dave McGuire St. Petersburg, FL "Less talk. More synthohol." --Lt. Worf

23 years, 12 months

[PDP8-Lovers] how to clean a PDP8/A, dishwasher?

by ajp166＠bellatlantic.net

From: Dave McGuire <mcguire(a)neurotica.com> >> Not likely as the sense voltages are quite small and the slice time >> has to just right. > > Well I wouldn't expect to connect it *directly* to the PIC...some >analog jellybeans would seem appropriate. Look at the byte article and see why something like a PIC adds little to the task. Allison

23 years, 12 months

[PDP8-Lovers] how to clean a PDP8/A, dishwasher?

by ajp166＠bellatlantic.net

> I wonder if it would be possible (and practical) to use a >microcontroller, perhaps a PIC, to act as a core controller. Use the >A/D and D/A hardware to handle the drive and sense stuff, and do all >the timing in firmware...making it easily tweakable. Not likely as the sense voltages are quite small and the slice time has to just right. > That would be something I'd be up for trying...if I can find a chunk >of core of low enough density to trace the wiring in. There are some >nice low-density planes on eBay right now, but they are priced WAY too >high in my opinion. No need to trace, they are quite regular, you can ohm them. You still need core drivers, sense amps and a dozens of diodes for current steering. Allison

23 years, 12 months

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test-drb December 2001