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101090 discussions

(E)PROM, PAL, GAL, CPLD, etc. programming

by sethm＠loomcom.com

Hey folks, I'd like to get some advice on getting a general-purpose (E)PROM burner. I've never burned a PROM in my life, but as I get more into digital design and home-brewing logic, I'm finding myself wishing I had access to a burner. I am a helpless newbie on this front, so perhaps someone can show me the light. I'd ideally like to be able to dump and burn PROMs, EPROMs, and PALs of various flavors. Bonus points would be GAL and CPLD programming capability, but I don't know how common it is to find both of those in the same box. Is it? Or is programmable logic typically handled by a totally different device? Availability is important -- I'd prefer to find one I can buy soon rather than waiting for just the right one to show up on eBay. And yes, just to prove that this is more or less on topic: I have been given a box of early 80s EPROMs I would like to try to get dumps of! Thanks much, -Seth

17 years, 10 months

[personal] UK Computer Museum on TV

by roger.holmes＠microspot.co.uk

> From: "Mike Hatch" <mike at brickfieldspark.org> > > TM4's were on the SDS9300, six of them, as I recall they were 10 > track but > something also says 9 track, after all it was 35 years ago !.. Thanks for that. Yes a long time ago. > There were also TM4's fitted to an ICL (I think a 1901) machine up > in London > but I only visited for service once (dirty contacts on the tape arm > switches). More likely a 1301. When the 1301s were being phased out they had to connect a pair of 7 track decks to the 1301s to transfer data to 1900. If they'd had 1900s with TM4s they would surely have chosen that route instead. I presume you mean the contacts with the dash-pot attached, not the switches at the end of arm's travel as these are fairly bullet proof. Now I've said that, they will of course fail next week! I was chatting to a friend who was an ICT field engineer yesterday and he said 'we must clean the vacuum chambers sometime'. I asked him how often they should be cleaned and he said at the start of every morning shift. This made us both grin because they have not been cleaned since about 1977 and they are still not causing any problems, we can read tape last written at that time too, though the writing logic 'runs away' for some reason. > There were also TM2 drives on a LEO3 #26 at Charles House in London > maintained by ICL for running gas bills. I gather quite a number of > the Leo > machines used TM drives. They were popular on 1301s too, though no TM2 equipped 1301s have survived. They had four times the throughput of the TM4 decks as they used 8 data bits per frame plus 8 cyclic redundancy check bits. The tape moved as 150 inches per second too compared with just 75 on the TM4s giving 90k digits per second compared to 22.5k on the TM4. Still 300 bits per inch on each track though, seems very low density by today's standard. Roger Holmes.

17 years, 10 months

powering up older machines - is it safe?

by ajp166＠bellatlantic.net

> >Subject: Re: powering up older machines - is it safe? > From: Steven Hirsch <snhirsch at gmail.com> > Date: Tue, 03 Jun 2008 09:00:15 -0400 (EDT) > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > >On Mon, 2 Jun 2008, Allison wrote: > >> Generally yes in my exerience. The PS is a ASTEC switcher in the drive snippage... >Allison, > >Do you recall anything about the semi-mythical Corvus interface for the >VT180? It's mentioned in the Corvus technical literature, but I've never >talked to anyone that's actually seen it in the wild. I'm curious if it >ever actually existed. > >Steve Nothing mythical. There was a version of the corvus interface that was a board that went under the Z80 and therefor allowed most any Z80 system to accept the corvus hardware. It wasn't however sold as a uniquely Robin thing. FYI the Robin does not have any for of external bus. If you want access to the bus you have to jack up the Z80 and grab it there. I ahve a Vt180, Vt185 (VT125+VT185 board) and maybe 4 VT180 boards rigged as standalone and a dozen more if I need a Z80, 8k of shadow rom, 65K of ram, 4 serial ports and a FDC on one nice board. Allison

17 years, 10 months

PDP-11/40 for sale

by dave＠mynatt.biz

Hi, I'm the program director for a non-profit in Colorado and I am looking for a PDP-11 that we could use to introduce students to the early IT beginnings. I am hoping you may still have a surplus PDP-11 that we could pick up and cart away. You ad on http://www.classiccmp.org/pipermail/cctech/2008-February/091447.html is perfect for me, if it's still available. Dave Mynatt ===== http://sciencecenter.no-ip.org SID ID: S-0258 APRS UI-View KA0SWT LAT: 38'16.278" N LON: -104'40.537" W Alt: 4780ft DM78

17 years, 10 months

MicroVax batteries

by cclist＠sydex.com

> Date: Thu, 5 Jun 2008 17:23:03 -0700 (PDT) > From: Mr Ian Primus > > The batteries in my MicroVaxen need to be replaced. A couple of > questions: > > What's the best way to clean up corrosion damage caused by these > batteries? With Alkaline batteries, I usually use vinegar (since alkalines > leak a base, not acid). What about NI-CD? They still use a strong base (potassium hydroxide), so vinegar is still a good idea. KOH is nasty--keep it off your skin and out of your eyes. Rinse well; follow up with methyl alcohol. Cheers, Chuck

17 years, 10 months

powering up older machines - is it safe?

by eric＠brouhaha.com

Brian wrote: > If that's the smoke he smelled, he wouldn't care about the other > machines. He'd be off looking for munchies... "Now where were > those chips?" Mmmmm... NMOS chips... With just a hint of boron...

17 years, 10 months

C <-> ASM translation problem

by lehmann＠ans-netz.de

Hi, As I promissed here comes my first question ;) While writing several C files for the WEGA/ZEUS kernel out of the disassembled objects (with unresolved symbols marked as external) I came across a piece of code I can't get to reproduce when compiling C. The original object contains: 0006de: 35a2 0004 ldl rr2,rr10(#$0004) 0006e2: 9424 ldl rr4,rr2 0006e4: 0704 7f00 and r4,#$7f00 0006e8: 5d04 8000 0004 ldl $8000+$0x4,rr4 I tried to reproduce it: ipc.ip_addr.l = *(unsigned long)(uap->addr.l)&0x7F00FFFF; Which generates: 0008 35a2 0004 59 ldl rr2,rr10(#4) 000c 0702 7f00 60 and r2,#32512 0010 5d02 8000* 61 ldl _ipc+4,rr2 0014 0004* which looks for me functional the same... I also tried: ipc.ip_addr.l = *(unsigned long *)(uap->addr.l)&0x7F00FFFF; Which generates: 0010 35a2 0004 60 ldl rr2,rr10(#4) 0014 1424 61 ldl rr4, at rr2 0016 0704 7f00 62 and r4,#32512 001a 5d04 8000* 63 ldl _ipc+4,rr4 Which looks "better" but isn't the same as the original because the adress of rr2 gets loaded into rr4 first, not rr2 itself. I'm a bit lost because I tried several different */&-pointer stuff to get this as it is in the original object without success. the elements ip_addr and addr are both of type saddr_t which is declare as follows: typedef union { caddr_t l; struct { unsigned left; unsigned right; } half; } saddr_t; /* segmented address with parts */ rr4 itself gets later overwritten in both codes - my code and the original object - it is not reserved for an internal C-variable. Maybe someone from you can help me here? -- Oliver Lehmann http://www.pofo.de/ http://wishlist.ans-netz.de/

17 years, 10 months

[personal] UK Computer Museum on TV

by roger.holmes＠microspot.co.uk

> From: "Mike Hatch" <mike at brickfieldspark.org> > > Have past experience with Elliott 803b, Digital PDP7 & 11/20, > Scientific > Data Systems SDS9300, ASR/KSR 33 & 35, Ampex TM4 tape drives. May I ask what machine the Ampex TM4 tape drives were connected to? I have them on my ICT 1301s, and I have a slightly different deck marked TM4 Leo but if you know of any other machines which used them it would be interesting. Do you know if they were always ten track read/write heads or were they different configurations? I guess the formats were different across different machines, it seems unlikely anyone else would have chosen to use 4 data bits and 6 CRC bits, and certainly not in multiples of 12 digits with the digits from each half of the word interspersed ending at a word of hex FFFFFFFFFFFF. Roger

17 years, 10 months

Australian Computer Museum

by jules.richardson99＠gmail.com

Does anyone know the fate of the Australian Computer Museum? Looking at their website at http://www.acms.org.au it looks like they were in real trouble a couple of months back. Does anyone know if they found alternative storage space for the collection (and therefore that the website just hasn't been updated)? cheers Jules

17 years, 10 months

Venner Electronics Modules

by thrashbarg＠kaput.homeunix.org

Hi, I've got here some electronic modules made by Venner Electronics LTD, Kingston By-Pass, New Malden, Surrey. One is a Transistor Decade Unit type TS.10/5 and the other just has Type TS 11/HF on it, where 11/HF is scratched into the metal label. Opening one reveals a number of Mullard OC44 Ge transistors. What on earth are they for? I can imagine they're for some sort of digital machine or even a whole computer, but I can't find any information about them or the company. Thanks, Alexis.

17 years, 10 months

Reconstructing Fastback Plus Backups from floppies

by johnwatson97＠optusnet.com.au

Hi Gary, I saw your 12 Mar 2007 post about reconstructing Fastback files. I have EXACTLY the same problem ! Did you get a solution ? Regards, John Watson.

17 years, 10 months

is this a terminal multiplexer?

by legalize＠xmission.com

See ebay item # 120269073061 We've talked about terminal multiplexers here before, as opposed to terminal servers. They sound like interesting devices to me and I was wondering if this item on ebay is one of those muxes or some kind of telecom equipment instead (its listed under telecom, but ebay items are often listed under the wrong category). -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

17 years, 10 months

classic computer/game machine color video generation

by chd_1＠nktelco.net

How is the color video for display on a TV generated? I have a reasonable understanding of how the composite video signal works, although probably not all the details. Each horizontal scan line consists of a lower frequency signal that represents the brightness with higher voltage being darker. Added to this is a higher frequency signal that represents color and the color is determined not by amplitude, but by phase shift relative to a reference generated during the horizontal retrace time. So, if this is how the video signal works, then to generate 16 colors, we could use one bit for a brightness level and 3 bits to select a color. I can see a D F/F to hold the brightness level during a pixel time.For color, I see an 8 bit shift register with the color signal being shifted though and an 8 to 1 multiplexer to select the phase based on the 3 color bits during each pixel time. Now add some resistors to set the right levels and maybe some capacitors to take off the sharp edges and you have a video signal. I know this is ignoring the sync signals. I am really interested in how you get color. OK, so how close am I? -chuck

17 years, 10 months

N8VEM homebrew SBC PCBs

by lynchaj＠yahoo.com

Hi All, I did finally finish my homebrew SBC PCBs and made an order for several. The manufacturer says they should arrive about 5 Jun 2008 or so. If anyone is interested in building their own, please let me know. The details about the SBC are at: http://groups.google.com/group/n8vem/web/n8vem-single-board-computer-home-pa ge http://groups.google.com/group/n8vem Thanks! Andrew Lynch

17 years, 10 months

Trying again, wanted: volker-craig terminals

by dgahling＠hotmail.com

I'm trying this again, since I still haven't gotten one, I'm looking for a volker-craig terminal, preferably an 4404 (not a 3000-series). I used these at western and would love to have one. If anyone has one they want to get rid of, sell, trade, etc, please let me know. Thanks, Dan. _________________________________________________________________ If you like crossword puzzles, then you'll love Flexicon, a game which combines four overlapping crossword puzzles into one! http://g.msn.ca/ca55/208

17 years, 10 months

Searching (again) for some Arpanet-related Documents

by spedraja＠gmail.com

Hello. I should agree if someone could provide me one copy of these documents related with the Arpanet: * BBN Report n.2184, "TIP Hardware Manual" * BBN Report n.2161, "A Study of the ARPA Network Design and performance" * BBN Technical Information Report (TIR) n.89, "The Interface Message Processor Program" * BBN Technical Information Report (TIR) n.90, "The Network Control Center Program" * BBN Technical Information Report (TIR) n.91, "The Terminal Interface Message Processor Program" * BBN Technical Information Report (TIR) n.93, "The Remote Job Entry Mini-host" * BBN Reports n.2999, 2930, 3000, 3001, 2931, 3002, 3004, 3056 and 3126, all of them related with the Pluribus IMP. * NIC 6740, "The Network Resource Notebook" * NIC 7104, "ARPA Current Network Protocols" * NIC internal/informal notes named "TIP Users Group Notes" Thanks and Greetings Sergio

17 years, 10 months

Documation tags

by wdonzelli＠gmail.com

I have a couple of metal tags for a Documation M200 card reader - one the front green tag with M200 and the logo, and the other the back (bottom?) black tag with the serial number and stuff. Both in pretty nice shape. All this for a buck! Postage included! Don't be a dick and reply off list, please... -- Will

17 years, 10 months

is this a terminal multiplexer?

by aek＠bitsavers.org

It is a T1 channel bank. One end of a multiplexed point to point connection through a (roughly) 1mbit pipe. Most of the cards are for POTS lines.

17 years, 10 months

PDP 11/93 + RSX 11M

by support＠simation.com

Hello Henrique, i have same problem as you, reading BRUSYS floppy from RX33, do you get any help according to your question?, i would appreciate any help you can give me thank you Rolando Cornejo Dear Sir, I?m in trouble with the system as the boot stops at : RSX-11M - Plus V4.3 BL66 2044.KW System "Pt/Ps" > RED DU:=SY: when loading from RD53 (RZ 28M-E) and stops at: RSX-11M/RSX-11M Plus Standalone Copy System V03 when loading from RX33 (Brusys floppy) Do you have an idea why the boot does not go on? Thanks in advance, Henrique Gomes.

17 years, 10 months

Australian Computer Museum

by gerhard.kreuzer＠liftoff.at

Hi, I just recognize this situation before 1th of April, and I send eMails, that I could take care of one or two dec systems (pdp8) but I never get an answer back. Hope their systems arnt scraped!!!!!!! Yours Gerhard

17 years, 10 months

UK Computer Museum on TV

by aliensrcooluk＠yahoo.co.uk

I for one would like to see it (hope you remembered to record it!). I would see it myself, but our aerial is actually pointed to Central and not Sandy Heath (Anglia TV) after my parents got some guy out to allow my & my bro to have a 2nd aerial line fitted into our bedroom years ago. We didn't realise what he had done until he had left and he never returned any of my dads phone calls. I guess you could say he was a rogue trader of sorts. I couldn't be more local to Cambridge... ok, perhaps I could if I lived *in* Cambridge and not nearby (Cottenham). I'd certainly be interested in being involved with the museum, once I get up and running with my car. Regards, Andrew B aliensrcooluk at yahoo.co.uk

17 years, 10 months

MicroVax 3900 current draw and heat output?

by ian_primus＠yahoo.com

I'm in the process of thoroughly cleaning my MicroVax 3900 in preparation for installing it in my upstairs computer room. This will be the only "big"* machine up there, all the rest of the iron lives in my semi-finished basement computer room. (concrete floors, plenty of headroom, easy power installation...). The problem is, that my upstairs computer room has always had a bit of a problem with heat and power. I'm installing a second 15amp circuit, but heat dissapation will be limited to the central air conditioning and ceiling fan. So, what I'm wondering is... how much power will a MicroVax 3900, with two RA90's, draw? And similarly, how much heat will it put out? Thanks! -Ian * Note how I put "big" in quotes. I know that a MicroVax 3900 is not a big machine, compared to, say, most of the other Vaxen and stuff I own. But, it's bigger than an SGI Octane, it's bigger than a Macintosh, and it's bigger than the PC's and all the other boxen that live upstairs. So, comparatively, it's "big". Ironically, however, I think it's smaller than my printer.

17 years, 10 months

Prepare to chuckle...

by tshoppa＠wmata.com

At 6:02 PM -0700 3/9/08, Sellam Ismail wrote: >http://www.vintage.org/blog.php?action=read&pid=22 That's not bad at all compared to some of the stuff I've bought over Ebay. I've been pretty disappointed at some of the 50 or 70 pound lab instruments that look to be in perfect pristine condition before they're shipped to me - but arrived in way way too little packaging and with all the corners bashed in and knobs broken off by the time they get to me. Usually I'm so sad about the whole destruction of what was just a few days before a very nice example of 50-year-old technology that I can't even bring myself to leave negative feedback. What's the point, the seller won't learn, and history's been lost in any event. I'm even sad that I participated in the destruction (although I make it very very clear to the seller what I think he ought to do in shipping, usually the seller just takes it to the "UPS Store" and let them put it in a lightweight carboard box with some peanuts.) I'm left not chuckling but pretty depressed. Tim.

17 years, 10 months

powering up older machines - is it safe?

by ajp166＠bellatlantic.net

> >Subject: Re: powering up older machines - is it safe? > From: ard at p850ug1.demon.co.uk (Tony Duell) > Date: Tue, 03 Jun 2008 04:39:09 +0100 (BST) > To: cctalk at classiccmp.org > >> > The main worry is not a capacitor Failing. The main worry IMHO is that if >> > there's a fault in the power supply regulation circuitry then that could >> > make the +5V line jump to a high enough voltage to wipe out just about >> > every chip in the machine. Expansive and difficult to put right. However the swithers used are less likely to overvolt than fry the high voltage side (chopper fails!). In the case of the Robin that is there the risk is (other than the video board cap). Allison >> >> I don't disagree with the concern, but I'd be interested in hearing >> estimates on the probability of this taking place. Has anyone had it >> happen to them? > >Yes, sort-of.... > >I've never had it happen in a classic computer, but years ago I was >making a homebrew SC/MP machine. I'd obtained a surplus PSU which I'd >tested and worked fine, and then stuck on the shelf. I was foolish enough >to get it out a couple of mnths later and attempt to use it to power my >homebrew board. Alas something had failed in the PSU (I forget what, it >might just have been a dry joint...) the +5V output was at about 9V. This >wiped out the SC/MP, a couple of 2114s, and at least one TTL chip >(amazingly much of the TTL eurvived). > >I was a schoolboy at the time, and it took a lot of weeks of saving >pocket money to replace that SC/MP. I guess that's why I'm now (over-) >cautious... > >-tony

17 years, 10 months

Semi-OT? HP 1630G Logic Analyser (grabbers, invasm packs & disk drives)

by jplist2007＠kiwigeek.com

Hey folks; So I'm busy reading the manual to my brand-new-offa-eBay 1630G and, page by page, I'm more and more impressed. I've never owned one before and it just seems like pure magic. I've got it hooked up to a huffy Vector Graphic in my basement (which diagnosed a bad Z80 in a matter of seconds on my test try!) and boy is it useful. First business - does anyone have swaths of the double-grip HP probe grabbers they might be willing to part with for a reasonable sum? Just askin' :) I'm reading the section on the 'inverse assembler', which really is remarkable (like I said, I'm new to this) to have it disassemble various CPU instruction sets. What I do not have, though, is either the appropriate disk drive set (HP 9121S or 9121D, according to the manual) nor any of the invasm packs. I don't suppose there's anyone out there who may be willing to also part with either of the above, again, for reasonable recompense? With the Vector I'm interested in Z80 invasms - but, frankly, the options seem endless given the smattering of 8-bit processors I have covering my shelves in need of attention. There's a 9121D on eBay (6 days out) for $60 w/shipping, which is... do-able but seems a shade hefty. Maybe they're getting harder to find these days, I don't know. As for the invasm packs, for all I know they're complete unobtanium - but I figured I'd go to the repository for such knowledge and see what people thought. Many, many thanks to all. - JP

17 years, 10 months

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