test-drb February 2014

test-drb@ccmp.vtda.org

191 participants
208 discussions

by dm561＠torfree.net

On Fri, 7 Feb 2014, David Gesswein wrote: > I did a little searching and some IMI units use a non ST506 interface so > without changes my unit can't deal with them. The IMI 77xx are neat > looking drives. Indeed; 8" platters, a 'real' voice coil and a transparent cover to let you watch the action. As a matter of fact this weekend I'm planning to see if I can revive a 7710. --- On Fri, 7 Feb 2014, Steven Hirsh wrote: > Corvus used the IMI 5006, 5012 and 5021H depending on the storage > capacity. From everything I can see, these are (or should be) plain > vanilla MFM drives. That's interesting; are you sure that 5021Hs are ST-412 drives? The 5021H drives that I have all have the IMI interface and almost definitely came >from the factory that way. Some of the 5 1/4" IMI drives were available in both versions for a while, with the IMI interface or the ST412 version (as well as a custom 'raw' version) and conversion kits were even available, but I always assumed that the original model numbers would be different. FWIW AFAIK their first 5 1/4" drive was the 5007, unusual in that it was in a plastic chassis and used an external optical index sensor; many fond memories of having to clean out dust and realign without losing client data... I also have an IMI interface 5018H but don't recall what its specs are. > The more I think about this, the more I think they've taken some pains to > ensure it will only work with IMI drives - maybe some sort of special > operational mode? I'd be surprised but it's certainly possible; Corvus and IMI were closely connected ever since Corvus began with an 8" 77xx-based hard drive cabinet for the Apple ][, and in fact they ultimately merged.

12 years, 2 months

WTD: ITW "Magnetic Valve" keyswitches, low profile variant

by classiccmp＠philpem.me.uk

Hi, I've just got (another!) AT&T UNIX PC keyboard to replace the one with missing keycaps and -- woe and behold -- this one has a few dead keys! For bonus points, it doesn't use the same switches as the other keyboards: it uses ITW "Magnetic Valve" keyswitches instead -- Details here: http://deskthority.net/wiki/ITW_magnetic_valve Photos here: http://deskthority.net/keyboards-f2/reverse-rubber-dome-switch-t449.html http://park8.wakwak.com/~kaineko2/keyboard/album20110107.html These switches were apparently used in Decision Data, Aydin and Devlin keyboards, and consist of two metal pins and a tiny ferrite in the top of the black keyswitch base, and a pink plastic key which houses a large chunk of ferrite. A small chunk of rubber inside the keycap forms the spring which returns the key to the "not activated" position. The problem I have is that the ferrites on several of the keys have broken in transit... with these being delightfully obscure and apparently obsolete, my chances of repairing this thing (without parts at least) are slim. Does anyone have any of these keyswitches kicking around in a spares box, or a scrap keyboard which uses these keyswitches? Thanks, -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

12 years, 2 months

Code Charts navigation added to the terminals wiki

by legalize＠xmission.com

Did you ever want to see a summary of the ESC sequences understood and emitted by a terminal? The Terminals Wiki has added a new navigation menu in the upper left to quickly see a list of code charts for various terminals. <http://terminals.classiccmp.org/wiki/index.php/Category:Code_Chart> When a code chart for a terminal exists, it is linked from the info box for that terminal. -- "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> The Computer Graphics Museum <http://ComputerGraphicsMuseum.org> The Terminals Wiki <http://terminals.classiccmp.org> Legalize Adulthood! (my blog) <http://LegalizeAdulthood.wordpress.com>

12 years, 2 months

accepting pre-orders for the S-100 Z80 CPU V2 board

by LYNCHAJ＠YAHOO.COM

Hi! We are about to do another run of our popular S-100 Bus Z80 CPU V2 board. This board can run in systems (with bus termination etc.) at up to 10MHz. Apart from all the then common features found on many older S100 Z80 boards (and being completely S-100 IEEE-696 compliant), it had an extremely clever and powerful ability to allow the Z80 to address up to 1 MG of RAM in 16K "windows" within the Z80's address space. This is described here:- http://www.s100computers.com/My%20System%20Pages/Z80%20Board/Z80%20CPU%20Boa rd.htm Its primary importance is that it can be used to address greater than 64K of RAM for CPM3 and that it can be used to load/examine 8086 code at the top of the 1MG address space. The new "V2" version of the board now has the ability to (under software control) dynamically switch between two 4K blocks of code in its onboard 28C64 EEPROM (or EPROM) yet still only occupy 4K in the Z80's 64K memory space. This in effect almost doubles the size of a possible Z80 monitor. The extra code (currently being written) will include things like directly downloading binary files from a PC into the Z80's 64K (or 8086's 1M) address space. In addition, the S-100 Z80 CPU V2 has the ability to use an external CPU clock from an external source (S-100 bus pin 66 aka NDEF3). This is essential for CPU to video synchronization for MSX compatibility particularly in games. There will be a corresponding ability to export a CPU clock signal on the next version of the S-100 VDP board although this could come from any S-100 board. Current owners of the V1 board can just switch the IC's to this new bare board. The S-100 Z80 CPU V2 PCBs will be $20 each as per the usual arrangement. Shipping in the US is $3 for a single PCB and $2 for each additional PCB. Shipping internationally is $12.75 for a single PCB and $3 for each additional PCB. This is for the bare basics USPS first class postage with no tracking or insurance. The builder assumes all risk of delivery as per usual arrangement. My preference is to sell these PCBs to vintage computer/home brew computer/classic computer hobbyists first but if there are any remaining boards I will put them on eBay. Please send a PayPal to LYNCHAJ at YAHOO.COM with the subject "S-100 Z80 CPU V2 board" and I will reserve your board(s). I need about 20 pre-orders to warrant a manufacturing run. I will post more information as it becomes available. Thanks and have a nice day! Andrew Lynch

12 years, 2 months

Papertape Source (was: Re: Request for purchase of ASR-33)

by bobvines00＠gmail.com

On Sat, 11 Jan 2014 16:14:31 -0800, "Mark J. Blair" <nf6x at nf6x.net> wrote: [snip] > > * I'm having trouble finding 1" wide paper tape for my machine. It came with a small bit of black paper tape, and I see a single expensive roll of dark-colored 1" tape on eBay. I'd like to get a few rolls of plain old oiled paper tape in 1" width with a 2" core. There are several listings for narrower tape on eBay, but I'm not seeing the 1" width that I need. I'm looking forward to filling that chad box... > > * Last, but not least, I will naturally need a suitable computer such as a PDP-8 to go with it! :) > [snip] > > -- > Mark J. Blair, NF6X <nf6x at nf6x.net> > http://www.nf6x.net/ Mark, Try westnc.com at http://www.westnc.com/paper-tape-rolls.html#tty for papertape. They have both oiled & unoiled 1-inch paper tape, but recommend the oiled tape for ASR 33s. A 1/4 case of oiled papertape (7 each 1000-foot rolls) may be affordable to you at $92 plus shipping. (And they have rolls of paper for the Teletype's printer too at $112 for a case of 12 rolls, plus shipping.) Good luck on finding a PDP-8 to go with it though. :) Bob

12 years, 2 months

coss-4

by tdk.knight＠gmail.com

anyone herd of it never been able to find any info on it anywhere its on 1inch paper tape http://www.flickr.com/photos/85758861 at N00/6109885397/in/photolist-aiUL4F-dWX6HA-9fBJJ8

12 years, 2 months

MFM emulator update

by tiggerlasv＠aim.com

> 1) Gold edge fingers increase the board cost. Would people prefer a cheaper > board with .1 headers like my wirewrap board that will need non standard > cables or proper edge connectors for the drive emulation? Well worth the extra expense, in my opinion, as long as it will hold up to repeated insertion/ejections, as already mentioned in other posts. Would it be extremely difficult to put in a set of .100 holes onto the board, a little bit behind the card-edge connectors, so that folks could add their own header, if desired? > 2) It might be possible to make the board emulate two drives. The > system would have to be setup to use daisy-chained control cable since the > board will only have one control connector and two data connectors. The second > data cable would have to be .1 header. Is this enough interest to people > to be worth trying to do? TWO drives are always better than one. ;-) Would each drive be forced to the same geometry / drive types? T

12 years, 2 months

VMS microfiche

by elson＠pico-systems.com

Just to let everyone know, the VMS Microfiche set is taken. I think I have another one at work, I will let everyone know when I get it dug out. Jon

12 years, 2 months

Sigma serial card cable for LSI-11

by glenn.f.roberts＠gmail.com

An acquaintance of mine is looking to hook up his Heath/Zenith LSI-11 system to his H/Z-29 terminal. The system has the Sigma Information Systems 400200 interface card. I found him a copy of the manual but before attempting to build his own cable he was wondering if an existing cable might be found for RS-232 operation with this card. Any ideas on a source for something like that? - Glenn

12 years, 2 months

VAX 4000-200 Boot Problem

by cctech＠beyondthepale.ie

> >I have a working VAX 4000-200 and bought a spare CPU board for it. I plugged >in the spare board and it seems to hang when starting the OS boot process. >I've included the log below. I looked through the KA660 technical reference >and couldn't find what might be hanging at this point in the boot process. >I'm assuming that I can simply boot from the same OS image as the original >CPU. > Assuming you are using VMS, no changes are required to the system disk. In fact you should be able to use the same system disk to boot any of the various different VAX processors supported by the version of VMS installed, not just a 4000. > >I compared the few jumpers on both boards and they are the same. I even >validated the EPROM contents to be the same. Is the spare CPU board bad or >is there something else I should be trying/aware of? > I guess DIA5 is the correct disk to boot from as you appear to be typing it manually at the >>> prompt rather than relying on whatever is stored in NVRAM on the replacement board which is probably incorrect. > >You can see from the >log here that it does in fact pass all it's tests. Any help would be >appreciated before I attempt to return this otherwise great looking board! > >KA660-A V3.7, VMB 2.12 >Performing normal system tests. [successful tests snipped] >Tests completed. >>>>boot dia5 >(BOOT/R5:0 DIA5) > >2.. >-CAP05$DIA5 > > >Normally at this point you get a "1..0.." and then it boots into the OS. But >with the spare board, it just hangs after the last line shown above. The >EPROMs on both boards are identical as is the board revision and all part >numbers. > I have a VAX 4000/100A but I use a SCSI disk to boot it as both my DSSI disks have died. The disk I use fails to spin up sometimes after it has been left idle for a while. When this happens, my 4000 hangs at the same point as you are seeing. There are several short buzzing noises when the disk attempts to spin and if I lift it up and give it a sharp twist at the time that it tries, it usually starts spinning and all is well. I don't know if this is also a possibility with DSSI disks but it seems plausable. Is the problem still there if you put the original board back in? Regards, Peter Coghlan.

12 years, 2 months

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test-drb February 2014