test-drb June 2009

test-drb@ccmp.vtda.org

233 participants
404 discussions

by ian_primus＠yahoo.com

--- On Thu, 6/18/09, Brian Lanning <brianlanning at gmail.com> wrote: > Thanks for the help. I was hoping there was a printer > repair guru on > the group. I haven't done laser printer repair since > the laserjet 2 > and 3. I was pleased to see how serviceable the fuser > assembly was. Yeah, it's definitely much nicer to swap than the older machines. The fuser, transfer roller and all the rubber rollers are all contained in a "maintainance kit", which is recommended at varying intervals depending on model. The test page should tell you the pages since last mainainence, as well as give you an overall page count, so you can get a feeling for how much use the machine has had. > Initially I thought they had run a transparency through and > melted it > to the fuser. But it's just as you're > describing. Pieces are coming > off of the fuser film. Yup. They switched from solid rollers to a flexible plastic film roller that goes over a ceramic heating element. It'll start to fail along one edge first, and sometimes a narrow strip gets torn off one edge, then you'll get weird printouts that look fine, save for an unfused band along one edge. Soon, the film just tears apart and starts jamming. The paper also gets caught on the fuser film, and jams. > The main problem I'm having is that every page jams right > before it > enters the fuser. Does this sound like the fuser or > some of the > rollers? Have you replaced the fuser yet, or is it still the flaking one? Is the paper actually jamming, or is it just stopping, and the printer reports a jam? There are various sensors in the paper path, and if the paper takes too long to get from one point to another (or if there's toner in the sensor optos), the printer simply assumes that it's jammed and stops trying. Another thing that really confuses the heck out if the printer is if the paper size is set wrong, or if one of the flags on the tray has broken off. The paper tray contains little levers that change flags on the side or back of the tray (depending on model). When you set the guides in the tray, it changes the flags on the side - this tells the printer what size paper is loaded. If one or more of the flags is broken, or the switches are faulty, the the printer thinks the tray contains another size of paper than it really does. This can also lead to "paper isn't where I think it should be, giving up" problems. The test page should tell you what size paper the machine _thinks_ it has. I'll look up the 4100 service manual and see how it's set up, it's been a while since I've worked on one (most of my customers are on different models), so my memory is a little rusty. In the status log, the paper jams will come with an error code number that can help determine the cause of the problem as well. -Ian

15 years

Printer rant

by ian_primus＠yahoo.com

--- On Thu, 6/18/09, Brian Lanning <brianlanning at gmail.com> wrote: > I agree. I should just order one now. I was > hoping to get a lot of > mileage out of the printer anyway. > You should. Those are workhorse printers. And, for reference, the "fuser flaking into bits" is a very common failure in these, but more especially the 4200/4300 series. HP hadn't quite worked out all the kinks in their film-style fusers. Something about the way the film wore over the guides causes them to fail prematurely. At least with the 4100 you shouldn't have to worry about the swing plate gear failing, that was a big problem on early 4200/4300's. Fixing that one is fun, you have to strip the whole machine down pracically. (I do a fair amount of printer repair for my job...) But, let me know if you need a part and can't find it, I should be able to get it through my parts supplier. -Ian

15 years

PDP-11 Controller needed to use a couple of RX33 drive

by tiggerlasv＠aim.com

I'm not certain of the mechanics involved, but, you shouldn't be able to trash the format of either drive, unless the Drive Select jumpers are set incorrectly. The only thing that might have an impact on this would be if you try it in a BA23 with an un-modified 4-button front panel. *Maybe* the fact that the Ready/Write Protect lines for the 2nd drive are left floating, is somehow confusing the RQDXn controller, but that seems doubtful. Those lines merely report status of the 2nd drive. The Drive Select and Head Select lines don't go anywhere near the front panel, and there are separate signal lines for drives 0, 1, 2, and 3. >From a modification standpoint, there are NO CHANGES required to the disk drive distribution panel; all of the signal lines are there, and ready to use for 2 drives. DEC sold the "upgrade" kit for 2 hard drives; it's called the BA23-UC. It consists only of a 6-button panel. This is the same 6-button panel that was shipped with later models of the MicroVax, which clearly supported 2 internal RD-series disk drives. All the 6-button panels did was to add the extra ready/write protect buttons. There is no extra logic involved. The Write Protect LIGHTS for the RX50's were deleted, as the newer RQDX3 controller doesn't provide any outputs for the floppy write protect lights. Most of this information is documented on-line, in the document "third-party disks.txt". All that need be done to the 4-button panels is to solder 2 resistors onto the boards, to pull the 2 signal lines to their appropriate logic levels. The RQDX3 only uses these signals to establish that the drive is on-line, and write-enabled. It has nothing to do which drive is selected when it goes to write. Have I trashed the format of a drive in a 2-drive BA23 configuration? Yes, I have. But only because I wasn't paying attention, and didn't set the Drive Select jumpers to "3" on both drives. Remember: The distribution panel shifts the signal lines around, and all hard drives need to be set to "3". This could easily trip you up if you weren't paying attention, as some of the drives had DS markings of 0 - 3, and some were marked 1 - 4 . . . Thus, depending on what DS settings you have, you could in theory have 2 drives responding to the same drive select signal, which could trash your format. T

15 years

PDP-11 Controller needed to use a couple of RX33 drive

by pete＠dunnington.plus.com

On 18/06/2009 08:05, Pete Turnbull wrote: > {re two hard drives in a BA23] Mine works, and I've not cut any wires. Let's dispel a few inaccuracies that have been presented about this. First of all, it *is* possible to have two hard drives in a BA23. However, it was not supported by DEC, partly because the particular drives they supported at the time drew too much power in a fully-populated system, and partly because the chassis would not then accomodate an RX50 or TK50 and would therefore not be field-maintainable (no way to load diagnostics from floppy or tape). Secondly, the RQDXE and RQDX1-E extenders are intended to provide additional connections for external drives, and are not used in a BA23 or BA123 for internal drives. I don't have one of either right now to check but I remember they're both purely passive devices. The RQDXE is M7512 and is used for an RQDX1; the RQDXE is M7513 and used for an RQDX2 or RQDX3. The card in a BA123 for internal distribution is an M9058, and is a buffered device. It's called a Signal Distribution Board, not an extender. The two systems (BA23/BA123) treat the drive selects in somewhat different ways, which is why you can't always simply take a drive configured for a BA123 and move it (successfully) into a BA23. An RQDXn controller provides four drive selects for hard drives. In a BA123 with M9058, each drive select is taken to one (and only one) of the 34-way connectors (J1 to J4) for the drives, but it's connected (unless you change jumpers) to all 4 drive select lines on that connector. However, as is usual, all the other signals are bussed to all connectors in parallel (though some are buffered separately to different connectors to reduce loading effects). This means you can (and normally do) set the drive select on each drive the same way - normally to DS3. This is analogous to the way you would set all drives to the same ID in a PC system, only there you use a twist in the cable to re-route the drive selects. Although all the signals are bussed, many (including Write Gate) are gated /in the drive/ with the drive select. Because each connector is connected to a different drive select, no two drives can be selected at the same time. However, this is not done in a BA23 distribution board, where all the bus signals are simply bussed. Normally in a BA23 you set the first hard drive to DS3, as that's the first drive select the RQDXn tries when it looks for drives. That's why the convention for the BA123 also became to set every drive to DS3. If you use an expander to connect an expansion box, again you set the first drive in the expansion box to DS3 but you set the second drive to DS4. If you add a second internal drive to a BA23, you must do the same thing: set the drive select to DS4. This is actually stated in the microPDP-11 Maintenance Manual, in more than one place. If you set two drives with the same drive select jumpering, they will both be enabled at the same time, regardless of position. Actually, you could set the second drive to any select except DS3, at least for RQDX2 and RQDX3, but you need to be aware that the RQDXn controllers use the same drive select signals for RX drives as for RD drives. In other words, it has only 4 drive select lines for all the drives connected to it, and it tests them in order DS3, DS4, DS1, DS2. You're supposed to reserve DS1 and DS2 for an RX50 if using an RQDX1. I've never tried this in a BA23 with its own distribution board, so I don't know if it actually connects all 4 drive selects. My 11/83 in a BA23 is set up exactly like this -- DU0: uses DS3 and DU1: uses DS4. It's always been this way, and has always worked. Nothing else has been modified. For the record, it has a pair of RD54 drives in it, and has been running 2.11 BSD for years. There is another gotcha, though. The RD console board on some BA23 boxes -- that's the small card just behind the front panel -- only has connections for one drive. That card has two pushbutton switches, for Write Protect and Ready, along with some very simple electronics including pullup resistors and LEDs. When the switches are open, the drive is enabled (able to go Ready) and write enabled (not Write Protected). Usually the same thing happens when the board is absent because the two signals tend to float high (though not always reliably). Each switch is arranged to short the corresponding signal to ground when pushed in. The LED on the Write Protect is connected between +5V (via a 150R resistor) and the WP switch, and lights up when the switch is pushed in (Write Protected). The LED on the Ready is fed via a transistor to invert it, so it lights up when the switch is /not/ pushed in (drive is enabled) but goes out when the signal from the RQDXn pulls the line low (as it does when it accesses the drive), or when the switch /is/ pushed in (not enabled). There are PostScript files showing the schematics of the M9058 and console boards, and the layouts and pinouts of related boards, at http://www.dunnington.u-net.com/public/RQDX/ I've just added PDF copies for the challenged. -- Pete Peter Turnbull Network Manager University of York

15 years

Printer rant

by brianlanning＠gmail.com

So I buy this lightly used "working" HP 4100n from ebay. They only allow pickups during the day, so my wife heads over to get it. I get home... the back cover is missing. Luckily they find it. She heads back over and picks it up. I put it on, plug it in... no toner cartridge. The guy hopes I'll understand. So I order a toner cartridge from ebay. I get it today, put paper in it... it jams every time. So I start taking things apart and notice that the fuser is hosed, chunks are coming out of it. So I ordered a new fuser from ebay tonight. My money is on the fuser not fixing the paper jam problem. I would never do this to someone. Am I weird?

15 years

sorry no manual but... was Re: NEC uPD7220/GDC Design Manual

by chrism3667＠yahoo.com

Sorry Andrew, I wish I had it myself (just so I could sleep w/it under my pillow and brag). I do have several boards that use the 7220. If you want digital photos of any or all, I'd be happy (but something less then joyous) to provide them. They might provide the clues you need in the absence of a bona fide manual. Included in that list would be the NEC APC vid board, the NEC APC III, and probably a few others. --- On Wed, 6/10/09, Andrew Lynch <lynchaj at yahoo.com> wrote: > From: Andrew Lynch <lynchaj at yahoo.com> > Subject: NEC uPD7220/GDC Design Manual > To: cctalk at classiccmp.org > Date: Wednesday, June 10, 2009, 8:45 PM > Hi! Does anyone have the NEC > uPD7220/GDC Design Manual? > > > > I am looking for one as part of research on building a home > brew NEC 7220 > video board. > > > > On a related but different subject if anyone is interested, > I just got the > N8VEM VDU board working (SY6545 based) and there are photos > in the N8VEM > wiki. > > > > http://n8vem-sbc.pbworks.com/browse/#view=ViewFolder&param=VDU > > > > Thanks and have a nice day! > > Andrew Lynch > >

15 years

PDP-11 Controller needed to use a couple of RX33 drive

by bqt＠softjar.se

Ethan Dicks <ethan.dicks at gmail.com> wrote: > On Sun, Jun 14, 2009 at 4:14 AM, Johnny Billquist <bqt at softjar.se> wrote: >> > >> > ...and if you wanted to use more than one hard drive >> > on the RQDX3 you also need the RQDXE, since the BA23 distribution board is buggy, and >> > can't actually connect two hard drives, even though you have two connections. >> > I think it's worth pointing out that people should never even try connecting two hard drives in a BA23. >> > You'll definitely wreck whatever contents you have on the disks if you try. > > I thought there was a way to do it, but you had to start moving drive > select jumpers around and it was still easy to get a double-select and > trash your contents. It's actually worse. The write enable signal apparently always gets to both drives no matter what else you are doing. So when you write to one drive, the other will also start writing, even if the head is moving right at that time. I've had to recover an RD53 which was destroyed that way. (Salvage as much data as I could, and then reformat the drive.) The funny thing is that DEC actually do write in the documentation that it is not permissible to have two hard drives in a BA23, but that note is not so easy to find, and if you don't have the documentation, it even easier to assume that you can, since you do have connectors for two drives. I believe it's a hardware "bug", which can't be fixed without cutting wires, and adding new ones. But maybe someone knows better here? > I remember trying to put a pair of RD52s or an RD53 and an RD52 on one > machine 20+ years ago. I also remember not succeeding. Clearly an > RQDXE would have made the job simpler (possible?), but we didn't have > one handy. The RQDXE will definitely do the trick. If your "not succeeding" just went as far as you didn't get it to work, without trashing the conents of a drive, you were lucky. Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

15 years

Vintage Computers w New Tech. was Re: Hardware Hobbyists vs. Emulator Jockeys

by christian_liendo＠yahoo.com

Yes, but I also have a Wameco QM-1A S-100 board that if I find a CPU card, I would like to get this and get that running as well. The Northstar I will keep original since it is complete with boards. The Wameco is a empty board --- On Wed, 6/17/09, Dan Roganti <ragooman at comcast.net> wrote: > From: Dan Roganti <ragooman at comcast.net> > Subject: Re: Vintage Computers w New Tech. was Re: Hardware Hobbyists vs. Emulator Jockeys > To: "On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > Date: Wednesday, June 17, 2009, 7:45 PM > > I remember you just bought a Northstar, wouldn't you > instead like to > learn how that hardware designed back then operates while > you restore > that machine ? > > =Dan > > > Christian Liendo wrote: > > That is REALLY nice.. > > Hmmmmm, I need to save $$ as I am trying to buy parts > for my S100 machines. > > > > I want this though. > > > > http://www.cpm80.com/superio.html > > > > > > > > > > --- On Wed, 6/17/09, Roger Pugh <rogpugh at mac.com> > wrote: > > > >??? > >> From: Roger Pugh <rogpugh at mac.com> > >> > >> > >> The 1541 Ultimate has audio out jack for that > authentic > >> drive head > >> banging experience! > >> > >> I have one, but yet to investigate its > capabilities. > >> > >> www.1541ultimate.net > >> > >> Roger > >> > >> > >>? ??? > > > > > >? ? ??? > >??? > > > ------------------------------------------------------------------------ > > > > > > No virus found in this incoming message. > > Checked by AVG - www.avg.com > > Version: 8.5.339 / Virus Database: 270.12.77/2184 - > Release Date: 06/17/09 17:55:00 > > > >??? >

15 years

Taking apart a Brikon 723 floppy drive analyzer

by keithvz＠verizon.net

So in my hunt to find more information on switches I want to clean/replace(that was mentioned in another thread), I took this Brian Instruments Brikon 723 floppy drive analyzer apart. I've taken my share of equipment apart, but I can't believe the size of the components inside. Can someone help me make sense of this design? I find no fewer than 4 HUGE transformers: (2) Pacific 0288 DP100-16 (1) Pacific 0288 DP100-28 (1) Pacific 0388 DP30-36 There appear to be (7) terminals on each transformer. Maybe +,-,GND on the primary AC side, and then (4) terminals on the secondary DC side?? I guess all (4) terminals would be the same voltage? I've emailed Pacific for the datasheets --- I doubt they are current products. Then, there are these huge capacitors, (8) Frako 3300uf ones. There are about 20 leds and 20 switches on the front panel, which are not easily accessible from the back side. The front panel has a half dozen 7-segment LEDs. One of the more prominent socketed chips is a Burr-Brown DAC80-CBI-V. (http://www.datasheetcatalog.org/datasheet/BurrBrown/mXrvxzt.pdf) There are a few daughter cards with a bunch of 74LS logic chips. There are other ICs that I can't get to without going deeper into the teardown. There's a decent size fan on the back of the unit for cooling. I guess I'm at a loss for the transformers. Why 4? So that you have separate stable sources of DC power so that the pull from one doesn't affect the others? Can I replace the power circuits with something smaller and newer? The transformers and caps make up easily 1/2 the total size inside the chassis and easily 75% of the weight. Thanks Keith

15 years

Vintage Computers w New Tech. was Re: Hardware Hobbyists vs. Emulator Jockeys

by christian_liendo＠yahoo.com

That is REALLY nice.. Hmmmmm, I need to save $$ as I am trying to buy parts for my S100 machines. I want this though. http://www.cpm80.com/superio.html --- On Wed, 6/17/09, Roger Pugh <rogpugh at mac.com> wrote: > From: Roger Pugh <rogpugh at mac.com> > > > The 1541 Ultimate has audio out jack for that authentic > drive head > banging experience! > > I have one, but yet to investigate its capabilities. > > www.1541ultimate.net > > Roger > >

15 years

← Newer
1
...
16
17
18
19
20
21
22
...
41
Older →

Jump to page:

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb June 2009