Re: tamayatech let down

On 12/26/21 9:30 PM, Doug Jackson via cctalk wrote: > "worked the last time used but no guarantees and are sold as is" > > Reminds me of the test and tag rip-off that has been embedded in > legislation. > > It was OK when we tested it at 3pm on Tuesday afternoon Your Honor. > > Gone are the days

Re: VAX 780 on eBay

On 1/2/22 11:16 AM, Jonathan Chapman via cctalk wrote: >> I'd really like 3ɸ at home for a number of different things. > > In North America? Good luck! Part of what got me to buy a smallish industrial > building was needing three phase. It's usually cheaper/easier to either use a > VFD if it's f

Re: VAX 780 on eBay

On 1/3/22 10:58 AM, Paul Koning via cctalk wrote: > The discussion about 3-phase made me check some documentation. > I also looked at some CDC 6000 series docs. Those used 400 Hz 3 phase for > supplying the CPU and peripheral logic. The CPU cabinets also take 3 phase > mains power for the com

Re: VAX 780 on eBay

On 1/3/22 1:23 PM, Paul Koning wrote: > The 6603 is highly unusual because it has 12 bit parallel data flow, rather > than bit-serial as everyone else did (until Cray went back to parallel with > the Cray 1, if I remember right). That made the 6603 very much faster, as > far as data throughput

Re: VAX 780 on eBay

On 1/3/22 6:49 PM, Grant Taylor via cctalk wrote: > On 1/3/22 4:01 PM, Chuck Guzis via cctalk wrote: >> https://twitter.com/DonaldM38768041/status/1215804561333473280/photo/2 > > Interesting series of tweets. > > I'm surprised by the tweet about Seymour Cray founding

Re: VAX 780 on eBay

On 1/4/22 7:40 AM, Grant Taylor via cctalk wrote: > I guess I thought that since Seymour left CDC to form Cray Research, > that meant that he was more of an employee at CDC and had less influence > on how it operated as a company.  I would have assumed that someone that > was a founder would have

Re: 3-phase power

On 1/4/22 10:04 AM, Paul Koning via cctalk wrote: > The other option, typically somewhat more expensive but cheaper than an > 11/780, is a rotary converter. Those are 3 phase motors, sometimes modified > a bit, driven from single phase power that construct the missing phase > somewhat like a d

Re: cctalk Digest, Vol 88, Issue 2

On 1/4/22 12:15 PM, Jonathan Chapman via cctalk wrote: > One of the top Google results: > > https://www.engineeringradio.us/blog/2012/02/the-open-delta-three-phase-service/ > > Really really, there's only two pigs on the pole. And yet, delta power, > though at a lower rating than transformer nam

3-phase power; was: cctalk Digest, Vol 88, Issue 2

On 1/4/22 3:14 PM, Jonathan Chapman wrote: >> High-leg delta is independent of open- or closed-delta. > > That's correct. > >> Open delta uses two single-phase transformers primaries connected to >> phases AB and BC. > > A to C is also valid, presumably it's rotated if there's a lot of open delt

Re: 3-phase power; was: cctalk Digest, Vol 88, Issue 2

On 1/4/22 4:04 PM, Grant Taylor via cctalk wrote: > I knew about 50 and 60 Hz and DC growing up.  I learned about 400 (?) Hz > being used in military applications about a decade ago.  25 Hz was a > surprise to me over the last year or so.  I read some interesting > things, much of it related to Ni

Re: Memory Tech you don't see very often

Perhaps even rarer were the EBAM tubes that CDC worked with during the 1970s. I recall seeing a 6' rack of a complete assembly sitting in a hallway at ADL around 1974. If CDC followed the dictates of management then, the unit was probably utterly demolsihed before being sold as scrap metal. --

Re: Memory Tech you don't see very often

On 1/6/22 10:17, William Donzelli wrote: > If you include prototypes, then you need to include ALL the prototypes > - even things made in single quantities that never worked. > > That is a HUGE amount of stuff that makes EBAM look gigantic. To be fair, EBAM received a not-insignificant amount of

Re: 8" Floppy Drives needed

On 1/12/22 12:23, Noel Chiappa via cctalk wrote: > Given how arcane the RX02 format is (sector _headers_ are written in single > density; sector _data_ is written in double) I'd be pretty surprised if > anything except an RX02 can do it. True that--however, a flux transition-type controller, such

Re: IBM Model C typewriter

On 1/12/22 19:25, Grant Taylor via cctalk wrote: > On 1/12/22 5:49 PM, Van Snyder via cctalk wrote: >> I have an old IBM Model C typewriter. I can't bear to throw it away, >> even though it doesn't work well. The carriage doesn't advance, and the >> A key doesn't work. Do you know how to tune it up

Re: IBM Model C typewriter

On 1/12/22 20:16, Grant Taylor via cctalk wrote: > That's a mailing list, not a newsgroup. > > But it is likely to be more active than the free.typewriters newsgroup. Picky, picky picky... The old Golf Ball Typewriter Shop list is long gone, and this was suggested as an alternative. --Chuck

Re: WARNING: Clear QIC Tape Bands

On 1/18/22 07:33, Jonathan Chapman via cctalk wrote: > https://i.imgur.com/48EfOQG.jpg > > That's after sitting parked a couple months. I have a Dysan doing it too. The > Dysan had been re-banded with a boiled 3M band and run for years like that > with no shedding. I have another Dysan with a gr

Re: WARNING: Clear QIC Tape Bands

On 1/18/22 11:38, Zane Healy via cctalk wrote: > > >> On Jan 18, 2022, at 10:09 AM, Jonathan Chapman via cctalk >> wrote: >> >>> My opinion is that if you're trying to use DC carts for archival >> storage, you should have your (tape) head examined. >> >> Not archival storage, just day-to-day op

Re: WARNING: Clear QIC Tape Bands

On 1/18/22 22:32, Alan Perry via cctalk wrote: > > On 1/18/22 8:22 AM, Chuck Guzis via cctalk wrote: >> You should be warned that Plastibands >> do deteriorate after a year or so--I have a package of them that cannot >> be stretched without breaking. >> > >

Re: Typing in lost code

On 1/23/22 10:16, Paul Koning via cctalk wrote: > Maybe. But OCR programs have had learning features for decades. I've spent > quite a lot of time in FineReader learning mode. Material produced on a > moderate-quality typewriter, like the CDC 6600 wire lists on Bitsavers, can > be handled t

Re: Question about DECtape formulation

On 1/24/22 11:05, Paul Koning via cctalk wrote: > Looking at that spec some items pop out. > > The coating is quite thin, much thinner than the backing. Not too surprising > actually, if it were thick it would reduce the max possible bit density. > > There is a coating wear spec (as a ratio of

Re: Question about DECtape formulation

On 1/24/22 11:50, Paul Koning wrote: > > I thought Black Watch has coating on the back, as others mentioned. DECtape > is not black but brown, so graphite doesn't seem to be involved. I grabbed a reel of BW out of my stash and you're correct--the black is on the back. Still, I can see where a

Re: Question about DECtape formulation

So, can we assume that the words about a "tape sandwich" refer to a mylar base, oxide coating, and a lubricant/protective coating? That is not an oxide coating sandwiched between to layers of mylar. There was such a tape construction, used on the Datamatic 1000. (ca. 1955) --Chuck

Re: Question about DECtape formulation

On 1/25/22 06:18, Paul Koning via cctalk wrote: > > >> On Jan 24, 2022, at 10:27 PM, Gary Oliver via cctech >> wrote: >> >>> ... >> >> As to the real reason I was doing this: Most of my tapes are un-boxed and >> have suffered being in a dusty area (before I got them) with the dust >> forming

Re: Question about DECtape formulation

On 1/25/22 14:06, Gary Oliver via cctalk wrote: > My search results were dominated (even with 'advanced search') by Amazon > and Ebay (naturally) but also by a couple of vendors (Cricut as example) > and I never found anything coming up for .10 inch or equivalent in mm.  > This appears to be .10 i

Re: Origin of "partition" in storage devices

The IBM 1620 Monitor IID, partitioned the 1311 into various areas. I can probably find other old examples. --Chuck

Re: Origin of "partition" in storage devices

Note also, that tapes can be partitioned per ANSI T10. ---Chuck

Re: Origin of "partition" in storage devices

There's also hardware partitioning. Back in the bad old days of the 5160 PC, some DTC controllers allowed for partitioning a drive (using witch settings) into two smaller drives. I don't recall the exact BIOS revision (BXD05?) where this came into play, but I have the manual. --Chuck

Re: Origin of "partition" in storage devices

On 2/1/22 09:16, Mike Katz via cctalk wrote: > In the rotating drive world there is constant linear velocity (CLV) and > constant angular velocity (CAV) drives. > > On CLV drives the speed of rotation would vary based on the track > (slower in the inner tracks and faster on the outer tracks).  Thi

Re: OT: Who? What? Was: Re: Origin of "partition" in storage devices

On 2/1/22 13:40, Paul Koning via cctalk wrote: > > With MSCP, DEC switched to addressing disks by sector offset, as SCSI did > later, rather than by geometry (cylinder, track, sector) on devices like the > RK05 and RP06. If the OS sees only an LBA, it doesn't matter whether the > drive uses z

Re: Odd jumpers on a XT 2190 drive.

On 2/5/22 17:13, Jerry Wright via cctalk wrote: > I'm going through  a few of my ESDI  and MFM hard drives  and ran across 2 > Maxtor  XT 2190 drives with  all of the Drive Id's (1-4) tie together with 1 > long > jumper and the drives have the write protect jumper is installed.  Not sure > what

Re: DEC Tape TU56 head pictures

On 2/9/22 12:44, Gavin Scott via cctalk wrote: > On Wed, Feb 9, 2022 at 10:11 AM Mike Katz via cctalk > wrote: >> I'm still not sure how to clean the front of the head where the tape >> touches the head. Any ideas? > > Back in the day there was "Tape Head Cleaner" Which was a little tin > of tri

Re: Retro Chip Tester Pro, done!

On 2/10/22 09:11, dwight via cctalk wrote: > I hope you are not thinking it would test an Intel 4004 or a 8008? That would > be a stretch. For the 4004, there is only a narrow range of frequencies it > runs under. I'm not that familiar with the 8008 but suspect it has similar > restrictions. Bot

TTL substitute for DTL

I've got a piece of gear here with a bad MC858P used as a bus driver--terminated in 220/330 ohms at the far end. Given that old DTL is a hit-or-miss proposition, I'm proposing to substitute a 7438 OC buffer. Pinout's the same, as is Vcc. Before I get out the soldering iron, any "don't do it" tho

Re: TTL substitute for DTL

On 2/10/22 22:39, Brent Hilpert wrote: > On 2022-Feb-10, at 9:50 PM, Chuck Guzis via cctalk wrote: > >> I've got a piece of gear here with a bad MC858P used as a bus >> driver--terminated in 220/330 ohms at the far end. >> >> Given that old DTL is a hit-or

Re: VAX9000 unearthed

On 2/20/22 10:10, Mark Kahrs via cctalk wrote: > I heard Butler Lampson once exclaim that ECL design was in some ways easier > than TTL. If you terminated every line, you get controlled impedances with > controlled edges. This was the design philosophy for the Dorado. Indeed--ECL WW prototype bo

Re: Installing an operating system on the 11/83 - update.

On 2/22/22 15:33, js--- via cctalk wrote: > > Rod, > >   Not sure an RX33 (if 1.2MB equivalent) would write working RX50 800k > (double density) disks.  Very different drives. I've copied RX50 disks for a customer. 96 tpi 80 cylinder single-sided, 10 x 512 byte sectors. You should be able to

Re: Installing an operating system on the 11/83 - update.

On 2/22/22 16:12, js--- via cctalk wrote: > As Chuck noted, I'd think you'd want to use 360K media -- not DSHD > diskettes... and ensure that the 1.2MB drive is slowing down to 300RPM > with a data rate of 250KHZ. > > These features will depend on the 1.2MB drive you have, as well as your > FDC a

Re: Installing an operating system on the 11/83 - update.

On 2/22/22 19:43, Jay Jaeger via cctalk wrote: > Writing a 360KB or RX50 diskette with a 1.2MB drive is a path to a lot > of frustration.  Not only do you have to double step the drive (software > often takes care of that part), but the tracks written will be narrower > than a real RX50 / 306KB dr

Re: 11/83 operating system load update -2

On 2/23/22 09:43, Paul Koning via cctalk wrote: > I don't know PUTR, but my experience with DOS int13 code in RSTSFLX (built > with DJGPP) is that it worked fine in a DOS window on Win95. And that makes > sense, because Win95 is basically just a bit of UI veneer over DOS. Win NT > is an entir

Re: DEC VT52 CRT anode connection

On 2/23/22 17:25, Chris Zach via cctalk wrote: > Pretty much. I took apart my VT52 about 2 years ago because it wasn't > happy. Turned out the +5 and +15 volt supplies were good but the -15 was > bad. > > After fiddling around with capacitors and transistors I took the easy > way out and just put

Re: DEC VT52 CRT anode connection

On 2/23/22 18:17, Doug Jackson via cctalk wrote: > Hmm - Depends on where that pesky ground connection is put :-) (Duck) Well, if you stand on your head whilst soldering it in, it's all good! :)

Re: Information about an unknown IC

>> On 2022-02-24 9:29 a.m., Clemar Folly via cctalk wrote: >>> Hi >>> >>> I'm looking for information about Texas Instruments TB-759933 IC. >>> >>> Does anyone have the datasheet or any other information about this IC? >>> >>> Thanks. >> >> What is the native habitat of this chip? Mother board, I

Re: Rack Discussion Continued - Slide lubricant

Hitchhiking on Mike's thread, There's a question that I've wondered about regarding rack slides. Right now, for a couple of tape drives, I'm using slides rated at 150 lbs., yet they seem pretty flimsy when compared the the old heavy-duty slides we used to use. Has anyone tried using the standard

Re: Rack Discussion Continued - Slide lubricant

On 3/2/22 13:35, W2HX via cctalk wrote: >> then grease them with light, white lithium grease. > Fully agree! If you wanted something a bit cleaner and less prone to separation, I'd suggest Boeshield T9. Great stuff, but more expensive than lithium soap in oil. --Chuck

Re: Looking for computer and individual to read old floppy disks

I could do it, but I'm a little squeezed for time and energy right now. Spending my mornings under the LINAC. --Chuck

Re: Looking for computer and individual to read old floppy disks

On 3/11/22 18:32, Warner Losh via cctalk wrote: > There are no 5.25" USB floppies. Well, not 100% true (there are > values in the identifier strings that tell you it's a 1.2MB floppy vs > a 1.44MB floppy), but as a practical matter, you can't find them. > I've looked and gave up... That's how I wo

Re: Looking for computer and individual to read old floppy disks

On 3/11/22 18:04, Bill Gunshannon via cctalk wrote: > It was mentioned that he would pay someone to do this.  Why not just > tell him to buy a $20 USB Floppy from Amazon and copy them himself? If he wants, he can send them to me. After all, it's just a few keystrokes for me. However, I don't d

Re: Looking for computer and individual to read old floppy disks

On 3/11/22 19:57, Fred Cisin via cctalk wrote: > There was a time about 30 years ago, . . . > a couple different companies took tiny single boards, such as Ampro > Little Board, stuck them in a box with a floppy drive, and custom > software that included communication through serial port, and mark

Re: Commodore vic 20 poweroff

On 3/16/22 13:37, Will Cooke via cctech wrote: If the question is being asked by a person of a certain vintage, I can understand the "why" of it. Gone are the days when you simply switched off the AC power when you were finished. Nowadays, everything from cell phones to Smart TVs go through a shu

Re: Does anyone/museum test disk packs?

On 3/16/22 18:25, John Herron via cctalk wrote: > I was visiting a new thrift store and saw a disk pack they had. I joked > that mine are just fun display/conversation pieces. > > Do the giant drives suffer the same head crash issues that a bad zip disk > can do or are these safe if someone actual

Re: ID UV erasable PROMS used on an IBM PC board?

The PROMs are most likely house-labeled Intel commodity parts with JEDEC-standard pinouts, so it should be fairly easy, using an EPROM reader, to figure out if these are 8KB, 16KB, 32KB or 64KB devices. I suppose one could find representative known Intel samples and compare the appearance "under t

Re: ID UV erasable PROMS used on an IBM PC board?

On 3/22/22 21:32, dwight via cctalk wrote: > Years ago when I was at Intel, they would take EPROMs that had only a few > defects and attempt to program them with specific applications. They would > then usually paint the window black and put on that particular product > number. When we needed EP

Re: ID UV erasable PROMS used on an IBM PC board?

On 3/23/22 08:18, Christian Corti via cctalk wrote: > On Wed, 23 Mar 2022, Chris Elmquist wrote: >> More interesting.  If the programming algorithms remained the same then I >> guess it is just an issue for the programming system--  when it auto-IDs, >> it should display (and allow!) 27C256A instea

Re: Glass memory?

Wasn't some of this glass delay line memory used in early raster-scanned computer video displays? --Chuck

Re: Glass memory?

On 4/1/22 10:27, Paul Koning wrote: > > >> On Apr 1, 2022, at 1:25 PM, Chuck Guzis via cctalk >> wrote: >> >> Wasn't some of this glass delay line memory used in early raster-scanned >> computer video displays? > > I don't know about th

Re: Fanuc PPR - Paper Tape Punch, Printer and Reader : Not quite working

On 4/9/22 17:26, Martin Bishop via cctalk wrote: > Bill > > Thanks for the offer of the DosTek 440a. However, my problem is getting the > 232 output to wiggle a CRO not to input and log the serial data. > > Fanuc manuals 1788.pdf, on VintageComputer.net, looks as though it contains > more deta

Re: Fanuc PPR - Paper Tape Punch, Printer and Reader : Not quite working

On 4/10/22 11:08, Martin Bishop wrote: > Chuck > > Thank you for the parallel port suggestion. I followed it up by opening the > D-25 and reviewing the wiring. It looks very RS232 to me, the pin out I > found is detailed in my 10 1314A Apr 22. That the punch and reader respond > to RS232 inp

Re: Fanuc PPR - Paper Tape Punch, Printer and Reader : Not quite working

On 4/10/22 12:23, Martin Bishop wrote: > Chuck > > My error, you said 20 mA current loop, I bowdlerised it as parallel port. I > have a punch with a parallel interface ... I can't recollect ever using a > current loop interface on equipment, although I have met many in old > documents. 4 ..

Re: Retro networking / WAN communities

On 4/12/22 10:44, Todd Goodman via cctalk wrote: > To me a hub is a layer 1 device (physical layer) that doesn't look at > the traffic at all while the bridge does look at the traffic and > generally implements 802.1d Spanning Tree Protocol and processes BPDUs. Hub is a nebulous term. For examp

Re: Retro networking / WAN communities

On 4/12/22 12:24, Grant Taylor via cctalk wrote: > Details matter. I'll bow to the experts and refer to the things as a "boxes with n capabilities". That should pretty much cover the terrain. --Chuck

Re: idea for a universal disk interface

I'll only mention that there were ICs that could interface to both MFM/ST506 hard drives as well as floppies (System/3 MFM). An example would be the SMC HDC9234, "Universal Disk Controller". Pretty cool chip for the time; has full 24 bit DMA address capability. But different register/controller s

Re: idea for a universal disk interface

On 4/14/22 16:26, Fred Cisin via cctalk wrote: > On Thu, 14 Apr 2022, John Foust via cctalk wrote: >> Magnetic visualizers also discussed here: >> http://qicreader.blogspot.com/p/track-visualization.html > > Thank you. > > That is what I was looking for. > It doesn't imply current existence of an

Re: Advice on Desoldering an IC

For very-difficult de-soldering, I use a variation on the Chip-Quik idea. I take a hunk of Cerrobend 158 fusible alloy and a file and make a small pile of powder from it. I then pack the powder around the pins of the IC to remove and heat the area using the light from a 75 watt PAR-38 halogen re

Re: Advice on Desoldering an IC

On 4/15/22 17:12, W2HX wrote: > Just be careful around cerroblend. According to Wikipedia... > > "... is a metal alloy that is useful for soldering and making custom metal > parts, but which is toxic to touch or breathe vapors from." > "...is toxic because it contains lead and cadmium, and conta

Re: Replacement BOT/EOT markers for 1/2" tape

On 4/18/22 09:59, Bjoren Davis via cctalk wrote: > Hello Retrofolks, > > I have a 1/2" 9-track magtape which is missing a BOT marker. > > Does anyone have a recommendation for a reflective tape to use to > replace the BOT marker? > > I was looking at > https://www.amazon.com/Metalized-Polyester-

Re: Intel VS Motorola (Was: interesting DEC Pro stuff on eBay

On 4/21/22 15:14, Fred Cisin via cctalk wrote: > On Thu, 21 Apr 2022, Mike Katz via cctalk wrote:>> Intel has never understood > interrupts or good cpu architecture. >> Look at the segment:offset architecture of the 8086 and of course it's >> single interrupt (without the separate interrupt contro

Re: PCI floppy controller

On 4/21/22 16:47, Charles Dickman via cctalk wrote: > Were there ever any floppy controllers for the (parallel) PCI bus? I > Googled a bunch and haven't found any. > > I am trying to outfit a computer for the long haul that can run a bunch of > older software in virtual machines and do things like

Re: PCI floppy controller

On 4/21/22 18:01, Charles Dickman wrote: > On Thu, Apr 21, 2022 at 8:02 PM Chuck Guzis via cctalk > I was at that point and looking at DP3T switches to have an external > connection as well. DP3T switches are mess. You could also bring the floppy cable out to a standard DC-37 conne

Re: PCI floppy controller

On 4/22/22 04:44, Liam Proven via cctalk wrote: > The company did a range of parallel-port storage drives: CDs, tape > drives and so on. Most were slow but worked, but the floppy drives > were quite a good option at the time for things like laptops which > couldn't accept another drive or controll

Re: Selling my 026/029 IBM punch card control drum ($150)

On 4/22/22 14:37, Lee Courtney via cctalk wrote: >> Works fine. Good Condition. > > Doesn't say whether it includes power cord or not? You'd figure that there would be buckets of these things around. Many keypunch pools would have several of them for each keypunch, preloaded with cards for appr

Re: PCI floppy controller

On 4/22/22 15:47, Maciej W. Rozycki wrote: > On Thu, 21 Apr 2022, Chuck Guzis via cctalk wrote: > >> I suppose it might be possible to fashion a legacy floppy controller on >> a PCI card with enough supporting logic to make it compatible with >> existing software, but

Re: PCI floppy controller

On 4/22/22 18:43, Bill Gunshannon via cctalk wrote: > I guess I'll find out.  I just ordered one.  Shipping is almost as much > as the device. :-( > > Still think I will look into what it would take to access floppies > from an Arduino.  They're fun to play with, too. As far as I am aware, none

Re: PCI floppy controller

On 4/23/22 07:16, Liam Proven wrote: > On Fri, 22 Apr 2022 at 23:41, Chuck Guzis wrote: >> >> Take a look at the chip (DP8473) datasheet. It boasts direct (no >> buffer needed) support of up to 4 drives. The rest is software; the >> protocol is pretty much write some registers before/after >>

Re: P112 Floppy Controller

On 4/23/22 13:12, Fred Cisin via cctalk wrote: > On Sat, 23 Apr 2022, Craig Ruff via cctech wrote: >> The P112's floppy controller is the one in the SMSC FDC37C665IR >> SuperIO chip. The data sheet states it is a 2.88 MB "Licensed CMOS >> 765B Floppy Disk Controller" and claims 100% IBM compatibili

Re: Slashed letter O, unslashed letter zero

On 4/26/22 10:48, Warner Losh via cctalk wrote: > On Tue, Apr 26, 2022 at 11:25 AM Shoppa, Tim via cctalk < > cctalk@classiccmp.org> wrote: > >> This website has a history of slashing the letter O (and also ticked, >> center-dotted, etc.) oriented around computing: >> https://circuitousroot.com/ar

Re: Slashed letter O, unslashed letter zero

On 4/26/22 12:44, Fred Cisin wrote: > One of my cow-orkers, a programmer, insisted that it was much faster for > him to type as he composed, even on a 026, than it was to write on > coding sheets, and then hand it off. There is something to that. Many was the time that I'd be punching late at n

Re: Slashed letter O, unslashed letter zero

On 4/26/22 13:41, ben via cctalk wrote: > PS: Did any common I/O devices have the ALGOL symbols Less than or > Equals, Greater than or equals , not , arrows and other misc symbols? > CDC Display code certainly started out that way. See https://en.wikipedia.org/wiki/CDC_display_code. If you wa

Re: Slashed letter O, unslashed letter zero

On 4/26/22 19:05, Fred Cisin via cctalk wrote: > I remember about 30 years ago, a registration card for a Microsoft > product had specific forms that they wanted for certain letters, for the > sake of a slightly inadequate handwriting recognition program.  Among > those was "ticked letter O".  A ro

Re: Slashed letter O, unslashed letter zero

On 4/26/22 20:10, ben via cctalk wrote: > On 2022-04-26 8:48 p.m., Chuck Guzis via cctalk wrote: > >> CDC actually adopted OCR-A as their official internal font.  My office >> typewriter (Olivetti) had such a font.   I hated it. >> > > Well you can't have t

Re: Slashed letter O, unslashed letter zero

On 4/27/22 12:38, Diane Bruce wrote: > Yes. Now try Courier ;) That Model D had magnificent typefaces; it was proportionally-spaced. The space bar was split in the center--one side gave you an "em" space (wide); the other gave you an "n" space (narrow). When backspacing to correct, it was a bi

Re: Not just slashed zeroes/ohs

On 4/27/22 10:51, Craig Ruff via cctech wrote: > Having gone through many mathematics courses it was common to also place a > slash on the letter Z to distinguish it from the numeral 2. Also for persons > from Europe where they slashed the numeral 7 to distinguish it from a numeral > 1 that comm

Re: cleaning up edge connectors

On 4/28/22 12:47, Bill Gunshannon via cctalk wrote: > > I am hoping to restore my TRS-80 Model-I(s).  As is usually > the case with these the edge connectors are badly corroded > and dirty and cleaning them with an eraser really doesn't > help much.  Back in the day there used to be something you

Re: cleaning up edge connectors

On 4/28/22 12:47, Bill Gunshannon via cctalk wrote: > > I am hoping to restore my TRS-80 Model-I(s).  As is usually > the case with these the edge connectors are badly corroded > and dirty and cleaning them with an eraser really doesn't > help much.  Back in the day there used to be something you

Re: cleaning up edge connectors

On 4/28/22 13:56, John Foust via cctalk wrote: > Not cheap but they are out there. > > https://www.goldplating.com/collections/jewelry-plating-kits > > I had a similar set of jars of metal salts for plating 40+ years ago. > > - John Another favorite place for plating supplies: https://caswel

Re: PCI floppy controller

On 5/5/22 17:44, Charles Dickman wrote: > On Thu, Apr 21, 2022 at 10:34 PM Chuck Guzis > wrote: > > On 4/21/22 18:01, Charles Dickman wrote: > > On Thu, Apr 21, 2022 at 8:02 PM Chuck Guzis via cctal > > I was at that point and looking at DP3T switches to have

Anyone looking for 230V fans?

I don't know if this applies to any here, but I note that Electronics Goldmine has some Papst 230V 135mm fans for sale. These would be NOS: https://www.goldmine-elec-products.com/prodinfo.asp?number=G26421 FYI Chuck

Re: Replacement for a DEC 7474 Chip

On 5/14/22 15:35, dwight via cctalk wrote: >>> You are stuck with using an original 7474 family assuming this is driving >>> other early TTL. 74LS74, and others simply don't have the drive capability >>> to work. >> I know LS has less fanout, but is it not able to drive plain 74xx at all? >> T

Re: Replacement for a DEC 7474 Chip

On 5/14/22 23:04, ben via cctalk wrote: > Faster is not better, bigger is bett... ops wrong topic. > > 74H while slower, and 74S tend to have reliable delay times looking at > gates with min to max delays < 3 ns. This helped devices to track > the same speed across a system. > A 74ABT00 is 1 to 4

Re: Replacement for a DEC 7474 Chip

On 5/15/22 01:16, Eric Smith via cctalk wrote: > I don't think that worked on any TTL (or CMOS) 74x74 flip flops, except > maybe by accident if you shorted the output enough to draw Vcc down (or > ground up) enough to disrupt the FF, and then you have other problems. Checking my old Moto databook

Re: PL/M & CP/M

Are you talking about this? https://web.archive.org/web/20131110002247/http://www.nj7p.info/Common/Toys/Software/OS/work/IntelTools.zip (Courtesy of Mark Ogden) --Chuck On 5/30/22 15:06, Bill Gunshannon via cctalk wrote: > > Recently in my wanderings on the web I saw a comment(I don't > rem

Re: PL/M & CP/M

On 6/7/22 00:30, Hector Peraza via cctalk wrote: > In the late 80's I disassembled a PL/M compiler I got in paper tape and > ported it to CP/M. Then stored it in a cassette tape, then lost it, then > about 8 years ago found it again and recovered it. The compiler had no > indication whatsoever of

Re: I can't sent to gmail either with my domains

On 6/20/22 16:58, jim stephens via cctalk wrote: > > not sure what needs to be done either.  Maybe Jay's having problems with > that.t > > Sending this along to see if my non google  related post goes thru. > google folks apparently won't get it. gmail recently switched their security to OAuth2.

Re: Xerox 800 Word Processor 1974 promo film

Also, Fuji Xerox in Japan, ca. 1962, initially a distributor of Rank Xerox products. For quite awhile, many of Xerox-branded small office copiers, were, in fact, made by Fuji. As of last year, Fuji (Fujifilm) has gone its own way, devoid of the Xerox tie-in. https://en.wikipedia.org/wiki/Fuji_Xe

Re: Xerox 800 Word Processor 1974 promo film

On 7/2/22 08:44, Nigel Johnson Ham via cctalk wrote: > I remember hearing it in the UK before I emigrated to Canada - maybe it > was  a regional thing. > > I certainly saw a British telephone in one of the shots! J. Arthur Rank and his big gong. Veddy British! --Chuck

Re: Xerox 800 Word Processor 1974 promo film

On 7/10/22 13:41, Paul Koning via cctalk wrote: > > >> On Jul 10, 2022, at 4:10 AM, Christian Corti via cctalk >> wrote: >> >> On Sat, 2 Jul 2022, Grant Taylor wrote: >>> I don't know that I've ever heard / seen the name "Rank" prefixing "Xerox" >>> before. >> >> Actually I knew them only as R

Re: List migration

On 7/11/22 16:25, David Griffith via cctalk wrote: > > My reply is at the bottom.  Please put your reply there too. > On Mon, 11 Jul 2022, Dennis Boone via cctalk wrote: >> Friends, >> >> The process of migrating the cctalk and cctech mailing lists to a new >> host in Chicago is underway.  This ev

Re: Floppy Cables & "twists"

On 7/12/22 22:08, Dave Dunfield via cctalk wrote: > After recently selling my ImageDisk system, and having a few spare older PC... I ran into a similar situation with a newer-than-P3 single-drive motherboard. I'd switch from the internal 3.5" 1.44M drive to an external 5.25" 360K drive.It tur

Re: Floppy Cables & "twists"

I'll add that just switching the motor and select lines does mean that both the internal drive and the external drive must have termination on all the other (input) lines. That probably accounted for my "too low drive current" issue. You could switch all of the lines, but that may be easier said

Re: cctalk Digest, Vol 94, Issue 20

On 7/16/22 10:00, Jan Mleczko via cctalk wrote: > Dziękuję za twoją wiadomość. Przepraszam, jestem na wczasach i odpowiem > później. For those not conversant in Polish, he said he's on vacation/holiday and will answer later. FYI, Chuck

Re: cctalk Digest, Vol 94, Issue 20

On 7/16/22 12:30, Bill Gunshannon via cctalk wrote: >> For those not conversant in Polish, he said he's on vacation/holiday and >> will answer later. >> >> FYI, >> Chuck > > Dziękuję. > Nėr už ką --Chuck

  1   2   3   4   5   6   7   8   9   10   >