test-drb

test-drb@ccmp.vtda.org

101090 discussions

by dm561＠torfree.net

-------------Original Message(s): Date: Sun, 11 Nov 2007 21:25:13 -0800 From: "Chuck Guzis" <cclist at sydex.com> Subject: On 11 Nov 2007 at 20:49, Jim Leonard wrote: > The digitized examples (Kennedy, etc.) weren't that much better > either... I wonder, with modern computers making the FFT analysis, could > the computalker produce intelligible output? I can only assume that the > original analysis was limited by the speed of its day. I don't know--the CT was a strange board. I do recall at one point having a Votrax Type'n'Talk RS-232 text-to-speech box installed on a terminal. To this day, I still say "ok" (rhymes with "sock")... ;) Cheers, Chuck -----------------Reply; Same here; one of the Cromemcos had a Votrax on a dedicated port that announced the user's name and port no. when he/she logged in, and for many years I've had a PC set up with an RS-232 speech card that announces the caller's name and number when my phone rings, as well as logging the call. mike

18 years, 5 months

S100 Floppy Controller Question

by dm561＠torfree.net

---------------Original Message: Date: Sun, 11 Nov 2007 17:51:09 -0500 From: Allison <ajp166 at bellatlantic.net> Subject: Re: S100 Floppy Controller Question To: cctech at classiccmp.org Message-ID: <0JRD004G7656LL73 at vms044.mailsrvcs.net> Content-Type: text/plain; charset=iso-8859-1 > >Subject: Re: S100 Floppy Controller Question > From: M H Stein <dm561 at torfree.net> > Date: Sun, 11 Nov 2007 17:33:20 -0500 > To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org> <snip> >I think Tim's point was that if your controller's smart enough to deal with a >relatively modern 8" drive like a TM848 it could probably deal equally >well with a 5.25" HD drive and you could transparently restore an 8" image >(if you have one) to the 5.25" disk. The controller (and CP/M) would not >even know that it's a 5.25 instead of an 8"; my Cromemcos certainly don't, >although a different FDC might well require some mods to the BIOS. Different FDC WILL require a different bios. Same for SERIAL IO. Allison -----------Reply: I think you might have misunderstood, Allison; sounds like you thought I was talking about replacing an FDC with one other than what the BIOS is configured for; obviously that will require mods to the BIOS. What I was responding to was a previous post that suggested replacing an 8" drive with a 5 1/4" HD drive might require mods to the BIOS, and I just wanted to mention that this is not the case with a Cromemco 16/64FDC, to which a TM848 and a JU475 appear identical as long as the jumpers on the 5 1/4 drive are set correctly and it supplies /READY, and that this may also apply to some other controllers. Also, if the controller has both 8" and 5 1/4 connectors and they are effectively in parallel as they are on the Cromemco, you may not even need a 50<>34 pin adapter cable. Nevertheless, controllers meant for some of the older, non-'standard' 8" drives probably will require changes to the BIOS, and likely also hardware mods. mike

18 years, 5 months

MIT provides MULTICS source and documentation

by ggs＠shiresoft.com

Hi, I don't know if anyone else noticed but MIT has released the source (and documentation) to MULTICS. The link is: http://web.mit.edu/multics-history/ I haven't gone through it (yet) but thought I should bring this great news to everyone's attention. -- TTFN - Guy

18 years, 5 months

Docs for Chipcom ONline System Concentrator and Online NCS

by steve＠radiorobots.com

Hi, Trying to re-create, at least on paper, a system I used in the early '90s. Looking for docs for Chipcom ONline concentrator and NCS. Thanks, Steve

18 years, 5 months

More pollution- Onyx (1) in California, also free

by compoobah＠valleyimplants.com

http://forums.nekochan.net/viewtopic.php?f=4&t=16005 Don't know if he'll ship, but move fast if you're interested.

18 years, 5 months

beckmen industrial circuitmate 9020 osilloscope operaters manual

by thenicnics＠tiscali.co.uk

Hi Dan Please would you contact me if you still have a Beckman industrial circuitmate 9020 oscilloscope operators manual MANY THANKS Gary Nicholson

18 years, 5 months

DEC sun3 gear available in Ottawa

by dave06a＠dunfield.com

Hi Guys, A friend of mine is cleaning his basement, and offers up some equipment, located near Ottawa, Ontario Canada. Please see: http://www.ba23.org/blog/2007/11/12/index.html#free > Free gear available for pick-up in Ottawa. Will consider shipping > if you are willing to pay packaging and shipping costs. > > I need to get this stuff out of my basement. > > - Sun 3/50 and Sun 3/160 > - MicroVAX-II in a BA123 enclosure > - DEC RL02 drives > - AlphaServer 2100 > - DECstation 3100 > - SPARCstation IPC > - VT100 Tempest > > > There will be more gear available. I will update this webpage as > I sort out the gear -- http://www.ba23.org/page0290.html -- dave06a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.classiccmp.org/dunfield/index.html

18 years, 5 months

MIT provides MULTICS source and documentation

by blstuart＠bellsouth.net

From: Sridhar Ayengar <ploopster at gmail.com> > > Brian L. Stuart wrote: > > segmentation structure. Unfortunately, it's only got 32-bit > > addresses. Even in the 60s, the Multics machines had 36. > > Pardon my ignorance, but were there any places where the top four bits > were actually used? I mean, I don't believe there was a machine back > then capable of running MULTICS and also having more than 8Gb primary > storage. Wouldn't it be possible to fake it by just chopping off the > four most-significant bits and using the remaining 32? It's the virtual addresses you really care about. So the limit of physical memory is really a diffent issue. The address was used in 2 18-bit parts. The upper part was the segment number and the lower the offset into the segment. That meant segments could be no more the 256K and you could have no more than 256K of them. Because there was a one-to-one correspondence between files and segments, that would have limited files to 256K. They did some "stuff" to get around that, but I don't think it's what you'd do if you were starting from scratch, or maybe even doing a fresh port. If you divided the 32-bit address into a 14-bit segment number and 18-bit offset, then you could keep the same segment size and the only limit would be that a process could use no more than 16K segments. All in all, it'd be a whole lot more fun to use a 64-bit machine and divide it into 32 and 32. BLS

18 years, 5 months

MIT provides MULTICS source and documentation

by blstuart＠bellsouth.net

> > >> But what machines could run the that today? > > > > > > Anything you port it to. The segmentation architecture would be hard to fake. And the idea of segments is so deeply ingrained, I doubt you'd want to try. However, the x86 does seem to have the necessary segmentation structure. Unfortunately, it's only got 32-bit addresses. Even in the 60s, the Multics machines had 36. > > That's an interesting question. I can't think of that many machines > > with a hardware ring architecture, and it's not something that can be > > easily faked with more traditional architectures. It would be a fairly > > invasive "port". > > It pains me to say it, but you could just throw CPU horsepower and > memory at the problem. Yes and no. In principle, the only thing you'd have to ensure is that you gave control to the supervisor on a ring crossing. So you could make all pages not in the current ring inaccessible. On a page fault, apply the ring brackets in software and change the page tables as a result. At the very least, you'd take a performance hit. Having said that, somewhere in the back of my head, I want to say that the x86 has at least part of the mechanism already. So a port to it would be less painful than to a lot of others, except of course, for the smaller address space. Of course, I could be totally off. I'm certainly no Multics expert, and my memory of the details of the x86 segmentation are rusty at best. BLS

18 years, 5 months

MIT provides MULTICS source and documentation

by blstuart＠bellsouth.net

From: Chris Kennedy <chris at mainecoon.com> > > Brian L. Stuart wrote: > > >>From multicians.org: > > Although there were 64 rings (an illusion created by software) on > > GE 645 Multics, there are 8 rings, supported in hardware, on the > > Honeywell 6180 in its various models. > > As opposed to what? Four on the X86? > > The original question remains, how many rings does Multics need? Just > because eight were provided by hardware doesn't mean they were all used. For the most part, they used 0-4. I don't think you'd actually need 5-7. BLS

18 years, 5 months

MIT provides MULTICS source and documentation

by blstuart＠bellsouth.net

From: Chris Kennedy <chris at mainecoon.com> > > Sean Conner wrote: > > > I can think of several thousand that have been made over the past decade, > > all made with the Intel x86 architecture. It even has the segments that > > Multics used. Seems like a perfect match to me. > > Hence my question regarding the number of rings used by Multics. Just > because there's multiple contexts doesn't mean that there's _enough_ of > them. >From multicians.org: Although there were 64 rings (an illusion created by software) on GE 645 Multics, there are 8 rings, supported in hardware, on the Honeywell 6180 in its various models. BLS

18 years, 5 months

Found a NCR system 3400 BoatAnchor

by laura＠gbsncr.com

I am looking for information on how to find some part numbers to my NCR 3400 machine. I need one master slave (3) cables that go to the NCR3400 and the controller box (possible pn: 5300008319) for the tape drive (initialization tape 5 ?? tape). Please let me know if you can help. Laura Ellingson Sales & Marketing Manager Guarantee Business Systems, Inc. 800-650-1457, X429 651-286-8429-Direct 651-688-6160-Fax <mailto:laura at gbsncr.com> laura at gbsncr.com <http://www.gbsncr.com/> www.gbsncr.com GBS is a Woman Owned Small Business & Service Disabled Veteran Owned. We are a POS, Storage, networking hardware solution provider - in the IT industry since 1986.

18 years, 5 months

Architecture vs Implementation

by aek＠bitsavers.org

> If a processor has 16 bit registers, 16 bit math and address > calculation, and a 16 bit address bus, but it's ALU is only 8 bit and > its internal data bus is 8 bits, it's an 8 bit processor. Right? wrong -- The 360/30 /40 and /50 are all considered members of the same 32 bit architecture, and have 8, 16 and 32 bit data paths, respectively. An 80386/SX is not considered a 16 bit processor because it has a 16 bit data bus. People are confusing architecture with implementation. Is a PDP-8/S a one bit processor because it implements arithmetic serially?

18 years, 5 months

Older Apple Macintosh books, manuals, Apple 2e card.

by trag＠io.com

> Date: Mon, 12 Nov 2007 09:30:42 -0700 > From: Richard <legalize at xmission.com> > Subject: Re: Older Apple Macintosh books, manuals, Apple 2e card. > In article <38603.209.163.133.242.1194883321.squirrel at webmail.io.com>, > "Jeff Walther" <trag at io.com> writes: > >> The IIe card has an actual IIe-in-a-chip on board. It plugs into an LC >> slot. The "LC-slot" originated on the Mac LC, but was instantiated on >> many Mac models after that. > > Is the "LC-slot" referring to the form factor or the bus interface? Primarily the bus interface. There may have been other Apple connectors which used the same physical connector but were wired differently. I am not aware of any, but Apple did this with other connectors. For example, the PDS connector in the IIci, IIsi and SE/30 are the same physically, but the IIci's is wired quite a bit differently, and even the IIsi and SE/30 have minor differences, though the latter doesn't stop cards from being cross-compatible. > Is this a NuBus slot? No. Apple was very fond of the Euro Mini-DIN connector in various pin numbers, but it is not the same as a NuBus slot. >> A IIe expansion card enthusiast has a very informative website up on the >> topic. > Is this the one you're thinking about? > > <http://www.vintagemacworld.com/> > Apple IIe Card for the Macintosh LC Frequently Asked Questions That's it. Anywhere that FAQ and I differ, I'm probably wrong. Same for me and Cameron's post which I saw after I wrote mine. Jeff Walther

18 years, 5 months

At risk of polluting the list with micros- IRIS Indigo adv. for free.

by compoobah＠valleyimplants.com

See http://forums.nekochan.net/viewtopic.php?f=4&t=16095 Looks like a R3000 model with XS-24Z, XZ, or Elan graphics Not mine, in Oregon.

18 years, 5 months

CRC question

by dkelvey＠hotmail.com

> From: cclist at sydex.com > > On 11 Nov 2007 at 10:37, dwight elvey wrote: > >> To my knowledge, I don't know if any of the assemblers had >> a CRC calculator built in. The final check number was most >> likely calculated after the assembly and just added to the code. >> If in the listing, this may have been a second pass through >> the assembler. > > MAC certainly didn't have one. I assume that the last 2 bytes of the > ROM were the zero-CRC-makers. The "quick and dirty way" to get a > zero sum is to compuate the CRC for the first n-2 bytes of the size n > ROM, then iterate through the 65536 possible 16-bit combinations of > the "corrector" stopping when a zero CRC is hit. It shouldn't take > long, particularly if you're using an emulator on a modern PC. > > You could also work out the reverse polynomial, but that sounds like > too much work for what probably will amount to a one-off deal. > > Cheers, > Chuck Hi Chuck As I recall, you just play the CRC forward with 0's in the two bytes. The value in the CRC is then just put into the place of the two bytes. It the will cancel to zero. I'd have to check that but that is what I recall. I recall it wasn't all that complicated. Remember, CRC circuits in controller chip do this for floppy disk without complicated circuits. It has been some time since I played with CRC's. I once had to write test to check CRC chips that used the Chinese Remainder Theorem to make data correction. I had to make sure that it corrected correctly by checking each part of the error correction. That was many years ago. Dwight _________________________________________________________________ Boo!?Scare away worms, viruses and so much more! Try Windows Live OneCare! http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=wl_hotmail…

18 years, 5 months

cctalk Digest, Vol 51, Issue 37

by compoobah＠valleyimplants.com

On Nov 11, 2007, at 11:21 PM, cctalk-request at classiccmp.org wrote: > What I meant to say is that the investor who get in turn the hobby > into a > business. Get in buy low, trade items around between other investors to > drive up the costs, sell out and find another pump and dump hobby. It > leaves > people thinking their stuff is worth money when the people with the > money > are long gone. Granted people will dig up those rarities and trade them > around so they do not get trashed, so there is a plus side to it > (things get > preserved). > There's another factor here - people like Will and Paul and Sellam (probably) don't cater to deep-pocket collectors as their primary customers. They cater to businesses who still use the machines in day-to-day operations and are happy to pay what's needed for a part so they can get it next-business-day. The other market is lawyers looking for prior art evidence. In both cases the bankroll is substantially bigger than almost any collector, so collectors get locked out through no nefarious intent of the dealers. Remember there's quite a lot of overhead in locating, buying, storing, organizing, and dealing that one part that one person will need every 5 years (or longer for the lawyers - maybe only once in 50 years, but they're willing to pay). Off of this there is a certain amount of hype-induced market pumping (lookit how much that old thing sold for! I'm gonna dump my beanie babies and invest in cawm-pew-tuhs (yes, more sophisticated certainly, but it's a fun image), but that is vapor wealth because those people don't have the support to deal to businesses and probably have no interest in doing professional lawyer supply so the investment is probably as good as shares in "Gobi Rainforest Woods Limited" > The only thing stopping me from fighting over the big boys for my > collectables is that nothing I collect would interest the big deep > pocket > collectors in the first place. Everything I like was made in the > thousands > or millions, outbid me today and I just wait for the next one, or find > it at > a garage sale for $1. I guess if I was older and used computers pre > 1980, I > might want some of the rarer systems that command money, but they just > don't > mean anything to me so I don't bother. I certainly wouldn't mind trying out a HP2100 or 3000, or an IBM mini/mainframe, but definitely same boat here - wussy micros only (unless you count the TAAC board which might be a mini). I'm a bit gunshy too, after the trouble it took to outfit my $25 VAX 4200 I'm hesitant to get into something that I don't know especially if it's pricy.

18 years, 5 months

Older Apple Macintosh books, manuals, Apple 2e card.

by trag＠io.com

> Date: Sun, 11 Nov 2007 21:41:34 -0800 > From: Scott Quinn <compoobah at valleyimplants.com> > Subject: Re: Older Apple Macintosh books, manuals, Apple 2e card. > To: cctalk at classiccmp.org > The Apple // cards (I think it was a //e) fit in the LC PDS (LC, LCII, > LCIII, not sure about the '040 LCs) and are a genuine Apple product > that was pretty much 100%. While most of the (usually schools) using > them would move their Apple // software to either 3.5" or hard disk, I > think that Apple made a Macintosh-compatible 5.25" floppy that would > read Apple // disks (I know they made an IBM 5.25"-compatible floppy > drive for Macintosh back in the late 1980s), but not many were sold. The IIe card has an actual IIe-in-a-chip on board. It plugs into an LC slot. The "LC-slot" originated on the Mac LC, but was instantiated on many Mac models after that. The rule to distinguish 68040 based machines with an LC slot is that 68040 machines which can boot into 24 bit addressing mode will support the IIe card and 68040 machines which cannot boot into 24 bit addressing mode (IOW, 32 bit only) cannot support the IIe card, even though it will plug into the LC slot. IIRC, the Quadra 605/LC605/P605 supports the IIe card and the Quadra 630 family (Q630, 631, 635, 636, 640, and LC and Performas with same numbers) does not. Most machines with an LC style expansion slot have no other expansion slots, so installation of a IIe card precludes adding an ethernet card and other expansions. The Q63x family has a comm slot and an LC slot, so one could have an ethernet card in the comm slot and a IIe board in the LC slot, if they supported the IIe, which they don't. Grrrrr. The IIe card has a connector on the back plane for a custom cable. The custom cable splits into a joystick connector and a floppy drive connector. So one can connect a IIe joystick to the IIe card and one can also connect a 5.25" floppy drive to the connector on the special cable. IIRC, there is a model(s) of 5.25" drive which will work and another (others?) which will not, but I don't rememember which is which. Still, one does not need a special 5.25" drive. The connector is for one of the external 5.25" drives which was supported on the original Mac IIe. The IIe card uses the host machine's keyboard, mouse, display, hard drive and built-in 3.5" floppy drive. A IIe expansion card enthusiast has a very informative website up on the topic. And I will be useless here and fail to have the URL. But the resource exists and covers the information above to a useful level of detail. Jeff Walther

18 years, 5 months

cctalk Digest, Vol 51, Issue 37

by compoobah＠valleyimplants.com

On Nov 11, 2007, at 11:21 PM, cctalk-request at classiccmp.org wrote: > I would love to be proven wrong on this, since it would potentially > make > my II disk archiving a lot easier, but I have never heard of such a > device > for the Mac. > > In the case of the IIe card, this was accomplished by connecting a > regular > Apple II 5.25" drive to the *card*, not the computer. AFAIK same for the DOS compatible drive (though a different card, not the //e). I think somebody (must not have been Apple) did make some sort of drive that did the necessary interface juggling to do 5.25" //-series on the Mac. I was a bit too young to remember specifics, though. Perhaps AE. Pretty sure I've seen reference to it somewhere.

18 years, 5 months

Old Sun diags questions (4/300 and 3/200)

by compoobah＠valleyimplants.com

> Dave McGuire writes: > On Nov 10, 2007, at 1:19 PM, Scott Quinn wrote: > > Couple of questions on old Sun machines (well, parts). > > > > On a Sun 4300 CPU board, I'm getting the > > "EEPROM Write-Write-Read-Read test > > error PA=0xF2000000 VA=0X00FF8000 Exp=0x0000005a Obs=0x00000000 > > (looping)" > > error. Looking on the Web and Usenet seems to show that this has > > happened a couple of times, with some reference to possibly being > > the NVRAM (although the most comprehensive posing set was in > > German :(). This seems a bit odd, though - on my other Suns it > > calls the NVRAM the NVRAM, so I'm wondering if this is something > else. > > It's just a terminological difference. Most of those machines (if > I recall correctly) used 2816 NVRAM chips, which are also correctly > referred to as EEPROMs. Oh, so the Mostek unit isn't what this is talking about. Hmm- have to go over the board again. I saw the Mostek and assumed that it was the same as the 4c/m/u NVRAM setup .

18 years, 5 months

Video clips (was Re: modern serial terminal)

by jeffj＠panix.com

replying to ard at p850ug1.demon.co.uk (Tony Duell) Subject: Re: Video clips (was Re: modern serial terminal) Message-ID: <m1IrKbM-000J3RC at p850ug1> > I am not a 'normal' computer collector, if such a thing even exists. > For one thing I am primarily interested in the hardware design > (if I can get a machine running properly so that it boots the normal OS, > or runs the ROM software, or..., then I tend to lose interest in it). > I am interested in the electronics/engineering aspects, > the fact that the devices happen to be programmable computers is secondary to this. I think I'm in that camp too. I adored pulling apart old electronics to see the immense worksmanchip and craftsmanship required just for the assembly. Old military stuff was designed for reliability, maintenance, repairability, upgrade/replacement, etc. Even just verifying in-spec operation ment test points, built-in meters, test lamps, status indicators, etc. Things that are TOALLY MISSING from today's equipment. Will I ever build anything that magnificent by myself? Unlikely, but I can still aim high. [a quick rant: I've been having problems with my cable internet. I knew it was the modem by watching the status leds as it kept rebooting. How's anyone to diagnose things with only a power LED? Yea, it's sure great to buy 500+ gig hard drives for $100 but without a REAL activity LED, how am I to assure what drive is active? Some drives used to even blink diagnostics on their LED. New PCs are sure fast but without activity LEDs, how is one to isolate faults? That's a far cry from the mainframes with diagnostic LEDs on each card or part for fault isolation Yea, remote diagnostics and SMART give more details but after all that, someone still has to touch the hardware!] > This has several implications. The first, which I think is on-topic, > is that I am equally interested in peripherals as CPUs. > I want to run my PDP11 with RK05s and RK07s and RL02s, and... > Not an IDE drive pretending to be the above. > The design of the servo system in an RK07 > is every bit as interesting to me as the processor. I both agree and disagree. Yes, it's amazing seeing things in motion (particulalry linear motors) and motion control systems where you can SEE the feedback sensors and signals (not just a black-blob of a DSP doing all the work). BUT - when those drives were in common use, there was a support infrastructure. You could buy new disks and the cleaning kits and hire people to clean and check the disks and drives for "preventive maintenance". The drudgery of doing all that maintenance myself made me give up many such projects of running old equipment :-( -- Jeff Jonas

18 years, 5 months

VCFX Photos

by wayne.smith＠charter.net

I have posted some VCFX photos at: http://picasaweb.google.com/Joy.Wayne/VintageComputerFestivalX Labels to follow.

18 years, 5 months

Tarbell is making me insane

by ajp166＠bellatlantic.net

> >Subject: Re: Tarbell is making me insane > From: Grant Stockly <grant at stockly.com> > Date: Sun, 11 Nov 2007 13:21:32 -0900 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > >Tarbell Update > >> >> > Also sounds like oneshot problems. Check cpu timing. Even small timing >> >> > errors tend to magnify bus noise issues and incompability problems. >> >>(Snip) >> >> > Also HEAT. That thing despite a very heafty noisy fan and cover mods >> >> > didn't like heat. FYI: the timing of the oneshots drifts with heating! > >I can't speak for the exact combination of the Tarbell, but the >system has been running all day long with: >-16k static card >-8k static card >-4k static card Ok you have 28k ram. Is the image sized and booting in that? If the image is sized for say 32 or 48K it will crash, likely as a bounce back to rom monitor. >-2SIO Is the boot image set up for MITS 2SIO and does it set it up? >-1k ROM >-8k Byte saver I assume thse are in high memory and not below the address the image will try to boot to. CP/M wants from 0000h to system size as configured. When working on FDCs I load the system with a single known good RAM16, Ram17 or similar 64k static card that can kill the last 4 or 8k. I use a CPU with resident monitor and local ram (compupro CPU Z) and an CPro Interfacer for IO. At that point I know I have a known IO, known CPU and a monitor at F000h with POJ to F000h and ram at F800h. Any time there is doubt about these they get a quick retest in a known backplane (NS*Horizon). This means the system will be 4 boards max with the 4th being the FDC in question. I keep a CCS terminator card handy as it seemed to work the best of all of them. Things I've found in old backplanes. Staples under the S100 connectors. Metal under the backplane shorting to chassis. Terminators with burned off tracks. Metal bits in the connectors Bits of nonconductor in the connectors. Green cruft in the connectors (corrosion) Black card edge connectors (gold over copper without nickle flash, a bad thing) Power supplies with excessive ripple. (tired caps) Power traces fried on the backplane (altair 4slots) Signal traces missing... from a former short? That doesn't even touch on cards that just didn't play well in some machines or with certain other cards. Heres an example of a machine. I have two explorer 8085s. One I built back when and another aquired. They are identical as best as I can see or test. Mine runs perfect, always did with any card I've tried. the second is flaky, won't run any S100 card without a bus terminator and even then it's fussy. I've gone as far as to completely swap every chip (they are fully socketed) between the one that is cranky and my old one is still happy and the newer one not. I've even swapped PSs ( uses s100 style unregulated) and no dice. All on board (there are a few) regulators replaced on the bad one. No help. After a LONG time of testing and all the problem was a high resistance trace on the faulty board. I can see the signal at the source IC solder side but between there and it's terminus it's a 1000ohm resistor! One of the S100 status signals was not quite there and floating. I bridged the trace with blue wire between the two solder pads and it's solid now. I cannot even with a 10x scope see where the apparent crack is. That's chasing a phantom. But I do find the oddest of the odd. >-Tarbell FD > >It has been running solid a 4K ROM monitor from Dave >Dunfield. Floppy interface still doesn't work on either card, and >these cards were tested by someone else on an IMSAI with an Altair CPU card. If it's the monitor I think, it doesnt stress ram just sitting there. You need a memory exerciser running at a minimum to be sure. >>Some Z80 cards complicate the issue. They have different timing and at 4mhz >>some ram MAY NOT be fast enough. Either slow the z80 to 2mhz or more wait >>states from ram. > >The card I have has a switch for 2MHz. The tarbell with the reduced >clock speed will not work at anything higher like you suggested. I >have confirmed (from the person who shipped me the tarbell cards) >that the tarbell card with a reduced clock speed works normally with >a Z80 at 2MHz. Doesnt assure the FDC is set right for the drive and media. Also doesnt assure the media is SD or even bootable. Further is the media is not using a 2sio as the IO the system could boot and crash or appear to. > >I attached a logic analyzer to the drive and watched all of the >signals. Every thing looks normal to me. I hooked it to a 5.25" >drive and then to a 3.5" drive. The drives are sending everything >that they should. Then the FDC is potentialy not decoding the data. > >>Shows how rough the bus timing and noise can be. Is that a one piece >>backplane of the two sided variety or the one of the earlier Altair >>4 slot chains or single sided backplane? The reason is the earlier > >2x4 slot motherboards, but all of the wires are the same length >(there was a tip on that to reduce noise) ICKPOO. Those were the worst for ringing and bus power sag. Poke a scope at it, it's nasty. >I'm going to let the thing heat soak and then check the bus with an >oscilloscope and the CPU clock. if the oneshots are good ones once set they should say put. Then again there was lore and fact about what was and wasn't good. >You know, I'm worried that the reliability issues aren't related to >the Altair, but to a heavily modified tarbell card trying to write a >Tandon SSSD 5.25" onto a 3.5" disk??? Likely if the data rates are not set right for the FDC and it's data seperator (usually also oneshots) is not set right it will fail. Could even be a simple bad IDC crimp on the cable. > >Would any of you like to see the data coming out of the disk >drive? I can upload the logic analyzer data to my web site... Not I. If I did at the very least I'd also need to see the schematic and jumper info for the tarbel. Other wise it's just a pretty picture. >I will never be happy until I find the problem. I'd like to think >that with all of the information we have that I can make the Altair >as reliable as any other S-100 system. I have collected a lot of >errata and have applied it all to my system... That's why I won't >give up with this setup. : ) Most of the erata is lore not hard tried fixes. Most fall in the "it worked for me" realm. The problem is you have a lot of still possibles lurking. Oh, SA400 drives... had a problem with them and all that used that frame (sa400, 400l and 450). Seems if the spindle bearings go bad the amount of jitter on the data can exceed that of simple data seperators used with 1771 (especially RS early TRS80 with early EI). I'm sure it's possible to have the same problem with other drives. Showed up best with the SA alignment disk and a dual trace scope set up for data read EYE pattern. Allison >Thanks, >Grant

18 years, 5 months

S100 Floppy Controller Question

by dm561＠torfree.net

-------------Original Message: Date: Sun, 11 Nov 2007 19:32:38 -0500 From: "Richard A. Cini" <rcini at optonline.net> Subject: Re: S100 Floppy Controller Question Yes, I understand the 5-for-8 substitution. One of the challenges I'm having is finding a suitable disk image to try. If I get an 8" image I plan on jamming it onto a 5.25" HD disk and giving that a whirl. I made the "8"-only" distinction because one of the boards I have (the Versafloppy) has both connectors. It just saves a little time in not having to make a cable. ------------Reply: This is quite possibly not relevant to _your_ controller, but FWIW my Cromemcos have both the DD and the HD drives on the same cable, and the 50 pin connector is only used for the 'real' 8" drive. Although some of the signals have separate drivers/receivers, the 5 1/4 and 8" drives are effectively on the same bus; the only difference is that the 8" drives supply (and the FDC expects) a /READY signal on pin 22 (?) whereas the TM-100s did not supply that signal and the FDC does not look for it on the 5 1/4" cable; I suspect that's how the system distinguishes between the drives in order to select the correct speed. Modern HD drives _do_ supply a /READY signal on pin 34, although you'll probably have to change a jumper since PCs use it for Disk Change; the jumpers are in fact often labelled DC and RDY. Therefore all that is required is a jumper on the FDC from pin 34 of the 5" connector to pin 22 of the 8" (and of course any DD 5 1/4 drives must have their /READY signal disabled if it's active). The only other FDC I have any experience with is a Micropolis, and it _does_ use the /READY signal from its DD drives (although it looks for it on pin 6, which is normally DS3 or 4), so this wouldn't work. m

18 years, 5 months

VXT2000+

by Rinaldo.Eversdijk＠stork.com

Hi Henk, I'm in the Netherlands and I would like to have the unit as well. We are still using it in a sort of test environment and we have a defect power supply in one of them. We are willing to pay the shipping and additional costs. Regards Rinaldo -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Henk Gooijen Sent: zondag 11 november 2007 13:02 To: General Discussion: On-Topic and Off-Topic Posts Subject: RE: VXT2000+ Hi ?ngel, I checked the TPG website. Pity that the unit is just over 5 kilos, that would have saved 5 euro. Shipping inside Europe will be 24 euros. I have to find a good box to ship it safely ...If you are interested, send me an off-list e-mail. BTW, I have been in Granada and seen the beautiful Alhambra! thanks, Henk > Date: Sun, 11 Nov 2007 12:47:38 +0100> From: ama at ugr.es> To: cctalk at classiccmp.org> Subject: Re: VXT2000+> > Hi Henk,> > On Sun, Nov 11, 2007 at 11:45:56AM +0100, Henk Gooijen wrote:> > I am about to throw out a complete VXT2000+> > Shipping overseas is probably not worth it> > (I am in The Neterlands), but if somebody> > needs a specific part, I am willing to disassemble> > the VXT before it becomes landfill. The VXT is> > in good shape AFAIK, but can not test it ... > > I might be interested on the terminal if shipping price permits :-)> > How much could it be to ship to Granada, Spain?> > Thanks and greetings,> ?ngel> > -- > Angel Martin Alganza Tel +34 958 248 926> Departamento de Genetica Fax +34 958 244 073> Universidad de Granada mailto:ama at ugr.es> C/ Fuentenueva s/n http://www.ugr.es/~ama/> E-18071 Granada, Spain JabberID alganza at jabber.org> PGP Public key: http://www.ugr.es/~ama/ama-pgp-key> 3EB2 967A 9404 6585 7086 8811 2CEC 2F81 9341 E591> ------------------------------------------------------> () ASCII Ribbon Campaign - http://www.asciiribbon.org/> /\ Against all HTML e-mail and proprietary attachments> Please avoid sending me Word or PowerPoint attachments> http://linux.sgms-centre.com/advocacy/no-ms-office.php -------------------------------------------------------------------------- DISCLAIMER: This e-mail and any attachment(s) sent with it are intended exclusively for the addressee(s), and may not be used by, opened by, passed on to, or made available for use to, any person other than the addressee(s). Stork rules out any and all liabilities resulting from any electronic transmission.

18 years, 5 months

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