Re: Crimping 68pin (HD68) Wire
Chuck,I do have the correct tool. I used the crimper I normally use for my other IDC cables but just couldn't apply enough force to get the teeth to come through the cable all the way. That's when I switch over to a table mounted vise and it couldn't provide enough pressure to close the two pieces of the crimp.I feel like alignment is very hard and critical for the HD68. The teeth need to come up through the top portion of the connector. I don't think I have seen this with other IDC connectors. Original message From: Chuck Guzis via cctalk Date: 2/15/20 2:53 PM (GMT-08:00) To: Ali via cctalk Subject: Re: Crimping 68pin (HD68) Wire On 2/15/20 2:11 PM, Ali via cctalk wrote:> Hello All,Recently I tried making some custom SCSI cable. In the past I have successfully made my own 50pin SCSI and Floppy cables with out much issue. However, I am finding it almost impossible to crimp the HD68 connectors on the cable. I have even tried a vise grip and I still couldn't get it to crimp all the way down. Anybody with some advice? Is there a trick I am missing? TiA.The correct tool helps--and lessens the possibility of damaging theconnector. Failing that, a drill press vise will apply uniformpressure.--on the business (connector pin) end, use a small block of wood.But you knew that.--Chuck
RE: VAXmate PSU Failure
> The UC3842 datasheet does show you can draw up to 20 mA from the Vref pin, > which should certainly power up a 555. But, this is a 5 V regulator, and may > not be working properly. it may be that driving several mA to the 555, E2 and > other components has cooked it over time. With the 555 removed, apply > resistors between pins 1 and 8 of the 555, and see how much load the UC3842 > can supply. I'm guessing that at 1 - 2 mA the Vref output is going to collapse, > indicating the UC3842 is "weak". If the Vref does droop, make sure the Vcc is > still well above 5 V. If so, it has to be the UC3842. If the Vcc is also drooping, > then follow the chain back to the power input to find the defective component. > It could be Q1, R27 R28, > R32 or for some reason the crowbar D19 is being fired. I just tried this with a 1K resistor I had to hand, so 5ma not 1-2ma, and the Vref droops. Vcc does not droop though, so I think the UC3842 needs to be replaced. I will try that. Incidentally, the UC3842 datasheet says that Vcc must have a short-path bypass capacitor to ground. If I socket the UC3842 is that going to be an issue? Thanks Rob
Re: Crimping 68pin (HD68) Wire
On 2/15/20 2:11 PM, Ali via cctalk wrote: > Hello All,Recently I tried making some custom SCSI cable. In the past I have > successfully made my own 50pin SCSI and Floppy cables with out much issue. > However, I am finding it almost impossible to crimp the HD68 connectors on > the cable. I have even tried a vise grip and I still couldn't get it to crimp > all the way down. Anybody with some advice? Is there a trick I am missing? > TiA. The correct tool helps--and lessens the possibility of damaging the connector. Failing that, a drill press vise will apply uniform pressure.--on the business (connector pin) end, use a small block of wood. But you knew that. --Chuck
Crimping 68pin (HD68) Wire
Hello All,Recently I tried making some custom SCSI cable. In the past I have successfully made my own 50pin SCSI and Floppy cables with out much issue. However, I am finding it almost impossible to crimp the HD68 connectors on the cable. I have even tried a vise grip and I still couldn't get it to crimp all the way down. Anybody with some advice? Is there a trick I am missing? TiA.
Re: Teac FD-54
On Sat, Feb 15, 2020, 14:38 Chuck Guzis wrote: > On 2/15/20 10:47 AM, Patrick Finnegan wrote: > > > I'm not sure why the index sensors on both are broken, but not the write > > protect notch sensors. Hopefully once the replacements arrive, replacing > > that will fix the drives. The drives look pristine on the inside. > > The biggest (and most misleading) issue with optical index sensors tends > to be dirt. The phototransistor or LED gets obscured by crud and ceases > to operate, even though electrically, it's fine. > In this case, the sensor seems to be stuck "on" as if it were receiving light all the time, so I don't think it's an alignment issue. I verified by pulling the disk out, checking the LED was working, and playing with the alignment of the sensor. I got no change in the output according to my scope. Moving the disk in and out to block/unblock the light from the write protect notch let me verify that that sensor was working correctly. > The same phenomenon accounts for many so-called "alignment" issues with > floppy drives--the track zero sensor gets crud and the position at which > the sensor is interrupted changes. It's a mistake to attempt to > re-align a drive before cleaning the sensor. In reality, most floppy > drives do not exhibit drifting alignment. > The track zero sensor works fine (I could manually move the head and get it to track back, and the drive doesn't have a spec of dust in it. As usual my stuff is the atypical case. :) Pat >
large HP DesignJet plotter needs a good home
Classic heavy duty HP Designjet 755CM C3198B in search of a new home as it's now one stop short of the e-waste people. It's large (handles a 36in roll) and has the usual DesignJet stand. I can even include some NOS ink cartridges. It would need a horizontal belt as they deteriorate even without use but otherwise in good shape; it was fully functional when I removed it from service. I'm not trying to sell it, I just hate to trash it. Not easily shippable, it's located in the Santa Cruz area - I could deliver it here in the bay area if someone wants it. Steve
Re: VAXmate PSU Failure
On 02/15/2020 12:17 PM, Rob Jarratt via cctalk wrote: A little while back I posted here because I needed help with analysing the failure of the PSU from my VAXmate. Since then I have had some comments on the reverse engineered schematic which I have now improved and which is here: https://rjarratt.files.wordpress.com/2020/02/h7270-control-pulse-width-modul ator.png The UC3842 datasheet does show you can draw up to 20 mA from the Vref pin, which should certainly power up a 555. But, this is a 5 V regulator, and may not be working properly. it may be that driving several mA to the 555, E2 and other components has cooked it over time. With the 555 removed, apply resistors between pins 1 and 8 of the 555, and see how much load the UC3842 can supply. I'm guessing that at 1 - 2 mA the Vref output is going to collapse, indicating the UC3842 is "weak". If the Vref does droop, make sure the Vcc is still well above 5 V. If so, it has to be the UC3842. If the Vcc is also drooping, then follow the chain back to the power input to find the defective component. It could be Q1, R27 R28, R32 or for some reason the crowbar D19 is being fired. Jon
Re: Teac FD-54
On 2/15/20 10:47 AM, Patrick Finnegan wrote: > I'm not sure why the index sensors on both are broken, but not the write > protect notch sensors. Hopefully once the replacements arrive, replacing > that will fix the drives. The drives look pristine on the inside. The biggest (and most misleading) issue with optical index sensors tends to be dirt. The phototransistor or LED gets obscured by crud and ceases to operate, even though electrically, it's fine. The same phenomenon accounts for many so-called "alignment" issues with floppy drives--the track zero sensor gets crud and the position at which the sensor is interrupted changes. It's a mistake to attempt to re-align a drive before cleaning the sensor. In reality, most floppy drives do not exhibit drifting alignment. --Chuck
Re: Teac FD-54
On Sat, Feb 15, 2020, 13:38 Chuck Guzis via cctalk wrote: > On 2/12/20 4:49 AM, Patrick Finnegan via cctalk wrote: > > I've got a couple of Teac FD-54B's that appear to have problems with > their > > index sensors. Does anyone have any docs for these? The internet seems to > > barely know they exist vs the FD-55, which has info everywhere. I'm > thrown > > off a bit by the 3 wire phototransistor (vs the common 2 wire ones) they > > they use, and I haven't quite disassembled it enough to figure out a > part # > > for that. > > Herb Johnson (retrotechnology) has a service manual; also look in the > Tandy 1000 service manual--ISTR that there's an FD54 techref buried > somewhere in the middle of that thing. > After more diagnosis, it looks like they're TTL level output photo detectors. They have the same looking part for the write protect notch, though that one isn't stuck high. I'm not sure why the index sensors on both are broken, but not the write protect notch sensors. Hopefully once the replacements arrive, replacing that will fix the drives. The drives look pristine on the inside. Pat >
Re: Teac FD-54
On 2/12/20 4:49 AM, Patrick Finnegan via cctalk wrote: > I've got a couple of Teac FD-54B's that appear to have problems with their > index sensors. Does anyone have any docs for these? The internet seems to > barely know they exist vs the FD-55, which has info everywhere. I'm thrown > off a bit by the 3 wire phototransistor (vs the common 2 wire ones) they > they use, and I haven't quite disassembled it enough to figure out a part # > for that. Herb Johnson (retrotechnology) has a service manual; also look in the Tandy 1000 service manual--ISTR that there's an FD54 techref buried somewhere in the middle of that thing. -Chuck
VAXmate PSU Failure
A little while back I posted here because I needed help with analysing the failure of the PSU from my VAXmate. Since then I have had some comments on the reverse engineered schematic which I have now improved and which is here: https://rjarratt.files.wordpress.com/2020/02/h7270-control-pulse-width-modul ator.png Following advice from a list member, I have been looking at the 555 and the PWM that control the switching transistor, using a bench power supply to power the PWM directly (across pins 5 and 7). When I do this, I find that Vref from the PWM, which should be 5V to power the 555, does not reach 5V. I have tried removing the 555 from the circuit, and when I do this Vref goes to the nominal 5V, once Vcc to the PWM is above 16V. However, if I put the 555 back in, then Vref only goes to 2V. I have socketed the 555 and tried with two other brand new 555 chips, the result is the same. It seems that just adding a 555 kills the Vref output of the PWM. It can't be anything else in the circuit because everything else is still in circuit when the 555 has been removed. Could the PWM be faulty? Perhaps it can't provide enough current to bring Vref up to 5V once the 555 is in the circuit? Any suggestions gratefully received. Regards Rob
Re: Sun external SMD cables
On Fri, 14 Feb 2020 at 23:43, Alan Perry via cctalk wrote: > > PS I forgot to thank Liam for offering assistance, so thanks, Liam. You're very welcome. Sorry I misunderstood and couldn't help. -- Liam Proven - Profile: https://about.me/liamproven Email: lpro...@cix.co.uk - Google Mail/Hangouts/Plus: lpro...@gmail.com Twitter/Facebook/Flickr: lproven - Skype/LinkedIn: liamproven UK: +44 7939-087884 - ČR (+ WhatsApp/Telegram/Signal): +420 702 829 053
Re: Sun external SMD cables
On 2/14/20 1:54 PM, jim stephens via cctech wrote: On 2/14/2020 6:09 AM, Alan Perry via cctalk wrote: On Feb 14, 2020, at 04:15, Liam Proven via cctalk wrote: On Thu, 13 Feb 2020 at 19:06, Alan Perry via cctalk wrote: I supplied part numbers. How can I be more specific? Oddly, some of us do not have a mental look-up table of Sun part numbers. In fact I think I can safely say that I could not identify a single cable of any form for any machine ever made by its part number. If you can, good for you. I read the label attached to the cable. I could tell you what connectors are at each end of the cable, but I couldn’t tell you how they are wired together and, having no docs on the cable or an example to check, am dependent on the part number to tell me that. alan The SCSI spec and cabling have a specific way that the conductors have to be rolled to make a round cable. Each cable type has a recommended way that signal and grounds should be paired and in what proximity in the cable. For SMD I never saw a formal spec with as much detail as the SCSI spec, and I don't know if they standardized the cabling. Mainly to speculate about whether you can use a generic 25-25 or 37-37 straight thru. I opened up the drive pedestal chassis. At the panel, a 60-pin ribbon cable is split between the two D-sub connectors, 36 (with the #1 pin) on the 37-pin D-sub and 24 on the 25-pin D-sub. The ribbon cable disappears into the chassis, but there are two 60-pin ribbon cables come out, one connected to each drive. As far as the data connectors, I can only access the connector on one drive. On the drive is a 26-pin IDC connector. The ribbon cable attached to the connector is 25-pin and each drive has it own 25-pin D-sub on the back panel. I suspect the 25-25 would be sensitive to the type of conductor pairing and fabrication would work. The 37-37 bus connector probably would work with looser electrical specs to substitute in different cabling. Also just to make things more entertaining on the Oracle site for sun hardware they are using the term "Storage Module Drive" to refer to 6g/s SAS drives installed in individual blades for a blade server system. So the term appears frequently in their online docs, and including old documents and current documents. When I was searching the Interwebs by part number, I found something that categorized the cables as SAS cables, even though the official name associated with the part number says SMD. Here's one example of that term on a page https://docs.oracle.com/cd/E19452-01/html/821-0911/gkfcf.html If I'm not far off base, I ran across two vendors who may have made the controller if they aren't sun, Interphase, and Xylogics. Also an article referred to the Sun boards as Eurocard from Xylogics. Xylogics 753. The SMD controller is a Xylogics 451. It is a Multibus card, so there is a Multibus-VME on the VME board between it and the backplane. The control connector is a 60-pin IDC to ribbon cable split between two D-sub connectors as above. The data connectors is as above, 26-pin IDCs to 25-pin ribbon to 25-pin D-sub. For grins, I tried powering up the drives. They came up and didn't make horrible noises. alan Thanks Jim But if someone, say, told me "I need some SCSI cables: a MD50 to MD68 cable, 2 × MD68 to MD68, an MD50 terminator and ideally a DB25 to MD50," then I would be able to say "yes, I have some of those". However, since Jim has been a bit more forthcoming, it sounds like I can't help you. -- Liam Proven - Profile: https://about.me/liamproven Email: lpro...@cix.co.uk - Google Mail/Hangouts/Plus: lpro...@gmail.com Twitter/Facebook/Flickr: lproven - Skype/LinkedIn: liamproven UK: +44 7939-087884 - ČR (+ WhatsApp/Telegram/Signal): +420 702 829 053
Re: Sun external SMD cables
On 2/14/2020 11:11 PM, Alan Perry via cctech wrote: On 2/14/20 1:54 PM, jim stephens via cctech wrote: On 2/14/2020 6:09 AM, Alan Perry via cctalk wrote: On Feb 14, 2020, at 04:15, Liam Proven via cctalk wrote: On Thu, 13 Feb 2020 at 19:06, Alan Perry via cctalk wrote: I supplied part numbers. How can I be more specific? Oddly, some of us do not have a mental look-up table of Sun part numbers. In fact I think I can safely say that I could not identify a single cable of any form for any machine ever made by its part number. If you can, good for you. I read the label attached to the cable. I could tell you what connectors are at each end of the cable, but I couldn’t tell you how they are wired together and, having no docs on the cable or an example to check, am dependent on the part number to tell me that. alan The SCSI spec and cabling have a specific way that the conductors have to be rolled to make a round cable. Each cable type has a recommended way that signal and grounds should be paired and in what proximity in the cable. For SMD I never saw a formal spec with as much detail as the SCSI spec, and I don't know if they standardized the cabling. Mainly to speculate about whether you can use a generic 25-25 or 37-37 straight thru. I opened up the drive pedestal chassis. At the panel, a 60-pin ribbon cable is split between the two D-sub connectors, 36 (with the #1 pin) on the 37-pin D-sub and 24 on the 25-pin D-sub. The ribbon cable disappears into the chassis, but there are two 60-pin ribbon cables come out, one connected to each drive. As far as the data connectors, I can only access the connector on one drive. On the drive is a 26-pin IDC connector. The ribbon cable attached to the connector is 25-pin and each drive has it own 25-pin D-sub on the back panel. I suspect the 25-25 would be sensitive to the type of conductor pairing and fabrication would work. The 37-37 bus connector probably would work with looser electrical specs to substitute in different cabling. Also just to make things more entertaining on the Oracle site for sun hardware they are using the term "Storage Module Drive" to refer to 6g/s SAS drives installed in individual blades for a blade server system. So the term appears frequently in their online docs, and including old documents and current documents. When I was searching the Interwebs by part number, I found something that categorized the cables as SAS cables, even though the official name associated with the part number says SMD. They used the exact same name as the SMD drives you have. But as you say they are SAS, which are the somewhat older cousins of SATA drives, and nothing to do with your dries. Here's one example of that term on a page https://docs.oracle.com/cd/E19452-01/html/821-0911/gkfcf.html If I'm not far off base, I ran across two vendors who may have made the controller if they aren't sun, Interphase, and Xylogics. Also an article referred to the Sun boards as Eurocard from Xylogics. Xylogics 753. The SMD controller is a Xylogics 451. It is a Multibus card, so there is a Multibus-VME on the VME board between it and the backplane. The control connector is a 60-pin IDC to ribbon cable split between two D-sub connectors as above. The data connectors is as above, 26-pin IDCs to 25-pin ribbon to 25-pin D-sub. The drives usually had two 60 pin IDC's one in front of the other. You'd usually put a terminator for the daisy chain of the 60 pin bus cable in the outer cable, and there was enough space between them to put the ribbon cable. They used braided cables most times I ever saw them. The radial cable had a ground plane type ribbon cable with flat parallel conductors composting the rest of the 26 pin cable. Had to have one for each drive from the controller to each drive. I was going to suggest replacing the sun mess of cables with just one 60 pin cable and a 26 pin cable, and run with one drive, but realize you probably only have the sun method of terminating the bus (60 pin) cable. it needs termination at the controller, and on the last drive. Since your system was set up with the sun connection and cabling, you don't have a standalone SMD terminator, which is a small 60 pin thingie that looks a lot lie the Single Ended SCSI terminator for the 50 pin SCSI IDC cabling arrangement. For grins, I tried powering up the drives. They came up and didn't make horrible noises. alan Thanks Jim But if someone, say, told me "I need some SCSI cables: a MD50 to MD68 cable, 2 × MD68 to MD68, an MD50 terminator and ideally a DB25 to MD50," then I would be able to say "yes, I have some of those". However, since Jim has been a bit more forthcoming, it sounds like I can't help you. -- Liam Proven - Profile: https://about.me/liamproven Email: lpro...@cix.co.uk - Google Mail/Hangouts/Plus: lpro...@gmail.com Twitter/Facebook/Flickr: lproven - Skype/LinkedIn: liamproven UK: +4
