test-drb April 2005

test-drb@ccmp.vtda.org

269 participants
730 discussions

by healyzh＠aracnet.com

Well, I had one bit of luck this morning. I was wondering if I had my System 6 install floppies for the //gs at home, and it turns out that I not only had them, BUT I had DOS and ProDOS 5.25" floppies as well. The DOS 3.3 floppy is the one with ADT on it that I used years ago. I also found a bunch of C-64 floppies as well. Things kind of went down hill from there. I managed to dig out my //gs with the SCSI adapter, and I even found the Syquest 44MB cartridge for the drive (by accident, as it was seriously separated). I need to go dig for a SCSI cable and terminator though. I've also got at least one good 5.25" and 3.5" floppy (hopefully a second of each). On the downside, while I found 1 //c, and two //c monitors, I couldn't find a single powersupply. Plus I should have at least one or two //c's more that would be in better shape. I've a feeling that I gave the //c's and PS's away (I know I gave one away). I'm really bummed on this one, as I'd prefer to have a nice small //c running. Also, I couldn't get back to the //e's (or //+ & other //gs for that matter), nor could I get to the box with all the //gs, and most of my // programing books. Now I just have to find a place to set the system up, which means cleaning up :^( On a positive note, that totally blew me away, I found my X1541 cable, though I never got close to reaching any C-64's, or their floppy drives. Still I managed to get the Amiga 500 where I can reach it easier should I want to. I came really close to bringing it home. I'm really shocked, it's been years since I've wanted to mess with any of this stuff. Zane -- -- | Zane H. Healy | UNIX Systems Administrator | | healyzh at aracnet.com (primary) | OpenVMS Enthusiast | | | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | PDP-10 Emulation and Zane's Computer Museum. | | http://www.aracnet.com/~healyzh/ |

20 years, 1 month

Televideo 950 question (and a laugh at my expense)

by msokolov＠ivan.Harhan.ORG

Jay West <jwest at classiccmp.org> wrote: > The VT220 does generate CR/LF from the enter key (and I believe that's > settable, have to check). But that means it always does, not just at the > autobaud step. And.... I've used that terminal for quite some time with TSB, > and after logging in it worked just fine. It's controlled by an ANSI control sequence. (I.e., it's in the ANSI standard and not a DEC thing, which is why so many terminals support it like you've observed.) Maybe the host system in question switches the terminal into the right mode when necessary? MS

20 years, 1 month

Televideo 950 question (and a laugh at my expense)

by jwest＠classiccmp.org

So after I got my HP 2100 access system working, I noticed that the user ports (on the 12920 mux) wouldn't work on my Televideo 950. No big deal, I had a VT100 in the "computer room" and it worked fine. I made a mental note to investigate the pinouts someday, assuming the VT100 provided a signal the 12920 mux ports were expecting.... something along those lines. Never got around to it. Reorganized my "computer room" one day... and hooked everything up to the Televideo 950 via an ABCD switchbox. Then I brought up the 21MXE access system, and it suddenly because rather irritating that the TV950 wouldn't work on the 12920 mux ports, as during the re-org the VT100 was migrated to a shelf because of the switchbox. Well, now it was a pain so I spent a good while with a breakout box trying to figure out why an "ENTER" key on the TV950 would never get a "PLEASE LOG IN" prompt, but on the VT100 it always did. I spent hours screwing around with custom pinouts, looking at the control signals and figuring out what when hi/lo and when, etc. I was confused. Then I noticed that big fat "LINE FEED" button on the TV950 keyboard. I hit enter, then linefeed, and voila! PLEASE LOG IN. This immediately struck home, as I know the Access 12920 mux uses an initial CR/LF to do an autobaud. This clearly told me that the TV950 was sending a CR, rather than CRLF when the enter key was pressed. Talk about egg on your face ;) I spent hours looking in the wrong place - vaguely analogous to forgetting to check that a device was plugged in. Ha. Ha. So anyways... many terminals I've worked with support setting the ENTER/RETURN key to generate a CR, or a CR/LF. I can't find any such setting on the Televideo 950. Is it there and I'm just missing it? Jay West

20 years, 1 month

Televideo 950 question (and a laugh at my expense)

by jwest＠classiccmp.org

Eric had written.... >> And once you're logged into TSB, I don't think you *want* linefeeds after >> each CR. Just thought of something else that makes for some confusion. The VT220 does generate CR/LF from the enter key (and I believe that's settable, have to check). But that means it always does, not just at the autobaud step. And.... I've used that terminal for quite some time with TSB, and after logging in it worked just fine. Truly odd. Jay

20 years, 1 month

small valves

by ajp166＠bellatlantic.net

> >Subject: Re: small valves > From: ard at p850ug1.demon.co.uk (Tony Duell) > Date: Sat, 23 Apr 2005 00:32:48 +0100 (BST) > To: cctalk at classiccmp.org > >I have a UK battery/mains radio that uses valves throughout (even the PSU >rectifier) and directly heated valves in the signal stages. The filaments >are in series (carefulyl ordered to get suitable cathode bias voltages), >for a total of 7.5V. The batteries were a 7.5V LT and 90V Ht pair. On >mains, there is a mains transformer, the output of which is full-wave >rectified (EZ40 IIRC). That provides the HT (B+) directly, and the >filament supply (A+?) via dropping resistor. > I have an RCA AM broadcast Battery/mains radio that I still use. Works well. The multivoltage battery though bad supplied the authentic looking cover for a box I'd made using uses NiCds to run a switchmode supply to provide the A,B and C voltages required. Runs for hours on that too. Allison Kb1gmx

20 years, 1 month

small valves and RE: OT

by ajp166＠bellatlantic.net

>Subject: Re: small valves > From: ard at p850ug1.demon.co.uk (Tony Duell) > Date: Sat, 23 Apr 2005 01:49:12 +0100 (BST) > To: cctalk at classiccmp.org > >> I have an RCA AM broadcast Battery/mains radio that I still use. >> Works well. The multivoltage battery though bad supplied the >> authentic looking cover for a box I'd made using uses NiCds >> to run a switchmode supply to provide the A,B and C voltages >> required. Runs for hours on that too. > >I'm suprised it needs a separate C supply. UK sets all used self-bias by >this time, I think. C (grid bias) batteries were not used for radios much >after the 1930 in the UK. Myself as well. The design of this radio is early 50s. I have a similar circuits from the 1960 RCA tube manual that require only A and B(HT) voltages. However this radio had a battery based on destructive examination and markings that provided 7.5V, 1.5V and 90V. So the likely case is "C" voltage or as yet unexamined posibility, a seperate heater supply for the audio output tube. Either way I implmented the power supply to provide the voltages as the battery did only from a switchmode controller and a few NiCds as they are rechargeable. I then package it and wrapped the old printed cardboard around it for realism. I might add the radio is 10" wide, 7" high and about 4" deep and as AM(MW) goes sounds decent. >The batteriers are long-since unobtainable (at least not easily). I run it >from the mains. The LT is triival to get from my bench aupply. For HT, >I've made a little PSU from common components that gives about 85V (high >enough for the set to work well). It's just a 30V transformer feeding a >voltage doubler circuit. Much easier to get a 30V transformer than >something of a higher voltage now. Sound way to go. One of the homebrew designs uses a 45V transformer out of an old printer with a doubler to 110V HT and a seperate one for the 12.6V heaters. >I must try the circuit that was in Elektor a couple of months back to get >90V from low-voltage batteries. Unfamiliar, Elektor is not seen here in USA. Back OT: Anywho valves(tubes) left the computing realm early due to size, cooling and power. The side effects were that physically small circuits for computing were hard to achieve. It also limited speed due to the amount of interconnect wiring required to get signals routed. As to rad hard, there are really two different but related problems for the engineer. One is EMF the other is ionization from high energy particles. EMP as commonly seen is lightning, a high energy pulse that causes a very fast rise and fall time magnetic field and any wires in that field recieve an induced voltages and currents. If the devices are rugged enough they survive. Tubes often qualify there, solidstate devices are often less rugged and are more likely to fail. EMP is also associated with a atomic detonation, the same magnetic effects. The other problem of high energy particles such as Beta and Gamma rays can be from relatively low energy sources and are found in the Van Allen Belt (orbital space), Space itself due to solar activity and around unshielded nuclear materials. The problems associated with radiation is ionization. In semicunductors unwanted ionization will effectively short the device by creating leakage paths in the device (ICs are more susceptable than raw transistors) and also creating small control voltages at active nodes such as the base or gate of a transistor or by depleting or creating a charge where capacitive node are used (DRAMS and microprocessors that use dynamic logic). Device that have high thresholds such as CMOS and tubes are more resistant than TTL and Nmos. It also follows that static logic built with high threshold devices tends to be more resistant. Examples of devices used in EMP risk and environments with high radiation are Tubes, core memory, CMOS micros like 1802, 80C85, 80C188, ARM in CMOS. Core is actually EMP hard and RAD hard due to the closed magnetic nature of each of those thousands of little rings though the surrounding logic has to be handled as a seperate system issue as it's often built with ICs that need protection. The common need for proven RAD (radiation) hard and EMP hard is satelites as they are exposed to radiation and EMP from a variety of sources noteably including the sun. Many Sats have been killed by EMP and/or RAD >from solar storms. Allison Kb1gmx

20 years, 1 month

Ebay: HP 82045A Thermal Paper

by marvin＠rain.org

Just in case someone needs it: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=25349&item=751032250…

20 years, 1 month

Better have a strong stomach for this...

by news＠computercollector.com

Check out all four pages in the link under this photo (from CNET): http://tinyurl.com/9e6le ----------------------------------------- Evan Koblentz's personal homepage: www.snarc.net *** Tell your friends about the (free!) Computer Collector Newsletter - 700 readers and no spam / Publishes every Monday / Write for us! - Mainframes to videogames, hardware and software, we cover it all - W: http://news.computercollector.com E: news at computercollector.com

20 years, 1 month

Altair MBL source

by rcini＠optonline.net

All: I was able to get binary copies of some Altair paper tapes but none of them came with manuals. I believe that they can be loaded with the Altair Multi-Boot Loader, which I do not have. Does anyone have a copy of the MBL manual that they can scan for me? From what I've heard, it's only about 15-20 pages. Thanks in advance. Rich

20 years, 1 month

IBM 3390s on ebay...

by pat＠computer-refuge.org

Wow, for the first time that I've ever seen, actual IBM 3390s... Items #5189150755, and 5189150713 Of course $5000 seems to me to be a bit of a high starting price... probably off the mark by about 2 orders of magnitude. Pat -- Purdue University ITAP/RCS --- http://www.itap.purdue.edu/rcs/ The Computer Refuge --- http://computer-refuge.org

20 years, 1 month

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test-drb April 2005