As far as the "broken track", with difficult to remove components, and the lack of an octopus with scope, an exacto knife slice of track can be used to meter suspect components without removal. A solder bridge then repairs the "service trick". As Tony suggested, watch for modifications that may have altered the track on purpose! Kevin Andres Senior Technician Engineered Protection Systems Inc Nicet # 90660 Fire Alarm Systems Level II 616 459 0281 kandres at epssecurity.com epssecurity.com -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of cctech-request at classiccmp.org Sent: Sunday, May 08, 2011 6:46 PM To: cctech at classiccmp.org Subject: cctech Digest, Vol 93, Issue 10 Send cctech mailing list submissions to cctech at classiccmp.org To subscribe or unsubscribe via the World Wide Web, visit http://www.classiccmp.org/mailman/listinfo/cctech or, via email, send a message with subject or body 'help' to cctech-request at classiccmp.org You can reach the person managing the list at cctech-owner at classiccmp.org When replying, please edit your Subject line so it is more specific than "Re: Contents of cctech digest..." Today's Topics: 1. Re: "Original" IBM PC (Tony Duell) 2. Re: Desoldering a chopper transistor (Tony Duell) 3. Re: rack mounting vintage gear (Al Kossow) 4. Re: ebay: VAXstations (Salt Lake City; I can pick up for you) (Wolfgang Eichberger) 5. RE: Desoldering a chopper transistor (dwight elvey) 6. Re: Desoldering a chopper transistor (Dave Caroline) 7. Re: Desoldering a chopper transistor (Chuck Guzis) 8. Re: Desoldering a chopper transistor (John Robertson) 9. Re: Desoldering a chopper transistor (Brent Hilpert) 10. RE: Desoldering a chopper transistor (Rob Jarratt) 11. RE: Desoldering a chopper transistor (arcarlini at iee.org) 12. IBM 3480 help (Patrick Finnegan) 13. Re: IBM 3480 help (vintagecoder at aol.com) 14. Re: IBM 3480 help (Al Kossow) 15. Re: Desoldering a chopper transistor (Geoffrey Reed) 16. Re: Desoldering a chopper transistor (Pete Turnbull) 17. Enormous lot of vintage microcomputer stuff for sale (Bloomington, IN) (Mark Meiss) 18. Re: Enormous lot of vintage microcomputer stuff for sale (Bloomington, IN) (Richard) 19. Re: Enormous lot of vintage microcomputer stuff for sale (Bloomington, IN) (Mark Meiss) 20. RE: Desoldering a chopper transistor (arcarlini at iee.org) 21. RE: Desoldering a chopper transistor (Rob Jarratt) 22. S-100 EPROM boards are here! (Andrew Lynch) 23. RE: Desoldering a chopper transistor (Chuck Guzis) 24. pdp11 CPU on S100 board? (David Griffith) 25. Re: pdp11 CPU on S100 board? (Roger Ivie) ---------------------------------------------------------------------- Message: 1 Date: Sun, 8 May 2011 18:46:59 +0100 (BST) From: ard at p850ug1.demon.co.uk (Tony Duell) Subject: Re: "Original" IBM PC To: cctalk at classiccmp.org Message-ID: <m1QJ84S-000J3yC at p850ug1> Content-Type: text/plain Indeed... I did wonder if the 5.25" refered to the diameter of the magneitc disk and that the square envelope was larger. However, I have just measured a 5.25" floppy disk with a ruler and the enveleope is 5.25" in each direction... So what 6" refers to is beyond me. (OK, you can call me cluelrdd for not knowing the size of the minifloppy disk, but at least I measurted it rather than making some silly comment...) Not that I am going to bid on it, but I wonder just how 'original' this is... To me an origianl IBM PC implies a 16K-64K motherboard. And a 63W power supply I would also claim that the expansio cards were origianl IBM ones. I wouldn't object to _ectras_ being third-party, but there should be enough IBM boards, of the types produced when the machine was made, to have a working system (that is, video card and floppy controller at least). But if, for exmaple, an MDA card has been rpelaced at some point by a Hercules card and the originial IBM MDA card is not included with the machine then that is not 'original'. -tony ------------------------------ Message: 2 Date: Sun, 8 May 2011 19:01:19 +0100 (BST) From: ard at p850ug1.demon.co.uk (Tony Duell) Subject: Re: Desoldering a chopper transistor To: cctalk at classiccmp.org Message-ID: <m1QJ8II-000J49C at p850ug1> Content-Type: text/plain Oh you will :-). I'll admit ot having lifted my fair share of tracks too. And damaged the odd bit of through-plating. You won;t normally break a track by just letting the iron rub across it. Are you sure this track break is not deliberate? Have you checked the components connected to each side of it and made sure they should be connected accordign to the schematics? -tony ------------------------------ Message: 3 Date: Fri, 06 May 2011 17:13:26 -0700 From: Al Kossow <aek at bitsavers.org> Subject: Re: rack mounting vintage gear To: cctalk at classiccmp.org Message-ID: <4DC48EA6.1040902 at bitsavers.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 5/5/11 11:21 PM, David Griffith wrote: And a good lot of stuff you got there, too. It would be nice to see if Morrow MICRONIX is in there somewhere. re. Fujitsu tape drive If someone wants one in the Bay Area, I have a complete unit I'm about to scrap. ------------------------------ Message: 4 Date: Sat, 7 May 2011 13:53:23 +0200 From: Wolfgang Eichberger <oe5ewl at gmail.com> Subject: Re: ebay: VAXstations (Salt Lake City; I can pick up for you) To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID: <BANLkTi=A171jPbG25ieck_NNJpTT4pg1JQ at mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 same here for austria. regards, wolfgang ps: can pick up and store too, if someone needs this. -- Wolfgang Eichberger - OE5EWL Operating System Collector Blog: 5ewl.blogspot.com Homepage: www.eichberger.org 2011/5/6 Pontus <pontus at update.uu.se>: ------------------------------ Message: 5 Date: Sat, 7 May 2011 06:26:01 -0700 From: dwight elvey <dkelvey at hotmail.com> Subject: RE: Desoldering a chopper transistor To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID: <SNT129-W426FD9C62B93280592E265A3820 at phx.gbl> Content-Type: text/plain; charset="iso-8859-1" Hi I thought I'd mention that you always need to refill with solder if it misses getting it all out. Try heating both sides with two irons( tough with only two hands but I've gotten good with holding the pump and iron at one side with just the one hand. You need something to clamp the board. Also, when first melting the solder, make sure the pin is free and centered in the hole. I push the lead around with the iron and solder melted until it feels right( it is a feel thing ). It seems that no matter how well it is cleared, some small bridge seems to be there. Often this can be easily broken loose with a little pressure lead with sideways pressure. Just as the lead pops, I remove the iron. The idea is to heat it just enough to make the solder start to soften but not so much as to melt it all and attach the lead someplace else. If this fails, I refill the hole with solder and try to adjust the lead again, while hot, to center it in the hole. As a last resort, I go to a friend house that manufactures burn-in boards. He has a solder pot. It is full and I just set the board on the brim of solder. I then just pull the part out. Do remember through all this, do not put pressure on the traces with the iron. Use a clean iron well tinned iron. You can't clear a partially cleared hole, you need to refill it and try again. Use bottled flux if you can get some, it helps to keep the solder surfaces fresh. Also, although many like solder wick, I'd done more damage with it then I'd like. I now only use the pump( not the small one with the yellow lever on the side. It is junk.The larger the better ). Dwight ------------------------------ Message: 6 Date: Sat, 7 May 2011 14:40:12 +0100 From: Dave Caroline <dave.thearchivist at gmail.com> Subject: Re: Desoldering a chopper transistor To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID: <BANLkTik391Az42pGyL5Ef1FGwC2UDpSm6w at mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 A few points 1. If the device is dead, or cheap, just cut it off above the board, the board is rare/delicate the device commodity and replaceable, then each leg can be got out above board, even the solder sucking process can do this for you. least board heating 2. after sucking all three, I try to jiggle each lead to check its free/break any small amount of solder left, hole has to be reasonable clear 3. with a large iron add solder to get a blob on all three, pull device out and then suck holes after 4. similar to above but rapid sliding of iron over the pins to get all melted, then pull device 5. back in the old days there were iron tips around for multi pin melting, I never found them to be too good braid never worked that well for me Dave Caroline ------------------------------ Message: 7 Date: Sat, 07 May 2011 08:33:01 -0700 From: "Chuck Guzis" <cclist at sydex.com> Subject: Re: Desoldering a chopper transistor To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID: <4DC503BD.29324.2A3F5E at cclist.sydex.com> Content-Type: text/plain; charset=US-ASCII On 7 May 2011 at 10:04, Rob Jarratt wrote: If you're going to do much repair of PCBs, a temperature-controlled iron is pretty important. I use my venerable Weller TCP iron--a time- proven design that's still in production after, what, a half-century? However, there are less-expensive imported options. A clean and well-tinned iron is vital to this kind of work. If your iron isn't tinned, the molten solder can't conduct heat to the joint and you end up spending too much time trying to get a joint to melt. If you're using a solder pump, make sure it's the big one; the little ones don't seem to be worth much. It often helps to add solder to a joint before you use the pump to suck the solder out. Once you've sucked the solder out of a joint (you should be able to see daylight through the joint), wiggle the component gently to break the bond between the lead and the PCB trace formed by any remaining solder film and it should pop right out. Others have suggested cutting the component body off the leads to reduce heat conduction away from the joint being worked on--and that's a very good suggestion. If you still don't trust yourself, you may want to look into a low- temperature solution, such as Chip-Quick, which is basically a low- temperature fusible alloy that takes solder into solution. It's quite valuable duing SMT rework (I have yet to damage a PCB using it to replace surface mount ICs), but it might also work with traditional through-hole devices. http://www.chipquikinc.com/index.htm I've got lots of desoldering braid, but I tend to use it for soldering SMT packages, rather than desoldering them. --Chuck ------------------------------ Message: 8 Date: Sat, 07 May 2011 09:14:25 -0700 From: John Robertson <pinball at telus.net> Subject: Re: Desoldering a chopper transistor To: General Discussion: On-Topic Posts Only <cctech at classiccmp.org> Message-ID: <4DC56FE1.8010300 at telus.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Pete Turnbull wrote: Also, once you have most of the solder removed from the feed through hole then you can push on the leg of the device with a small screwdriver (or the like) to try to release it from the side of the hole. Most device legs go in the hole on an angle, thus there is a tiny film of solder holding the leg to the side of the hole - sometimes on both the top and the bottom of the hole. You will feel or hear a tiny 'click' as the leg releases. Looks like this (somewhat crappy ASCII sketch) \ |\ | <--- Top of feed through hole | \ | | \ | | \| <--- Bottom of feed through hole \ <--- Leg of device So you are trying to break the top and bottom points by pushing the leg away from the side of the hole it is soldered to. If done correctly the device will then be easy to remove with only finger force - no prying with the screwdriver! Hope that makes sense! John :-#)# -- John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames) www.flippers.com "Old pinballers never die, they just flip out" ------------------------------ Message: 9 Date: Sat, 7 May 2011 10:01:54 -0700 From: Brent Hilpert <hilpert at cs.ubc.ca> Subject: Re: Desoldering a chopper transistor To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID: <0aa498f92dc635573a396ff7494972f1 at cs.ubc.ca> Content-Type: text/plain; charset=US-ASCII; format=flowed As you are just trying to isolate the device for testing, sometimes it is easier to open the circuits elsewhere to achieve the isolation. For example, if the collector goes to an offboard transformer through a connector, then that lead is easily isolated; the base is probably fed by a resistor and lifting one lead of the resistor will isolate the base. With 2 of the 3 connections to the transistor open, it is isolated for testing purposes. TO-220 packages (3 leads with tab) can be very difficult to remove in one piece when - as Pete was mentioning - the holes are to small. Some manufacturers fail to increase the drill size for the wider TO-220 pins, they can be very tight with no room to wiggle the lead to break the final solder bridge. Sometimes slightly twisting the lead might do it. Sometimes you have to rock the device up and out of the holes with several heating cycles. ------------------------------ Message: 10 Date: Sat, 7 May 2011 18:58:36 +0100 From: "Rob Jarratt" <robert.jarratt at ntlworld.com> Subject: RE: Desoldering a chopper transistor To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org> Message-ID: &lt;039201cc0ce0$651033b0$2f309b10$(a)ntlworld.com&gt; Content-Type: text/plain; charset="US-ASCII" easier to lead lead of transistor they solder have It is indeed a TO220 and I do need to test it. After sending my request I had an idea and took the board to a local jeweller, he was able to remove it for me by using a very fine drill to drill out the just the pins themselves. The contacts look to be intact and even if they are not I will be able to use wires to reconnect the transistor pins. Thanks Rob ------------------------------ Message: 11 Date: Sat, 7 May 2011 19:44:02 +0100 From: <arcarlini at iee.org> Subject: RE: Desoldering a chopper transistor To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org> Message-ID: <8730C5A328D94EE69B0E446A537D6F12 at ANTONIOPC> Content-Type: text/plain; charset="us-ascii" I'd be tempted to suggest that you pick up some scrap boards from somewhere (old TV/computer from the tip) and practise. You want to non-destructively remove this component and you've already lifted a track. I'd stop now and practise on something that doesn't matter. Removing something like a 4 pin molex power connector from a dead (recent:-)) hard drive or similar is probably the sort of difficulty you want? Antonio arcarlini at iee.org ------------------------------ Message: 12 Date: Sat, 7 May 2011 16:59:36 -0400 From: Patrick Finnegan <pat at computer-refuge.org> Subject: IBM 3480 help To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID: <201105071659.37382.pat at computer-refuge.org> Content-Type: Text/Plain; charset="us-ascii" I'm attempting to figure out an error code on my IBM 3480-B22 drive, and was wondering if anyone had access to a manual listing error codes for the drives. I seem to have a "logic" manual, but that's not particularly helpful yet. The code the drive displays, immediately after start-up is "CHK 38". Pat -- Patrick Finnegan ------------------------------ Message: 13 Date: Sat, 7 May 2011 21:51:31 +0000 From: vintagecoder at aol.com Subject: Re: IBM 3480 help To: cctalk at classiccmp.org Message-ID: <201105072151.p47LpZOo009529 at imr-ma01.mx.aol.com> Content-Type: text/plain; charset=US-ASCII That's out of my area but a quick check of the 3490 manuals I could find (couldn't find any relevant 3480 doc) does not look good. It says this is a "call your service rep" type of error- the CHK XX codes are apparently undocumented, at least for 3490s. If you can't find a 3480 guide on bitsavers (I just checked and couldn't find one) then this may or may not be worthwhile: http://www.fujitsu.com/downloads/COMP/fcpa/tapes/m2488ce_prod-guide.pdf The only reason I suggest it is Fujitsu has some history of ripping off IBM (they did it with several OS versions and paid over 800 million USD in a settlement) and compatible-hardware manufacturers often try to keep the same error codes to make pubs easier (also by ripping off IBM), so maybe just maybe they are using the same codes as the 3480/90 tape subsystem. See appendix E. for the code listings. Nice piece of hardware btw. IBM's marketing materials say "The A22 control unit is priced at $65,430, and the B22 tape unit, which contains two tape drives, sells for $43,120." Good luck and post back if you find anything. If you don't get any answers will need to subscribe or nobody will see your posts) and the yahoo hercules groups) email me offline and I'll see if I can find anything. -- +------------------------------------------------------------------------+ | Vintage Coder America Online Com ivagntrpbqre at nby.pbz <ROT13> | | | | Collecting: DOS assemblers, compilers, books, and related doc, | | software and doc for IBM S/360 through OS/390. | | | | Wanted: Ada 95 compilers for MVS/ESA and Solaris (Sparc). | | | |---------------------------------------+--------------------------------| | Powered by Slackware 64 & Solaris 10 | Powered by Hercules | |=======================================+================================| | PGP Key 4096R 0x1CB84BEFC73ACB32 Encrypted email preferred | | PGP Fingerprint 5C1C 3AEB A7B2 E6F7 34A0 2870 1CB8 4BEF C73A CB32 | +------------------------------------------------------------------------+ ------------------------------ Message: 14 Date: Sat, 07 May 2011 15:10:13 -0700 From: Al Kossow <aek at bitsavers.org> Subject: Re: IBM 3480 help To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Message-ID: <4DC5C345.2090008 at bitsavers.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 5/7/11 1:59 PM, Patrick Finnegan wrote: There are about 8 books in the maint set, I'll see about getting them on line. It was also sold as the DEC TA90/E. I have a couple of volumes up under dec/magtape/ta90 ------------------------------ Message: 15 Date: Sat, 07 May 2011 15:27:13 -0700 From: Geoffrey Reed <geoffr at zipcon.net> Subject: Re: Desoldering a chopper transistor To: cctalk <cctalk at classiccmp.org> Message-ID: <C9EB1551.42C11%geoffr at zipcon.net> Content-Type: text/plain; charset="US-ASCII" On 5/7/11 11:44 AM, "arcarlini at iee.org" <arcarlini at iee.org> wrote: I'd second that.. And use a good de-soldering tool. I use a Hakko 808 desoldering gun. My hot air rework station has an option for a desoldering attachment but the gun is serving me well. Just change the flux filter regularly and clean it out well. ------------------------------ Message: 16 Date: Sun, 08 May 2011 00:55:54 +0100 From: Pete Turnbull <pete at dunnington.plus.com> Subject: Re: Desoldering a chopper transistor To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Message-ID: <4DC5DC0A.9020207 at dunnington.plus.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 07/05/2011 18:58, Rob Jarratt wrote: Ah, that ought to be doable with a 40W iron. When I described using my 100W Weller, I was thinking of bigger stuff with metal cans! I hope those holes weren't plated-through ;-) -- Pete Peter Turnbull Network Manager University of York ------------------------------ Message: 17 Date: Sat, 7 May 2011 18:09:05 -0700 From: Mark Meiss <chaosotter76 at gmail.com> Subject: Enormous lot of vintage microcomputer stuff for sale (Bloomington, IN) To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID: <BANLkTimPW3gPjqQPYcx52XiV1sfPdPDaSg at mail.gmail.com> Content-Type: text/plain; charset=windows-1252 Hello to the cctalk list after a long absence! My wife and I own a small business specializing in vintage computers and electronics, especially 1980s microcomputers and game consoles. We?re in the process of moving from Bloomington, Indiana, out to California, and as part of that move, all of our inventory has to go! Because we are anxious to complete our move quickly, we need to sell everything as a single bulk lot. If you?re a fan of the technology or looking to start your own related business, this is a chance to acquire a mother lode of great old stuff. There are some real treasures included -- we hope that you?ll be able to give these computers a good home. Included are almost 100 systems (Apple, Atari, Commodore, TI, Sinclair, and more); thousands of disks, tapes, and cartridges; over a thousand books and magazines; electronics test equipment; and more. The complete list of stuff is available at http://bit.ly/izaYpw ( https://docs.google.com/document/pub?id=1JS2fRLSfeOoI27Otf-Zhkl1f84WNZQHwM-… ) I can be contacted by email at squunkin at gmail.com, or leave a message on our Google Voice number at (408) 676-6467<https://www.google.com/voice/b/2?pli=1#phones>and I?ll get back to you. (Serious offers only, please -- and feel free to pass the word along to any interested friends!) The sale will go to the best offer from the most reasonable person as quickly as we can manage it. Here are the basic terms and conditions: - We must sell as a single lot and cannot split off individual items. This is not negotiable -- I?m in California, and the inventory is stored in Indiana. (Obviously, we can?t handle returns either.) - This is a LOT of stuff; you will certainly need a U-Haul track or the like. (I?m not a pro at this, but I?d estimate a 20? truck.) - Once the sale has been arranged, I?ll make a trip back to Indiana to help you load up your truck: you?re not on your own. This makes it very important to me to establish a firm pick-up date. I can be flexible about the day of the week. - We cannot guarantee the condition of individual items and must sell as-is: most of this stuff is at least 20 years old. We have always tried to test new equipment as it arrives, and most of the media have been kept in a controlled environment. - Southern Indiana is humid and subject to flooding, and there is a chance that some items may have some moisture damage. If we discover in the process of loading that any items of particular interest to you are damaged, we can adjust the final sale price accordingly. Please let us know about those items in advance! - The list of items we?ve compiled is not exhaustive, but represents a large sample from our inventory database. There?s more. - We currently have around 3-4 dozen WYSE and Falco terminals available, most of which power on. Please let us know ASAP if you want them included -- otherwise, they?ll be heading to recycling on May 14th. - If you have any questions, please ask! I will try to respond to every enquiry with 24 hours. ------------------------------ Message: 18 Date: Sat, 07 May 2011 22:06:52 -0600 From: Richard <legalize at xmission.com> Subject: Re: Enormous lot of vintage microcomputer stuff for sale (Bloomington, IN) To: cctalk <cctalk at classiccmp.org> Message-ID: <E1QIvGe-0007Iu-6j at shell.xmission.com> In article <BANLkTimPW3gPjqQPYcx52XiV1sfPdPDaSg at mail.gmail.com>, Mark Meiss <chaosotter76 at gmail.com> writes: Good luck with that. Pretty much everything listed there is obtainable incrementally and few people are interested in buying huge lots of things when they could obtain them incrementally. I understand its what's easiest for you, but given the economy its probably better to cater to the buyer. -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/> Legalize Adulthood! <http://legalizeadulthood.wordpress.com> ------------------------------ Message: 19 Date: Sat, 7 May 2011 23:51:17 -0700 From: Mark Meiss <chaosotter76 at gmail.com> Subject: Re: Enormous lot of vintage microcomputer stuff for sale (Bloomington, IN) To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID: <BANLkTik=WNawSCVKv_FD5t3ybq2tVa6RXg at mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Well, yes, I imagine that few people are, but we're hoping for exactly one, and here seems likelier a place than most. (Not to mention that Bloomington isn't so far from Dayton, and the Hamvention is coming right up in a few weeks.) We're not looking for top dollar (the move is a good move), but a chance to try to transfer these things en masse to somebody with an understanding of what they are -- hence the desire to avoid eBay if possible. On Sat, May 7, 2011 at 9:06 PM, Richard <legalize at xmission.com> wrote: ------------------------------ Message: 20 Date: Sun, 8 May 2011 10:47:47 +0100 From: <arcarlini at iee.org> Subject: RE: Desoldering a chopper transistor To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org> Message-ID: <865E15B734024AA98E807E829C8F7704 at ANTONIOPC> Content-Type: text/plain; charset="us-ascii" Tony Duell [ard at p850ug1.demon.co.uk] wrote: I've lifted my fair share of tracks (possibly more, just natural greed I guess). Once or twice I've had to put down wire to make up for my clumsiness, although mostly I've lifted tracks on scrap that I don't care about (I just wanted whatever component it might have been). Antonio arcarlini at iee.org ------------------------------ Message: 21 Date: Sun, 8 May 2011 10:57:39 +0100 From: "Rob Jarratt" <robert.jarratt at ntlworld.com> Subject: RE: Desoldering a chopper transistor To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org> Message-ID: &lt;03ed01cc0d66$5f623a40$1e26aec0$(a)ntlworld.com&gt; Content-Type: text/plain; charset="US-ASCII" guess). just wanted And just for the record, I have not actually lifted a track. The track damage is strange and I am not entirely convinced it was me because it is a little distance from the pin, perhaps 5mm away and it is a break in the track. It looks like I could have let the iron slip across it, but I don't recall that happening, and the break seems too wide for the size of bit I was using. Is it possible there might have been a latent track defect that the heat from the iron revealed? Regards Rob ------------------------------ Message: 22 Date: Sun, 8 May 2011 08:05:54 -0400 From: "Andrew Lynch" <lynchaj at yahoo.com> Subject: S-100 EPROM boards are here! To: <cctalk at classiccmp.org> Message-ID: <6B4661ED29914CC8B690BC223940C2F3 at andrewdesktop> Content-Type: text/plain; charset="us-ascii" Hi! The S-100 EPROM PCBs have arrived! These are updated respins of the S-100 EPROM board from last summer with minor corrections and improvements. The S-100 EPROM board supports a wide variety of EPROMs, EEPROMs, FLASH memories, and Static RAMs in 8 or 16 bit modes. It supports many common 28 pin and 32 pin chips. More information is available at John's S100computers.com website here: http://s100computers.com/My%20System%20Pages/PROM%20Board/PROM%20Board.htm The board is $20 plus $3 shipping in the US and $6 elsewhere. Please send a PayPal to LYNCHAJ at YAHOO.COM and I will send your boards right away! There are plenty of PCBs so even if you weren't on the waiting list there should be plenty to go around. Thanks and have a nice day! Andrew Lynch PS, I have some S-100 4MB SRAM boards, S-100 parallel ASCII keyboard interface boards, and S-100 Serial IO boards left too in case you'd like to get some of those and save on shipping. ------------------------------ Message: 23 Date: Sun, 08 May 2011 09:37:15 -0700 From: "Chuck Guzis" <cclist at sydex.com> Subject: RE: Desoldering a chopper transistor To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID: <4DC6644B.215.F1880 at cclist.sydex.com> Content-Type: text/plain; charset=US-ASCII On 8 May 2011 at 10:57, Rob Jarratt wrote: > damage is strange and I am not entirely convinced it was me because it > is a little distance from the pin, perhaps 5mm away and it is a break > in the track. It looks like I could have let the iron slip across it, > but I don't recall that happening, and the break seems too wide for > the size of bit I was using. Is it possible there might have been a > latent track defect that the heat from the iron revealed? Take a close look at the gap. It's not unusual to see board revisions done this way--just a bit of tape on the master negatives to do a cut in a trace. If the edges of the break look smooth and straight under magnification, you most likely have your answer. Do not attempt to bridge gaps such as this! --Chuck ------------------------------ Message: 24 Date: Sun, 8 May 2011 12:43:59 -0700 (PDT) From: David Griffith <dgriffi at cs.csubak.edu> Subject: pdp11 CPU on S100 board? To: cctalk at classiccmp.org Message-ID: <alpine.DEB.1.10.1105081242480.23678 at sleipnir.cs.csubak.edu> Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII Given that old Soviet knockoffs of pdp11 cpus can be found on ebay, I was wondering if anyone else has thought of making S100 boards containing said processors. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ------------------------------ Message: 25 Date: Sun, 8 May 2011 13:02:24 -0700 (PDT) From: Roger Ivie <rivie at ridgenet.net> Subject: Re: pdp11 CPU on S100 board? To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID: <Pine.NEB.4.63.1105081301490.1826 at stench.no.domain> Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed On Sun, 8 May 2011, David Griffith wrote: I'm pretty certain there used to be one. Osprey, IIRC, built around a J-11. -- roger ivie rivie at ridgenet.net End of cctech Digest, Vol 93, Issue 10 **************************************