I need to bring up a 11/20 shall I use a variac!?
I need to bring up a 11/20 shall I use a variac!? added core where can I find if I decide to add to it? ed sharpe _www.smecc.org_ (http://www.smecc.org)
Re: I need to bring up a 11/20 shall I use a variac!?
I need to bring up a 11/20 shall I use a variac!? added core where can I find if I decide to add to it? ed sharpe _www.smecc.org_ (http://www.smecc.org/) (resent with address corrections)
RE: TU-58
> > TU58 's is ready to test. I tried it in a spare serial port on a VS 3100. > Result nothing. I suspect the port is 423 and the tu58 232. Actually the TU58 serial port has the differential driver and receivers used on the later serial ports. It should talk to DECs version of RS423 with no problems at all. What sofrware are you using to drive it? -tony
Memory Voltage on MicroVAX II
I finally fixed my H7864 PSU so I can now run my rtVAX 1000. However, I think the machine is damaging memory boards. I checked the ripple and 5V looks OK, but 12V looks suspicious. Is the 12V supply used by the memory? Incidentally, as I have mentioned before, I have drawn out the schematics for the H7864 PSU. The schematics are drawn illogically, with mistakes almost certainly still there, but the Primary side I think is more reasonable now. Is there a good place to post these? Regards Rob
Re: TU-58
Hi At the moment I have it connected to an old laptop running msdos and gizmos driver for same. Its showing signs of life at 38400. I have BOB in circuit and can see the commands going to it. Some times it responds and sometimes it does not. Rod On 05/12/15 12:29, tony duell wrote: TU58 's is ready to test. I tried it in a spare serial port on a VS 3100. Result nothing. I suspect the port is 423 and the tu58 232. Actually the TU58 serial port has the differential driver and receivers used on the later serial ports. It should talk to DECs version of RS423 with no problems at all. What sofrware are you using to drive it? -tony
Re: TU-58
On 2015-12-05 13:29, tony duell wrote: TU58 's is ready to test. I tried it in a spare serial port on a VS 3100. Result nothing. I suspect the port is 423 and the tu58 232. Actually the TU58 serial port has the differential driver and receivers used on the later serial ports. It should talk to DECs version of RS423 with no problems at all. Not only that, but you can normally go between 232 and 423 with no problem. I suspect there is something else wrong with the port, or the software... Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol
RE: TU-58
> > > >> TU58 's is ready to test. I tried it in a spare serial port on a VS 3100. > >> Result nothing. I suspect the port is 423 and the tu58 232. > > > > Actually the TU58 serial port has the differential driver and receivers used > > on the later serial ports. It should talk to DECs version of RS423 with no > > problems at all. > > Not only that, but you can normally go between 232 and 423 with no > problem. I suspect there is something else wrong with the port, or the > software... So do I Firstly, what are the jumpers on the TU-58 board? The default is 38400 baud, which is probably why Rod sees it doing something sometimes at that baud rate. A lot of laptop serial ports (and USB-serial converters) are marginal at best. I've had ones that won't drive the capacitance of a couple of metres of cable reliably at 4800 baud, let alone 38400 baud. If it were mine I'd be looking at exactly what was flowing into the UART on the TU58 with a logic analyser. -tony
Re: TU-58
And we have a runner.. it was set for 19.2k A quick change of config.sys and off we go. I have only one cartridge so no tape to tape Pc to tape works. So now to find one of my systems with a spare serial port R On 05/12/15 16:15, Johnny Billquist wrote: On 2015-12-05 13:29, tony duell wrote: TU58 's is ready to test. I tried it in a spare serial port on a VS 3100. Result nothing. I suspect the port is 423 and the tu58 232. Actually the TU58 serial port has the differential driver and receivers used on the later serial ports. It should talk to DECs version of RS423 with no problems at all. Not only that, but you can normally go between 232 and 423 with no problem. I suspect there is something else wrong with the port, or the software... Johnny
Re: Memory Voltage on MicroVAX II
On 12/05/2015 09:51 AM, Robert Jarratt wrote: I finally fixed my H7864 PSU so I can now run my rtVAX 1000. However, I think the machine is damaging memory boards. I checked the ripple and 5V looks OK, but 12V looks suspicious. Is the 12V supply used by the memory? I don't have my print set anymore, but I highly doubt it. I think the +/- 12 V is only used by serial comm boards, and possibly by some graphics boards. I would not be surprised if the regulation of the 12 V supplies is not very precise. Jon
RE: Memory Voltage on MicroVAX II
> -Original Message- > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon Elson > Sent: 05 December 2015 18:03 > To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off- > Topic Posts > Subject: Re: Memory Voltage on MicroVAX II > > On 12/05/2015 09:51 AM, Robert Jarratt wrote: > > I finally fixed my H7864 PSU so I can now run my rtVAX 1000. However, > > I think the machine is damaging memory boards. I checked the ripple > > and 5V looks OK, but 12V looks suspicious. Is the 12V supply used by the > memory? > I don't have my print set anymore, but I highly doubt it. I think the +/- 12 V is > only used by serial comm boards, and possibly by some graphics boards. I > would not be surprised if the regulation of the 12 V supplies is not very > precise. > > Jon There seems to be a spike on the 12V supply, surely that isn't good, even if it doesn't affect the memory? Regards Rob
Evotek Winchester Harddisk
Hi, has anyone ever heard of Evotek ET-5800 series Winchester harddisks? I wonder which interface they have. I'm looking for a replacement of a CDC FINCH 9410 and wonder if they would be a possible replacement. ET-5800: http://www.ebay.de/itm/252174622907 CDC-FINCH: http://bitsavers.org/pdf/cdc/discs/brochures/CDC_9410_Finch_Brochure_Mar81.pdf Oliver
Re: Evotek Winchester Harddisk
On 12/05/2015 10:36 AM, Oliver Lehmann wrote: Hi, has anyone ever heard of Evotek ET-5800 series Winchester harddisks? I wonder which interface they have. I'm looking for a replacement of a CDC FINCH 9410 and wonder if they would be a possible replacement. ET-5800: http://www.ebay.de/itm/252174622907 CDC-FINCH: http://bitsavers.org/pdf/cdc/discs/brochures/CDC_9410_Finch_Brochure_Mar81.pdf The Evotek 5000 series is a bog-standard ST-506/ST-412 "MFM" interface. OEM manual is on Manx: http://manx.classiccmp.org/mirror/harte/Evotek/ET-5000%20Family%20OEM%20Manual.pdf Back in 1983 I had an opportunity to play with one. Pretty interesting, but very expensive, as I recall--and not terribly reliable. --Chuck
RE: Memory Voltage on MicroVAX II
> > > There seems to be a spike on the 12V supply, surely that isn't good, even if > it doesn't affect the memory? Often a spike on a particular output of an SMPSU is caused by a high ESR capacitor on that output. It's worth checking them. FWIW, old DRAMs, up to about 16Kbit size, often used +12V and -5V as well as +5V. Later/larger DRAMs are +5V only. I doubt you'll find any of the former in a VAX after early 11/700-series. -tony
Re: Memory Voltage on MicroVAX II
On 12/05/2015 12:29 PM, Robert Jarratt wrote: -Original Message- From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon Elson Sent: 05 December 2015 18:03 To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off- Topic Posts Subject: Re: Memory Voltage on MicroVAX II On 12/05/2015 09:51 AM, Robert Jarratt wrote: I finally fixed my H7864 PSU so I can now run my rtVAX 1000. However, I think the machine is damaging memory boards. I checked the ripple and 5V looks OK, but 12V looks suspicious. Is the 12V supply used by the memory? I don't have my print set anymore, but I highly doubt it. I think the +/- 12 V is only used by serial comm boards, and possibly by some graphics boards. I would not be surprised if the regulation of the 12 V supplies is not very precise. Jon There seems to be a spike on the 12V supply, surely that isn't good, even if it doesn't affect the memory? How BIG a spike? In a lot of these power supplies, they don't regulate the "auxiliary" voltages. So, whatever power is needed to be sent to the main voltage, the aux. windings just tap off some of that energy. If the flux produces the right voltage on the +5V (with so many turns on that winding) then they put a few more turns on the 12 V windings, and assume it should track FAIRLY well. But, maybe during the power-up surge, charging all the caps on the +5 network, the +12 might surge a bit. I built my own power system on my uVAX-II system, and had separate supplies for +5 and +12 (mostly for the disk drives). One day the 12 V supply went haywire, and I had inadvertently disabled the crowbar circuit. It went up to 22 V and damaged the disk drive and blew caps and the RS-232 driver on the CPU board. The disk drive worked for another week, and then totally croaked. I ordered the parts for the serial transmitter and got it fixed fairly easily. (He he, glad I had that print set!) So, I can say that if the spike gets close to 22 V, that would be real bad. Jon
RE: Evotek Winchester Harddisk
> > The Evotek 5000 series is a bog-standard ST-506/ST-412 "MFM" interface. > OEM manual is on Manx: > > http://manx.classiccmp.org/mirror/harte/Evotek/ET-5000%20Family%20OEM%20Manual.pdf > > Back in 1983 I had an opportunity to play with one. Pretty interesting, > but very expensive, as I recall--and not terribly reliable. I've skimmed that manual and wonder why they are 'pretty interesting'. What have I missed? -tony
RE: Memory Voltage on MicroVAX II
> -Original Message- > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon Elson > Sent: 05 December 2015 19:19 > To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off- > Topic Posts > Subject: Re: Memory Voltage on MicroVAX II > > On 12/05/2015 12:29 PM, Robert Jarratt wrote: > >> -Original Message- > >> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon > >> Elson > >> Sent: 05 December 2015 18:03 > >> To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and > >> Off- Topic Posts > >> Subject: Re: Memory Voltage on MicroVAX II > >> > >> On 12/05/2015 09:51 AM, Robert Jarratt wrote: > >>> I finally fixed my H7864 PSU so I can now run my rtVAX 1000. > >>> However, I think the machine is damaging memory boards. I checked > >>> the ripple and 5V looks OK, but 12V looks suspicious. Is the 12V > >>> supply used by the > >> memory? > >> I don't have my print set anymore, but I highly doubt it. I think > >> the +/- > > 12 V is > >> only used by serial comm boards, and possibly by some graphics > >> boards. I would not be surprised if the regulation of the 12 V > >> supplies is not very precise. > >> > >> Jon > > There seems to be a spike on the 12V supply, surely that isn't good, > > even if it doesn't affect the memory? > > > > > How BIG a spike? In a lot of these power supplies, they don't regulate the > "auxiliary" voltages. So, whatever power is needed to be sent to the main > voltage, the aux. windings just tap off some of that energy. If the flux > produces the right voltage on the +5V (with so many turns on that > winding) then they put a few more turns on the 12 V windings, and assume it > should track FAIRLY well. But, maybe during the power-up surge, charging all > the caps on the +5 network, the +12 might surge a bit. > > I built my own power system on my uVAX-II system, and had separate > supplies for +5 and +12 (mostly for the disk drives). One day the 12 V supply > went haywire, and I had inadvertently disabled the crowbar circuit. It went > up to > 22 V and damaged the disk drive and blew caps and the RS-232 driver on the > CPU board. The disk drive worked for another week, and then totally > croaked. I ordered the parts for the serial transmitter and got it fixed fairly > easily. (He he, glad I had that print set!) > > So, I can say that if the spike gets close to 22 V, that would be real bad. > > Jon I would have to measure again, but I don't think it was anywhere near that big a spike. I did measure the ESR on the capacitor on that output and it seems OK, although marginally higher than the same cap on some of the other outputs, so I am thinking of replacing it anyway. As the 5V seems fine, the ripple seemed to be about 20mV (although I am going to check again), I do wonder what could be causing the memory modules to appear to be failing. I am hoping that re-seating will cure it. Regards Rob
Re: Evotek Winchester Harddisk
On 12/05/2015 11:19 AM, tony duell wrote: I've skimmed that manual and wonder why they are 'pretty interesting'. What have I missed? For the time (1982), they were larger than almost any other ST506-interfaced 5.25' drives. --Chuck
RE: Memory Voltage on MicroVAX II
> -Original Message- > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Robert > Jarratt > Sent: 05 December 2015 19:49 > To: 'General Discussion: On-Topic and Off-Topic Posts'; > gene...@classiccmp.org > Subject: RE: Memory Voltage on MicroVAX II > > > > -Original Message- > > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon > > Elson > > Sent: 05 December 2015 19:19 > > To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and > > Off- Topic Posts > > Subject: Re: Memory Voltage on MicroVAX II > > > > On 12/05/2015 12:29 PM, Robert Jarratt wrote: > > >> -Original Message- > > >> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of > > >> Jon Elson > > >> Sent: 05 December 2015 18:03 > > >> To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and > > >> Off- Topic Posts > > >> Subject: Re: Memory Voltage on MicroVAX II > > >> > > >> On 12/05/2015 09:51 AM, Robert Jarratt wrote: > > >>> I finally fixed my H7864 PSU so I can now run my rtVAX 1000. > > >>> However, I think the machine is damaging memory boards. I checked > > >>> the ripple and 5V looks OK, but 12V looks suspicious. Is the 12V > > >>> supply used by the > > >> memory? > > >> I don't have my print set anymore, but I highly doubt it. I think > > >> the +/- > > > 12 V is > > >> only used by serial comm boards, and possibly by some graphics > > >> boards. I would not be surprised if the regulation of the 12 V > > >> supplies is not very precise. > > >> > > >> Jon > > > There seems to be a spike on the 12V supply, surely that isn't good, > > > even if it doesn't affect the memory? > > > > > > > > How BIG a spike? In a lot of these power supplies, they don't > > regulate > the > > "auxiliary" voltages. So, whatever power is needed to be sent to the > > main voltage, the aux. windings just tap off some of that energy. If > > the flux produces the right voltage on the +5V (with so many turns on > > that > > winding) then they put a few more turns on the 12 V windings, and > > assume > it > > should track FAIRLY well. But, maybe during the power-up surge, > > charging > all > > the caps on the +5 network, the +12 might surge a bit. > > > > I built my own power system on my uVAX-II system, and had separate > > supplies for +5 and +12 (mostly for the disk drives). One day the 12 > > V > supply > > went haywire, and I had inadvertently disabled the crowbar circuit. > > It > went > > up to > > 22 V and damaged the disk drive and blew caps and the RS-232 driver on > > the CPU board. The disk drive worked for another week, and then > > totally croaked. I ordered the parts for the serial transmitter and > > got it fixed > fairly > > easily. (He he, glad I had that print set!) > > > > So, I can say that if the spike gets close to 22 V, that would be real > bad. > > > > Jon > > I would have to measure again, but I don't think it was anywhere near that > big a spike. I did measure the ESR on the capacitor on that output and it > seems OK, although marginally higher than the same cap on some of the > other outputs, so I am thinking of replacing it anyway. > > As the 5V seems fine, the ripple seemed to be about 20mV (although I am > going to check again), I do wonder what could be causing the memory > modules to appear to be failing. I am hoping that re-seating will cure it. > > Regards > > Rob Checked ripple again and 5V is fine, and 12V is actually not that big. Putting the memory back in, it started to work. So it just needed re-seating. Phew! It all works now, I have a working rtVAX 1000. Now it is time to find out what it can do. Regards Rob
Re: Memory Voltage on MicroVAX II
On 12/05/2015 01:49 PM, Robert Jarratt wrote: As the 5V seems fine, the ripple seemed to be about 20mV (although I am going to check again), I do wonder what could be causing the memory modules to appear to be failing. I am hoping that re-seating will cure it. Regards Rob I ran a uVAX-II for 21 years here in my house. It was HOT STUFF when I first got it in 1986! By 2007, it was the slowest computer in the house. It ran continuously during that period (at the end, it was only running a home environmental monitoring program, or I would have shut it down earlier.) Anyway, after some years of flawless operation, I started getting crashes every couple months. When it would hang, I would power down and re-seat all the boards. It seems like it was usually a failure of one of the grant chains (either interrupt or DMA) and the disk controller would not be able to transfer. Every once in a while I'd pull all the boards and vacuum out the backplane and gently vacuum off the boards. That sort of helped, maybe. The external UVII memory also had ribbon cables across the boards. Rough handling of these cables can cause intermittents. Jon
RE: Memory Voltage on MicroVAX II
> -Original Message- > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon Elson > Sent: 05 December 2015 23:40 > To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off- > Topic Posts > Subject: Re: Memory Voltage on MicroVAX II > > On 12/05/2015 01:49 PM, Robert Jarratt wrote: > > As the 5V seems fine, the ripple seemed to be about 20mV (although I > > am going to check again), I do wonder what could be causing the memory > > modules to appear to be failing. I am hoping that re-seating will cure > > it. Regards Rob > I ran a uVAX-II for 21 years here in my house. It was HOT STUFF when I first > got it in 1986! By 2007, it was the slowest computer in the house. It ran > continuously during that period (at the end, it was only running a home > environmental monitoring program, or I would have shut it down earlier.) > > Anyway, after some years of flawless operation, I started getting crashes > every couple months. When it would hang, I would power down and re-seat > all the boards. It seems like it was usually a failure of one of the grant chains > (either interrupt or DMA) and the disk controller would not be able to > transfer. Every once in a while I'd pull all the boards and vacuum out the > backplane and gently vacuum off the boards. That sort of helped, maybe. > > The external UVII memory also had ribbon cables across the boards. Rough > handling of these cables can cause intermittents. > > Jon Yes, when I took the board out I noticed that the connector of the ribbon was not fully inserted, although it seemed solid enough. So when I put it all back together, I really made sure that the board was fully seated and the ribbon cable connectors fully pressed home. I'll make doubly sure of this in future. For anyone else's reference, this led to SCBINT errors from the console firmware while trying to boot. Regards Rob
