Re: What's the secret to LK201 leaf springs?
At 10:41 AM 12/09/2020 -0700, you wrote: >I got an LK201 recently that was a little damaged in transit. A couple of the >keycap assemblies and their corresponding leaf springs have come off. I can >see how the leaf springs fit on the little posts on the keycap assemblies, and >I can see where those snap into the board, but what I donât see is how to >get that put together and then keep it together while I turn it over and then >get it in place. > >Clearly there is some simple trick I am missing. What is it? > >Adam "a couple" ? Heh. I recently bought an old HP 1640B protocol analyzer, very cheap. Turns out some genius had 'lubricated' all the front panel button mechanisms. They are the red-bodied HP 'buckling spring' type, that are heat-staked to the PCB. The 'lubricant' had aged into something with glue-like properties. Also a bit corrosive to PCB traces. I've cut off the melted plastic dots and removed ALL the switches, then disassembled the switches. Still to be carefully cleaned. Then there's the small problem of reattaching 34 switch bodies to the PCB, without enough plastic in the studs to re-heat-stake them. I'm hoping superglue in the PCB holes may work. But the idea of UV-curing Bondic mentioned above sounds appealing. Oh, and 3 of the key switches have broken center shafts too, so I need to find some spare switches. Guy
Re: What's the secret to LK201 leaf springs?
Tony said > On Sat, Sep 12, 2020 at 6:41 PM Adam Thornton via cctalk > wrote: >> >> I got an LK201 recently that was a little damaged in transit. A couple of >> the keycap assemblies and their corresponding leaf springs have come off. I >> can see how the leaf springs fit on the little posts on the keycap >> assemblies, and I can see where those snap into the board, but what I don’t see is how to get that put together and then keep it together while I turn it over and then get it in place.>> >> Clearly there is some simple trick I am missing. What is it? > > When it was made, those posts were much longer. After fitting the leaf > springs and fitting the unit to the membrane/chassis plate, the posts > were melted and formed over to make a large 'head' that held it all > together (this is commonly called heat staking). > > My guess is that the formed over part has broken off (you might find > some little white disks of plastic, about 1/8" diameter, rattling > about inside the case). Alas I have never found a way to re-fix them. > There's not enough plastic in the housing to drill it out and fit > screws/nuts. There is no way of gluing something to the ends of the > posts that would be strong enough, > > -tony > Perhaps using a 3D printed jig, I would set up the key post in a lathe collet and drill a sub-millimetre hole through the axis. Then glue a sliver of carbon fibre rod in, lastly mill some channels a few thou deep along the outside of the post for binding with a strand of de-braided Kevlar thread to hold the end on. A tiny drop of cyanoacrylate applied with a sharp toothpick keeps the Kevlar in place. The end cap would be drilled with the same drill. I've used this CF+Kevlar method for repairing a number of things where there is not enough surface area for adhesive alone and I am sure the repairs will outlast the items I've fixed. It takes some patience and a need to set up the job reasonably carefully. Steve.
VAX 4000/300 start up / KA670 issues
Hi I've had a VAX 4000/300 sitting around for the past couple of years. The second time I tried to switch it on there was a bit pop from the power supply. The 12v module of the H7874 PSU is completely dead and despite my best efforts I have not been able to fix it. Tonight I decided to remove that module and just use the PSU to provide the 5v, with -12 and 12v supplied from external supplies. Surprisingly this worked, as long as the 12v rails are up before you turn on the H7874 (so if you have a dead H7874 you might want to try this...). After some messing around with MMJ cables and various serial adapters, I finally got some stuff printing to a terminal (I have abbreviated this slightly because I don't want to type it out. ]] KA670-A V3.4, VMB 2.12 ]] Performing normal system tests. ]] 66..65.. ... 51.. ]] 50..49.. ... 35.. ]] 34..33.. ... 19.. ]] 18..17.. ... 11.. ]] ]] ?5F 2 0F 44 07 ; SUBTEST_5F_0D, DE_SGEC.LIS ]] P1= P2= P3= P4= P5= ]] P6= P7= P8= P9=080A P10=0003 ]] r0=0054 r1=20084001 r2= r3= r4= ]] r5=1FFC r6=C001 r7= r8=4000 EPC= ]] 10.. ]] ]] ?5C 2 06 FF 0001 00 ; SUBTEST_5C_06, DE_SHAC.LIS ]] P1=0001 P2= P3= P4= P5= ]] P6= P7= P8= P9=080A P10=0003 ]] r0=0054 r1=002E r2=005C r3=20140784 r4=2005FFF8 ]] r5=20060028 r6=20065224 r7=20004000 r8= EPC= ]] 09..08..07..05..04..03.. ]] Normal operation not possible. ]] ]] >>> It allows me to type at this point but does not appear to do anything with the input. I've looked through the KA670 manual and found a listing of the error codes. 5F = SGEC (Second Generation Ethernet Controller) "loopback_type no_ram_tests" 5C = SHAC (Single Host Adapter Chip) "shac_number" I'm not sure if it is relevant but I removed the TOY battery when I got it to prevent it eating everything. I've not taken apart the console door thing but perhaps it was too late. The SGEC might refer to the ethernet controller installed on that door? If anyone is better at understanding these error messages I'd greatly appreciate any info you could give. Cheers, Aaron P.S. Apologies for the absurd footer appended by my university. You can probably ignore it... The list does not accept mail from my personal mail server for some reason. This message and any attachment are intended solely for the addressee and may contain confidential information. If you have received this message in error, please contact the sender and delete the email and attachment. Any views or opinions expressed by the author of this email do not necessarily reflect the views of the University of Nottingham. Email communications with the University of Nottingham may be monitored where permitted by law.
Re: Seeking "MEGATEK" Sun 3/4 era (?) VME Graphics accelerator information and driver
On 9/13/20 3:44 PM, Al Kossow via cctalk wrote: Like all of the specialized 80's VME boards, it is going to be pretty much impossible to find software for them today. You'll note on bitsavers there is almost no documentation on 3rd party VME boards outside of Motorola. They were so specialized, expensive, and sold in such small numbers that not even paper documentation can be found for them.
Re: Seeking "MEGATEK" Sun 3/4 era (?) VME Graphics accelerator information and driver
On 9/13/20 2:48 PM, null via cctalk wrote: There is no terminal for it. Megatek started out making caligraphic displays for DG systems those evolved into the Wizzard series. I have one with a Unibus interface. They switched to raster in the late 70s eventually moving to standalone 3D color raster terminals. The VME boards were their last gasp as a company as the graphics terminal market collapsed. Like all of the specialized 80's VME boards, it is going to be pretty much impossible to find software for them today.
Re: Seeking "MEGATEK" Sun 3/4 era (?) VME Graphics accelerator information and driver
This is a VME board with 3D acceleration, and RGB out. There is no terminal for it. Sent from NeXTMail > On Sep 13, 2020, at 13:28, Dennis Boone wrote: > > >> >> Alas I have no idea what they are or if there is hope of using them. > > Megatek built graphics terminals and I think plotters that were used in > CAD shops. Prime used them with some of their CAD offerings. Megatek > also did boards for at least DG, -11, Modcomp systems, maybe others. In > fact, some of the terminals may be based on Nova processors. The > Megagraphic line mentions a bit-slice custom processor inside. > > The Whizzard line seems to interface via RS-232, but the Megagraphic > family brochures say they had pio/dma interfaces for a variety of > minicomputers, so are probably closer to matching your board set. > > You'd be looking for the relevant terminal, I'd think. > > De
Re: Seeking "MEGATEK" Sun 3/4 era (?) VME Graphics accelerator information and driver
> Alas I have no idea what they are or if there is hope of using them. Megatek built graphics terminals and I think plotters that were used in CAD shops. Prime used them with some of their CAD offerings. Megatek also did boards for at least DG, -11, Modcomp systems, maybe others. In fact, some of the terminals may be based on Nova processors. The Megagraphic line mentions a bit-slice custom processor inside. The Whizzard line seems to interface via RS-232, but the Megagraphic family brochures say they had pio/dma interfaces for a variety of minicomputers, so are probably closer to matching your board set. You'd be looking for the relevant terminal, I'd think. De
Seeking "MEGATEK" Sun 3/4 era (?) VME Graphics accelerator information and driver
I picked up a pair (1 set) of these very neat old graphics boards. Alas I have no idea what they are or if there is hope of using them. One is a dual slot 9U VME board that has gobs of video ram all over it, including a board labeled Z buffer. The only output are (3) BNC connectors (R,G, and B) and a 50 pin connector marked P4. The other is a single slot 9UVME board with (8) 30 pin SIMM slots with 1mb SIMM in them, a couple of Weitek chips, another 50 pin connector labeled P4, jumpered with a baby backplane to the other board, and 6 led on the front. Anyone know what these are and where to get drivers? They appear to be Sun 3 era, and the boards are labeled “Sun OHC” with a megatek sticker. They do not appear to work out-of-box in my 3/260 as console devices- the Kernel does not identify them correctly. Thanks.
Re: What's the secret to LK201 leaf springs?
One thing I've tried and seems to work quite well (on another application) is UV curable plastic. The last thing I fixed was when the post holding one side of the exit paper tray broke off, and I used the UV curable plastic to fix it (still working just fine.) The trade name is Bondic, and I ran across it on a YouTube ad (first time EVER I bought something from an unknown YouTube ad!) This apparently is the same type of UV curable "glue" used by Dentists. It cures in about 4 seconds! My guess is that the formed over part has broken off (you might find some little white disks of plastic, about 1/8" diameter, rattling about inside the case). Alas I have never found a way to re-fix them. There's not enough plastic in the housing to drill it out and fit screws/nuts. There is no way of gluing something to the ends of the posts that would be strong enough, -tony
Re: What's the secret to LK201 leaf springs?
On Sat, Sep 12, 2020 at 6:41 PM Adam Thornton via cctalk wrote: > > I got an LK201 recently that was a little damaged in transit. A couple of > the keycap assemblies and their corresponding leaf springs have come off. I > can see how the leaf springs fit on the little posts on the keycap > assemblies, and I can see where those snap into the board, but what I don’t > see is how to get that put together and then keep it together while I turn it > over and then get it in place. > > Clearly there is some simple trick I am missing. What is it? When it was made, those posts were much longer. After fitting the leaf springs and fitting the unit to the membrane/chassis plate, the posts were melted and formed over to make a large 'head' that held it all together (this is commonly called heat staking). My guess is that the formed over part has broken off (you might find some little white disks of plastic, about 1/8" diameter, rattling about inside the case). Alas I have never found a way to re-fix them. There's not enough plastic in the housing to drill it out and fit screws/nuts. There is no way of gluing something to the ends of the posts that would be strong enough, -tony
