test-drb June 2020

test-drb@ccmp.vtda.org

158 participants
124 discussions

by couryhouse＠aol.com

These 2 have my vote as well.... I do not know, anyone using a text only mail reader anymore! > The one thing I would change here is removal of the restriction on attachments. > > Well, two things.. Getting rid of the cctalk/cctech split as well. On Wednesday, June 17, 2020 Rob Jarratt via cctalk <rob at jarratt.me.uk; robert.jarratt at ntlworld.com; cctalk at classiccmp.org> wrote: > -----Original Message----- > From: cctalk <cctalk-bounces at classiccmp.org> On Behalf Of Al Kossow via > cctalk > Sent: 17 June 2020 13:55 > To: cctalk at classiccmp.org > Subject: Re: Future of cctalk/cctech > > > > > I wonder what you don't like about "groups.io" Its pretty much a pure mailing > list? > > Like all of the webby time-wasters, they don't have easy to mirror zipped > archives, because they want to to spend time hovering around clicking on their > sites. > > > http://www.classiccmp.org/pipermail/cctalk/ > > > The one thing I would change here is removal of the restriction on attachments. > > Well, two things.. Getting rid of the cctalk/cctech split as well. I would agree with both of those too. Rob

3 years, 10 months

Amiga Vendors?

by healyzh＠avanthar.com

I found AmigaKit.com in the UK, are there any Amiga vendors left in the US? I need to order some parts, and not only do I not remember who I used to use in the US, I assume they?re gone. Zane

3 years, 10 months

Ancient transistor ?computer board (Peter Van Peborgh)

by peter＠vanpeborgh.eu

Sorry guys about the unusable tera-URLs. To reiterate, I have acquired this board and have trouble assigning it to a particular computer manufacturer and type: Try this for the photos: https://tinyurl.com/ydxnzh9g and https://tinyurl.com/yb6z3utv Smells of (early) 1960s transistorized. No helpful marking apart from * "GATE JJ01" on SIDE A. (components). * "C NT OL DATA" on side B (solder traces). Big transistors are Motorola "180376008". Also, any ideas what the "246 636 B" boxes are, they have four legs? Can any of you of mature years suggest anything? Many thanks, ( praise be to TinyURL), peter

3 years, 10 months

Future of cctalk/cctech

by couryhouse＠aol.com

3 years, 10 months

Was: PDP-8/A transformer hum Is: VXT-2000 stuff.

by joezatarski＠gmail.com

> > > > On 6/9/2020 11:51 AM, Glen Slick via cctalk wrote: >> On Tue, Jun 9, 2020 at 9:04 AM Bill Gunshannon via cctalk >> <cctalk at classiccmp.org> wrote: >> >> For the VXT-2000 with an H7109-B the rated voltage and current values >> are printed right on the power supply label: >> >> +5.1V, 7.81A >> +12.1V, 0.62A >> -12.1V, 0.46A >> -9V, 0.2A >> >> Fixed width character pinout diagram: >> >> +=================+ >> -9V | Yellow | Orange | +12.1V >> +--------+--------+ >> ??? | White | Black | Gnd >> +--------+--------+ >> +5.1V | Red | Blue | -12.1V >> +--------+--------+ >> +5.1V | Red | Black | Gnd >> +--------+--------+ >> Gnd | Black | Black | Gnd >> +=================+ >> >> The mystery is the White wire. The power supply label only lists 4 >> output voltages. The White wire appears to be routed to the Ethernet >> daughter board. The measured voltage appears that it might be floating >> slightly negative, somewhere around -1.5V when the Ethernet daughter >> board is installed and around -5V when it is removed. Maybe it is a >> high impedance earth ground connection? It appears to be connected to >> the shield of the Ethernet BNC, which measures around 1M-Ohm to the >> chassis ground when the power supply is disconnected from the main >> board, and around 0.75M-Ohm when the power supply is connected. >> > As long as we are talking VXT-2000, I have this on file, figure it would > be useful for future googling of the list if > this were here as well.? May be a repeat of info from an earlier post, > or maybe elsewhere. > > I didn't save the source of the info, but looks like someone named Matt > Millman did it. > > The setup is as follows: HP Envy laptop running MOP boot daemon, > connected to Lantronix LTX-C twisted pair > ethernet to AUI converter (not the same as a twisted pair MAU). This is > then connected to a cabletron coax > MAU with a 10BASE5 vampire tap. The coax runs over to another MAU, which > is connected via an AUI cable to > my VXT2000. I didn't think of it, but it would have been nice to have a > real DEC MAU on the VXT2000, I've > got several DEC h4000's I could have used. > > https://www.youtube.com/watch?v=A5T2GlAN2N4 > > http://tech.mattmillman.com/projects/10base5/ The first link is mine actually. (Hi, I'm Joe from Joe's Vax Repair and More). I have a VXT-2000 and have had it setup and booting on a few occasions. I also happened into some 10BASE5 equipment a few years back and the VXT2000 was one of the only AUI devices I had at the time. I'm not Matt Millman, but I did reference that site to find the existence of the Lantronix LTX-C and similar devices. Now that I have more AUI gear, I plan to put different gear on the 3-node AUI segment (cisco 2511 router, media converter to 10BASE2, VAXStation 3200) and move the other 10Mb equipment to a 10BASE2 segment. The whole mess will be joined to the main network via T1 on a Kentrox CSU/DSU on the 2511. You can boot the VXT2000 using MOP or BOOTP and TFTP actually. MOP was the first thing I managed to get working, but BOOTP and TFTP worked equally well once I had it set up correctly. Unfortunately my bootptab file is on a roommate's MicroVAX II... Anyway, see the links section here for the software: https://terminals-wiki.org/wiki/index.php/DEC_VXT2000 There's also theoretically OpenBSD and NetBSD support for the VXT2000, but in my experience the netboot stuff is pretty broken on VAX for whatever reason. There's at least one bug for the SGEC ethernet chip driver, and I could only get older versions of the network boot mop file to load. Of course, the older versions wouldn't support the newer kernel format, which apparently changed at some point. Or maybe I'm just doing something wrong. If the machine in question gets repaired, feel free to contact me with any questions. If you're familiar with netbooting VAX systems, it's not too hard to figure out though. I'll add that the note about the 9V supply being isolated sounds reasonable. It could be used as the supply for the built-in 10BASE2 MAU on some units. I can't confirm as my unit has 10BASET instead which has no requirement for an isolated supply.

3 years, 10 months

Schematic for DEC H7441 (not the H744!)

by bob＠jfcl.com

Is there a schematic for the H7441 regulator anywhere? There are several out there for the H744 but, although they are plug compatible, the H7441 is totally different. The H744 uses an LM723, but in the 7441 DEC appears to have rolled their own regulator using a bunch discrete parts and opamps. Bob

3 years, 10 months

Future of cctalk/cctech

by couryhouse＠aol.com

We use groups,io for the tom swift discussion group real handy to post photos, files and etc.. On Wednesday, June 17, 2020 Chris Hanson via cctalk <cmhanson at eschatologist.net; cctalk at classiccmp.org> wrote: On Jun 17, 2020, at 1:50 AM, Tor Arntsen via cctalk <cctalk at classiccmp.org> wrote: > >>>> There is also groups.io, and it has some very nice features compared to > > Please please, no groups of any kinds. They're all horrible to use. Do you mean "web forum" where you say "groups?" > A > genuine mailing list like this is infinitively easier to keep track of > and read at leisure. Can't stand groups.io. I've found the groups.io <http://groups.io/> mailing list mode to be perfectly reasonable for a number of groups I'm a part of. And it has a forum-like front end for people who insist on doing everything through a web page. ? -- Chris

3 years, 10 months

Ancient transistor ?computer board

by peter＠vanpeborgh.eu

Guys, I have acquired this board and have trouble assigning it to a particular computer manufacturer and type: https://lh3.googleusercontent.com/byRPH3wCR2aqxGX9U8BZfFTT_XtF7QCKSyVXoNmGIk UheiJ5BWqxYaCWdEshppLGYkOqUD7fl9XNeVzO_tDRKVOtbC3Js7T-pOvNUHs9MY9A36fc7dU6ro 1i7hx9Uhcfc6ukEGIdC5Ac6aTQhEFFoeWBxiI6Z24hZdvq1r6vRb4o-Lj778Wbo15hwxu0JxMuxE tcopNv0FG0_g6nUv0Eofalqu4TmgPfUWVCd4Y4LdA0pnhDRMYF5c2ASzS00TsyukCVrUyr298tjo vztVzUGEPHNL1beVCriuQIBLITaEMX3N8EBDuxpfav0vHFuyy9yfAgUI4uJB9qT6aFGEk2KplIVt yNWZf9phTdj-jLtqns9WvdA9Ur2klrk4uPzMyWg6SKTKRlpMrvbJuMnqZodzxPFPvWCG5--kVVBD KRAXW8xOTOPyxXx0xrcPifO49ni2SFYIkZgTb9d4gzvJaM8ugEb-jqHlc7uqHz5glwe4PfoN838w zMozr43veZSNHRTm9IMfON-w7xvbVufJpa_MzhuaTlKf9pvVcRIuxfhG4pMeVq7K6phhHpsKPfG5 h4BRgDSimCE8mToI35IWS3Ty8j01-6bibKH_kB-t35aIdkv7JIC-YZ1sDoguSdyk8h1xbM2d9i_U LFQYVC0oCHESgEGdqzGO3ntgwmV4khjgaQkcp2Bk-TuC7Nwrl57JI=w654-h871-no?authuser= 0 https://lh3.googleusercontent.com/HvltevPwIvyJF0qiAJR6wCAkI4lHfFGL2Gos5uoT4a qEJNFBAwJ3m6XX8E6k0m515EYgZJMaCwFGXiGiTCkxDeT396EjsbkukK3_XYqNDjfU8o3Pbtdq8z vm_q7MXShANXVFUL2wjXEbAhvBug1h42tZnxpDaxTCeNIHjqF2bgs6J_S3wCjmx538E4AuHCHxrr CqIr8yvL7AGlZXCWe8u05YNNZbIrUCYHbTtxh15hc0SwfRPzQ2U2v-pPxHs7-rx5mPpwxovbp24a CdwLBf5RRvvEZWZgyDGKG8xdF-al4kQdZMgxrVVXFMse3ee_J-QaYgALUxckGeWp2QxM4wolrd8Q Y1PqaMaTgbws5WSrOeBBBZrhmrUeL4TzZAlCA4-FqtRpoPIA339y9JRixB8Q6LlUeNsWzlqGqkvC JSCHlh_hpCXgwemhOtF4B1CLvNGs-PSZjTsnj_KOeSgeINz5Sc6TCrHmnxCcIY6D42aKMJRHZ9I9 7Z02FLsKwN6IKLxjifZvrkmEX4L8qXLbd8cuF0uf1PMjwC9WNC1_QpOmMiJOrBloG9pdrHRGvmfR RPQE7c6_HxVklEpIbxqkLmQVkKF-oM8VYS3A11tvslxiZUcvQcEhuEYhPLoqTD8PDikYhxKyVLhq S0DC-bIVBDDLeqiegQelHFjhptKwgs-0Q5mMrxvE6rdsd6-ipEf5Q=w654-h871-no?authuser= 0 Smells of (early) 1960s transistorized. No helpful marking apart from * "GATE JJ01" on SIDE A. (components). * "C NT OL DATA" on side B (solder traces). Big transistors are Motorola "180376008". Also, any ideas what the "246 636 B" boxes are, they have four legs? Can any of you of mature years suggest anything? Many thanks, peter || | | | | | | | | Peter Van Peborgh 62 St Mary's Rise Writhlington Radstock Somerset BA3 3PD UK 01761 439 234 "Our times are in God's wise and loving hands" || | | | | | | | |

3 years, 10 months

IBM vacuum tubes

by paul＠mcjones.org

Not exactly on subject, but problems designing the IBM 604 Electronic Calculating Punch due to the use of existing vacuum tube designs is discussed in section 2.4 of: Charles J. Bashe, Lyle R. Johnson, John H. Palmer, and Emerson W. Pugh IBM?s Early Computers The MIT Press, 1986 The book says Ralph Palmer set up a vacuum tube laboratory with the ability to manufacture small quantities of tubes. This helped them get credibility when they went to a vacuum tube manufacturer with a request for a design change to achieve the needed reliability for digital applications.

3 years, 10 months

Duplicate messages

by julf＠julf.com

Hi! Anyone else getting duplicate messages from this list? I get 2 copies of most (but not all) messages, with the second copy often arriving significantly later. Julf

3 years, 10 months

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test-drb June 2020