test-drb

test-drb@ccmp.vtda.org

101090 discussions

by ploopster＠gmail.com

I'm looking for an IBM Thinkpad 701C or 701CS (the one with the butterfly keyboard), as well as a Thinkpad 860. Anyone have any available? They have to be working. Peace... Sridhar

18 years, 4 months

Homebrew Drum Computer (magnetic heads)

by bnansel＠bigpond.net.au

Tue Dec 18, 2007 at 17:32 Gordon JC Pearce said: > Did any company ever actually produce a storage product that used > 8-track carts (or indeed broadcast carts)? Did it work? > > Gordon I had a surplus dual 8-track data drive back in the early '80s that came from a Compucolor machine, ca. 1975. It was fun to play with. As I recall, it had a 4-track head and two head positions. I managed to write & read data from it at 2400 baud. I don't know if it would have worked at a higher data rate, though the manufacturer claimed it would work at up to 600 cps. -Bobby

18 years, 4 months

Membranes in Keyboards

by dmc_67301＠yahoo.com

I have an old Xerox memorywriter electronic typewriter that needs to have the membranes inside the keyboard replaced. Does anyone out there know how to replace the membranes? I have two keys that no longer work because of this problem. Thanks. --------------------------------- Never miss a thing. Make Yahoo your homepage.

18 years, 4 months

Burroughs C3660 Electronic Calculator

by broche＠tcn.net

Hi, all: I'm a newbie to the list, so hello. I'm trying to fnd out the fair market value of a Burroughs C3660 Electronic Calculator, c/w manuals, magnetic memory cards, etc. Can anyone give me their opinion, or point me to a web site which gives market values? Best Wishes, Bernie Roche Toronto, ON, Canada

18 years, 4 months

HD 5.25" floppy disk drives emulating legacy DSQD floppy disk drives

by lynchaj＠yahoo.com

Hi, Sorry for the long post. I have done a lot of things to make this work but am still stuck on this problem. As some of you know, I and some others have been busily working on restoring some Vector Graphic machines. One goal is to replace the Tandon TM100-4M 100tpi drives with more commonly available High Density 96tpi floppy drives. I realize the disks between the two types of drives are incompatible and I plan to retain both types of drives for compatibility with other Vector Graphic machines. However, the 100tpi drives are difficult to obtain and I would like to limit their use to preserve their remaining lifespans. I would like to transition my regular usage disks to the HD 96tpi drives to utilitize commonly available and inexpensive HD floppy drive mechanisms. I believe it is possible to make an HD drive emulate a legacy DSQD drive -- at least I am sure it can be done on the PC. The late Don Maslin was apparently able to use 720K (DSQD) 5.25" floppy drives on his Vector Graphic system (see link below). I would like to do a similar thing but using the HD drives in DSQD emulation mode. http://www.classiccmp.org/pipermail/cctalk/1998-January/093114.html I have a couple of HD floppy disk drives such as the Panasonic JU-475 and TEAC FD-55GFR. I have jumpered and modified both drives so that the spindle motor turns at 300 RPM which I have verified using a fluorescent lamp and tach wheel. I have set the jumpers or directly wired to ground Pin 2 to force Double Density mode. I have covered Pin 2 on the interface with tape so that it does not interfere with the FDC on my Vector Graphic machine and vice versa. According to the schematic of my Vector Graphic integrated FD/HD controller (FDC) neither pin 2 (density select) nor pin 34 (/ready) are used. After many tests and inspections, I have verified both HD drives do work in 720K DSQD emulation mode on my floppy test bench PC. They are configured as 3.5" 80 track drives. The motor spins at 300 RPM and they are both able to format and verify with scandisk under MS-DOS using good quality 5.25" disks. The problem comes in when I attach either HD drive to the Vector Graphic FDC. Whenever it tries to format under CP/M, the VG is able to write out all 154 tracks (I have verified it is writing the tracks by inspecting the disks using my Catweasel) but the VG cannot verify the tracks correctly and fails the format. Everytime it tries to format a disk, it ends with "PERMANENT DISK ERROR" messages. Using different CP/M utilities to write to the HD drives results in similar errors such as VG BACKUP, a disk copy utility, and CPYFSTU, another CP/M disk copy utility. I do not know for certain whether the disks are have errors when written or the drive is having problems reading the track. I know the disks are good as I can format them on the VG using the TM100-4M drive without issue. When I verified the tracks are written using the Catweasel and the same disk and drive I noticed several read errors and bad sectors which implies the tracks were written with errors. Does anyone know why these HD floppy drives are incompatible with the Vector Graphic FDC? Is there something I am missing or some setting which would make them compatible? The HD drives work just fine at DSQD drives on the floppy test bench PC so I am fairly sure the drives themselves are OK. The VG FDC works fine with the TM100-4M drives so I think they work OK. The problem is only when I attach the HD drives to the VG FDC. Would anyone please give me some insight on this problem? Thank you in advance for any help. Andrew Lynch

18 years, 4 months

Yet another VT-100 emulator

by dave06a＠dunfield.com

>> Does anyone know if any of the more modern (ie: VGA) cards support >> enhanced >> 132 column text modes? > >I think this is a "maybe". At [ >http://www.columbia.edu/~em36/wpdos/textmode.html ], there's a link to a >program that scans for a series of 132-column VESA text modes. It couldn't >find any on the laptop I tried it on (no surprise), but apparently there are >a number of NVIDIA cards that support these modes. I don't know what how >the layout compares to the character/attribute pairs for 80-column modes, >but here's the Pascal code they use to try entering the modes: Thanks! - that was useful. Turns out many of the cards I have support a 132x25 column video mode which is laid out exactly the same as the 80 column modes except for being 264 bytes per line instead of 160 (character and attribute pairs). For my ATI cards mode 35 (23h) seems to work on most of them. I've just posted a new version of LAPTALK, which supports 132 column mode. In order to enable it, you must configure the 132 column video mode under "General Parameters". 0-255 are standard BIOS modes, and 256-511 are VESA modes (sorry, but you have to set the mode in decimal). It also supports set/reset "column" (132 column) mode now (if the mode is configured). I've also added a small FIND132.COM utility to the package which helps find that elusive 132 column video mode. I've also added a 132 column test to the VTEST.COM utility, Other improvements in this version: - Improved the keyboard mapping function, including a visual layout showing where the 103 keycodes I support occur on a generic keyboard. - "auto-repeat" is now configurable, and set/reset mode works. - Configurable Device Attributes value sent back to host. Dave -- 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, 4 months

digital camera capabilities

by cclist＠sydex.com

On 19 Dec 2007 at 8:41, cctalk-request at classiccmp.org wrote: > From: "Roy J. Tellason" <rtellason at verizon.net> > Unfortunate as in it wasn't directly accessible then? I thought that the > point of such a setup was to keep a file accessible in digital form. Or > is that some sort of offline storage, like punched cards? It depended on your idea of "accessible". It was "accessible" on the scale of, oh, say, a book requested through inter-library loan is "accessible". Make a request, find a good Russian novel to read and hope your file hasn't been lost. There was a very-much-frowned-upon program that was popular among users to open and close every single file cataloged under your account just to avoid the dreaded Photostore. The 1360 was very typical of the wonderful Rube Goldberg-style of mechanical engineering that IBM was capable of. Second perhaps only to the 3850 MSS or the 2321 DCD. Certainly in a different league >from the competition (e.g., NCR CRAM), although the ill-fated CDC SCROLL comes close... Cheers, Chuck

18 years, 4 months

have you seen www.fortran.com?

by tsw-cc＠johana.com

On Tue, 18 Dec 2007 , Fred Cisin <cisin at xenosoft.com> wrote: > > > A REAL programmer can write a FORTRAN program in any > > > language. > > On Tue, 18 Dec 2007, Chris M wrote: > > O man don't tell me that means a *real* pwogwammer > > knows how to use the <TAB> key. Or spends half his > > coding time running the spacebar. > > of course not > you punch a drum card No, you have the "standard" drum card already punched up. You keep them right below the chad box in the keypunch so that the students who muck up the "standard" one in their crazy attempts to make their own can be put out of their misery. Always keep a few "extras" floating around. Of course, the "standard" drum card has Fortran as the #1 program, and the assembler of the machine in the #2 program. This usually indicated you had the statement number LEFT justified in columns 1-5, not any of that coding form right justified junk. As for Greenbar/bluebar (I always thought bluebar was better), weren't those the coding forms we all used. Having nice wide paper was where you made the "edits" to your code and took it to the keypunch. Ob Keypunch: Back in the day they had a Control Data Institute ad on TV that boasted "Do you like working with your hands and not getting your fingernails dirty?", I then remarked that this guy has NEVER replaced a keypunch ribbon. (*SIGH*) those days were much more fun!! ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

18 years, 4 months

RQDXn to RX33 / RX50 cable construction

by tiggerlasv＠aim.com

While perusing the 'net the other day, I stumbled across details for a cable to go directly from an RQDXn controller to a hard drive. I didn't find any mention of a cable to go from an RQDXn to a floppy. Since I have a BA123, and ONLY use the RQDX3 for floppy support, I thought it might be a handy cable to have, rather than going through the tangle of cables involved with the RQDX "Paddle card". It might also come in handy for testing. If anyone is interested, here are the pinouts, and instructions for constructing such a cable.? The instructions were created with the lay-person in mind.? Copying this text into Windows Notepad should restore proper formatting. This cable was constructed using a BA23 distribution panel as a guide, and has been tested with both RX50's and RX33's, attached to an RQDX3. Cable diagram: Floppy? RQDX??? Description --------------------------------- 1?????? 21????? Gnd 2?????? 22????? Density Select --------------------------------- 3?????? NC????? (Cut) 4?????? NC????? (Cut) 5?????? NC????? (Cut) --------------------------------- 6?????? 24????? Drive Select 4? 7?????? 25????? Gnd 8?????? 26????? Index 9?????? NC 10????? 28????? Drive Select 1 --------------------------------- 11????? NC????? (Cut) 12????? 29????? Drive Select 2 13????? NC????? (Cut) --------------------------------- 14????? 30????? Drive Select 3 15????? NC 16????? 32????? Floppy Motor 17????? 33????? Gnd 18????? 34????? Direction 19????? 35????? Gnd 20????? 36????? Step 21????? 37????? Gnd 22????? 38????? Floppy Write Data 23????? 39????? Gnd 24????? 40????? Write Gate 25????? 41????? Gnd 26????? 42????? Track 0 --------------------------------- 27????? NC????? (Cut) 28????? 8?????? Write Fault --------------------------------- 29????? 45????? Gnd 30????? 46????? Floppy Read Data 31????? 47????? Gnd 32????? 48????? Head Select 0 33????? 49????? Gnd 34????? 50????? Ready Stuff you'll need: 1.)???? A suitable length of 34-conductor ribbon cable. ??????? Make sure you have enough wire to reach the controller, ??????? and enough slack on the other end to allow the drives ??????? to slide out of the bay.? Add 6" onto this measurement. 2.)???? A 50-pin IDC-style "Berg" connector for the RQDXn. 3.)???? A 34-pin IDC-style "Berg" connector for an RX50. 4.)???? One or two 34-pin IDC-style card-edge connectors for RX33's. What to do: 1.)???? Split one end of the ribbon cable as follows. ??????? DON'T separate ALL of the wires individually; keep them paired! ??????? Peel each grouping of conductors back about 4 or 5 inches. ??????? 1,2 ??????? ------------- ??????? 3,4,5 ??????? ------------- ??????? 6 through 10 ??????? ------------- ??????? 11,12,13 ??????? ------------- ??????? 14 through 26 ??????? ------------- ??????? 27,28 ??????? ------------- ??????? 29 through 34 2.)???? Cut conductors 3, 4, 5, 11, 13, and 27. ??????? They won't be used, and there won't be a convenient place ??????? to terminate them on the connector. ? ??????? These wires will need to be insulated at some point. ??????? If you have wide plastic sleeving, then put a section of it ??????? onto the cable.? Heat shrink will NOT work well. ??????? A simple loop of electrical tape should suffice. 3.)???? Conductor 28 needs to be fairly long, since it ??????? lands on the opposite side of the 50-pin connector. ?????? ?Trim about 3 inches off ALL of the OTHER wires. 4.)???? Using a pair of needle-nose pliers, ??????? REMOVE the following contacts from the 50-pin IDC connector: ??????? 7, 9, 19, 20, 23, 27, 31, 43, and 44. ??????? This will prevent certain RQDXn signal lines from ??????? being inadvertently grounded, and will help properly ??????? identify your landing positions for some of the connections. 5.)???? Line up the ribbon cable with the connector, ??????? and check to make sure that conductor 28 is long enough ??????? to reach across the cable, without placing it under any strain. 6.)???? Press the ribbon cable onto the 50-pin IDC connector. ??????? Refer to the chart at the top of this text; You'll see ??????? that they are grouped exactly as they should sit on ??????? the actual connector, with the exception of conductor 28. ??????? Note that SOME groupings start on ODD connector numbers, ??????? and some start on EVEN numbers. 7.)???? If you haven't done so already, refer back to step 2, ??????? and insulate the wires that were cut, to prevent them ??????? from shorting-out against the chassis. 8.)???? Determine where you need your floppy connectors, ??????? and press the connectors onto the 34-pin cable. ??????? Make sure that you observe the position of Pin 1. ??????? I made a "Universal cable" for my BA123. ??????? It has a 34-pin berg, and TWO card-edge connectors ??????? near the end (spaced about 4" apart), and then a THIRD ??????? card-edge connector about 10" down. ??????? This will allow double-stacked RX33's in a single bay, ??????? individual RX33's in separate bays, or a single RX50. 9.)??? ?Test, and enjoy ! ________________________________________________________________________ More new features than ever. Check out the new AIM(R) Mail ! - http://webmail.aim.com

18 years, 4 months

Subject: IBM photostore (was: Re: digital camera capabilities)

by cclist＠sydex.com

> From: Chris Kennedy <chris at mainecoon.com> > CDC and IBM FEs would periodically get into pissing contests over who > was responsible for various faults; recurring ones would end up with a > piece of paper taped to the channel controller that would say something > to the effect of "TP XYZ +X volts -> IBM problem, -Y volts -> CDC > problem". Heh, I was with the CDC STAR-100 installation at LLL/LRL. It was ALWAYS our problem. ;( Sigh, Chuck

18 years, 4 months

digital camera capabilities

by cclist＠sydex.com

From: "Roy J. Tellason" <rtellason at verizon.net> > Speaking of which this brings to mind another old project idea I had that > never went anywhere. That was using a 3" scope tube to "write" to film, > and then after developing, to read it back again. I vaguely recall > "flying spot scanner" being somewhat related to this, I think there was > some equipment out there that'd actually take a 35mm slide. Though I'd > envisioned a roll of film, driven by a stepper motor. Ever hear of the IBM 1360 photostore? http://www.computerhistory.org/virtualvisiblestorage/artifact_frame.ph p?tax_id=02.07.01.00 It was used a verb at Lawrence Livermore--as in "Your file has been photostored." A very unfortunate happening... Cheers, Chuck

18 years, 4 months

Yet another VT-100 emulator

by dave06a＠dunfield.com

>>Not likely - as far as I know there are no standard PC text >>video modes that give 132 columns. > >Long ago I had a 132char driver for the Hercules/TTL mono video card. >I was based on the 720x348 mono graphics mode. > >I also remember the several of the SuperEGA bios that supported the >extended MDA modes: >46h Text 132x25 (8/9x14) >47h Text 132x29 (8/9x12) >48h Text 132x32 (8/9x11) >49h Text 132x44 (8/9x8) As far as I know there are no **STANDARD** PC text video modes that give 132 columns. Yes, at 720 dots, you can do a 5 point wide font for 132 columns on a Herc., but I don't have Hercules (or any MDA) cards in any of the system that I actually use on a regular basis (POLL: How many here are using Herc cards in systems they would want to use as a VT100) - I'm also not sure I could achieve all of the attributes (Can you blink graphics on a Herc? - I suppose you could do it in software, but the only MDA machines I have here are XT class which would make for "interesting effects" :-) I think I also mentioned that I wasn't quite ready to do a bitmapped version of the terminal yet. I agree that it would be nice to do eventually, as I could support double-width/height characters as well... Does anyone know if any of the more modern (ie: VGA) cards support enhanced 132 column text modes? - And is the video addressing basically the same except for 132 words of memory per line instead of 80? And where to find more information? If it could be reliably determined that support was there, and it is compatible with my text windowing code, it would not be difficult to add support for it. Dave Still unsubscribed - Oh Jay ... where are you? -- 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, 4 months

FW: [HeathKit] HERO Robots for sale

by bbooth＠pausd.org

Hello, I have two Hero 1 Robots that would be good for parts. They suffered at the hands of middle school children. Brad

18 years, 4 months

Washing Machine Drives [was: Homebrew Drum Computer (magnetic heads)]

by bnansel＠bigpond.net.au

Thank you very kindly for the offer. I'd be glad to study whatever materials you have, and I'd pay for the postage; if I can't use them I would send them back. Maybe ought to wait until I get some of the logic up and running first, though. So far, however, I'm having zero luck finding washing machine platters or spindles. There are a couple Data General drives on ebay, but I sure can't afford to ship those to Australia! What I need is something like the drive unit from a Data Disc F- series hard drive. IIRC, they had 12" platters, which would be perfect for my machine (plus bitsavers has got the schematics!). I wouldn't turn down 14-inchers, mind you; the smaller size would fit in my car easier. Twenty-five years ago I remember being annoyed that I had to trip over gear like that to get to the *good* stuff at United Products in Seattle. Ah, well, I was a poor university student at the time, and even if I had bought one and hung on to it, my wife would surely have had me committed if I had even proposed dragging such a thing to Australia... -Bobby On Fri Dec 14 2007 Chuck Guzis wrote: > ... > About the only item of the correct size and tolerances that's readily > available today, it seems to me, would be the drum unit out of a > laser printer or copier. I don't know if the OPC layer could be > easily stripped off and replaced with oxide, but it might be worth a > try. > > If you're really serious abou this, I'd be willing to donate a head > from a CDC 808 disk unit--4 bit parallel recording. > > Cheers, > Chuck >

18 years, 4 months

Govliquidation: Rolm 1602 Console

by erik＠baigar.de

There is again one of the unique Consoles, alias Operator Panel for the 1602 vintage computer on govliquidation: http://cgi.govliquidation.com/auction/view?auctionId=1483422&convertTo=USD Maybe there is someone willing to save this from the scrapyard... Best regards and merry x-mas, Erik.

18 years, 4 months

Yet another VT-100 emulator

by classiccmp＠memory-alpha.org.uk

Hi, >>> Not likely - as far as I know there are no standard PC text >>>video modes that give 132 columns. >> >> Long ago I had a 132char driver for the Hercules/TTL mono video >>card. I was based on the 720x348 mono graphics mode. > > As far as I know there are no **STANDARD** PC text video modes >that give 132 columns. Precisely, just what is so difficult about that statement for people on this list to understand!!?? The bottom line is that the **ONLY** ***STANDARD*** text modes supported by EGA and VGA adapters are 40 and 80 column. END OF ARGUMENT. PERIOD. Whilst it is perfectly true that most/all "SuperVGA" cards support one or more 132 column text modes, these modes - along with their mode numbers - are unique to each manufacturer and indeed often differ between chipsets >from the same manufacturer! Great if you want to tie your software to working with only a single brand of chipset/graphics card (which I doubt is what the OP wants), but otherwise utterly useless.... TTFN - Pete.

18 years, 4 months

Yet Another VT-100 Emulator

by dave06a＠dunfield.com

> Any possibility that your VT-100 emulator can be extended > to support 132 character text lines? Most of the programs > that I write are in MACRO-11 and they require 132 character > text lines for the list files which are generated. The > alternative is to use 80 character text lines with wrap > around and that is so messy that it becomes almost useless > by comparison. Not likely - as far as I know there are no standard PC text video modes that give 132 columns. Even in graphical mode, the highest standard resolution supported by VGA is 640x480, which isn't enough for 132 columns. I might be able to do SVGA 800x600 on *most* cards, which could work, but so far I've not done a bit-mapped version (that would be a lot of changes to my emulator). > The other reason is that I use the KEYPAD characters under > RT-11 for both KED and SL:(Single Line Editor). Are you > confident that the <NumLock> keypad key acts as the <GOLD> > key which translates to the 3 character sequence: "<ESC>[P"? > Also, the keypad comma, ".", key on the VT-100 is just above > the <ENTER> keypad key, but does not exist on the PC keypad. > I finally settled on the <Pause> key as a substitute since > there never seemed to be any use other for <Pause>. What > does your VT-100 emulator substitute for the keypad comma, > ",", key? The original terminal I announced was "close" on the keypad, but did not support use of the NumLock, '/' or ENTER keys. I've just posted an updated version which is "really close", and is limited only by the physical keypad difference. In this version I map (on the keypad in application mode): NumLock = PF1, '/' = PF2, '*'=PF3, '-' = PF4 0-9 = 0-9 '.' = '.' ENTER = ENTER '+' = ',' PgDn = '-' I chose this layout because '+' takes up both '-' and ',' slots, and PgDn is the closest additional key I could get to either one of those - It's at the same latitude as '-', but to the left of '7' instead of to the right of '9'. The good news is that I've added a "Keyboard mapping" configuration function which will allow you to assign the individual Normal, SHIFT and CTRL functions of *ANY* key on the keyboard, so you aren't stuck with my choices. You can also assign multiple PC keys to the same VT-100 function if you like. I've also got 30 programmable function keys using PC F1-10 ShiftF1-10 and CtrlF1-10 which you can define to any strings you like. These too can be remapped to appear on other keys. > And finally, On the VT-100 keyboard, the SCROLL/NOSCROLL key > is at the bottom left hand corner of the keyboard. While the > standard 105 keyboard from a PC can't exactly correspond to > the VT-100, the <Left Ctrl> key can act in that manner and the > <Caps Lock> key then becomes the <Ctrl> key on the VT-100. Is > your VT-100 emulator able to manage this aspect as well? I hadn't implemented NoScroll (never use it, I'm so used to entering CTRL-S and CTRL-Q directly on various systems)... I really didn't want to mess with the CTRL keys since I'm very used to where they are located on the PC, so I've added NoScroll to the PC "Scroll Lock" key. As noted above, you can now assign the behaviour of all keys, so you can easily create exactly the layout you requested. My keyboard handler differentiates between Left and Right Ctrl, Alt, Shift and "windows" keys, so you can map these individually any way you like. I default "Caps Lock" to "Caps Lock", but you can move that to another key and make it the CTRL key if you wish (my keyboard remapper supports assigning SHIFT and CTRL keys as well - just be sure to assign them in ALL modes - otherwise they move around as you move between Normal, SHIFT and CTRL modes, which can be a bit confusing... Another thing I've added in this most recent version is that I came up with technique when using a VGA card to not only load a custom font which gives you all the VT-100 graphic characters, but also to enable all of the VT-100 attributes (Bold, Underline, Blink and Reverse) in any and all combinations. I forgot to mention last time - I'm interested in improving the emulator, so I'm happy to make corrections and additions (within reason) - just let me know what you you would like to see. Dave NOTE: I am currently unscribed from the list - I've been trying for the past week to get resubscribed, however so far no joy ... The only way I have to read it is via the web site which is rather painfull, and somewhat delayed - so reponses will be slow in coming. I'm hoping this will go through since I've seen other messages which appear to be from non-subscribers. -- 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, 4 months

Yet another VT-100 emulator

by cclist＠sydex.com

From: "Ensor" <classiccmp at memory-alpha.org.uk> > The OP needs modes which work on ALL adapters, not non-standard modes > which work on a small number of Mickey Mouse cards which noone uses.... With all due respect, I think the observations on the part of the other posters including myself were valid. What the OP probably meant to say was: "Does anyone know of a video text mode supported by a standard IBM VGA/PGC/XGA/EGA card real-mode 16-bit BIOS that supports 132 colums?" That "BIOS" keyword is very important, given that few operating systems actually use it to do anything useful nowadays. In point of fact, there has been little "standard" since third-party vendors began sourcing their versions of the VGA card. And IBM by that time was far from the majority presence in the marketplace. Cheers, Chuck

18 years, 4 months

cctalk Digest, Vol 52, Issue 38

by cclist＠sydex.com

On 18 Dec 2007 at 20:29, cctalk-request at classiccmp.org wrote: > Seocndly, if you fiddle with the video heads themselves, be warned they > are delicate. They are brittle ferrite cors, the windings are thin and > brought out to little BCPs stuck in postiion. If you break the wires > you'll not be able to fix them.If the PCB comes uncluged, it'll break the > wires. And if the head tip bangs into anything it will shatter. That is > the bitter voice of experience from the time I rebuilt the head assembly > in a portable rell-to-reel VTR (sorry it's off-topic, so I'll stop there). I was going to suggest a head from a Telcan video recorder as being more suitable, but I doubt that there are many of those around. Maybe a head from one of the cheap floppytape QIC drives might also do the trick. Cheers, Chuck

18 years, 4 months

Shift Registers as Delay Lines (was Delay lines in TV sets)

by ajp166＠bellatlantic.net

> >Subject: Re: Shift Registers as Delay Lines (was Delay lines in TV sets) > From: Dave McGuire <mcguire at neurotica.com> > Date: Tue, 18 Dec 2007 11:18:57 -0500 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > >On Dec 18, 2007, at 5:03 AM, Ethan Dicks wrote: >>> MOS shift registers of lengths greater than a few bits are very late >>> 60s (after 67 or so). By early 70s parts 1024 long ere not uncommon. >> >> I think I have a couple of old SAD1024 MOS shift registers from when I >> was collecting deeply discounted items from the local Radio Shack >> "Manager's Table" as a kid. >> >> I had thought one day to make the audio echo/delay circuit I think I >> saw in an old Forrest Mims circuit book, but a solid-state acoustic >> delay line emulator sounds like a much cooler place to put them. Consider that there are only 1024 buket in that brigade and if your storing bits thats about it or less. Maybe even Nyquist less. Allison > > I remember that project, in the "Engineer's Notebook" book. I >wanted to build it too, but I never quite managed to amass all the >parts. (back then, of course) > > -Dave > >-- >Dave McGuire >Port Charlotte, FL >Farewell Ophelia, 9/22/1991 - 7/25/2007 > >

18 years, 4 months

Docs/Software/Info for Virtual Microsystems 8086 Dec Pro board?

by derschjo＠msu.edu

Inherited a Dec Professional 350 with a card labeled as a "Virtual Microsystems Inc. Pro Bd." installed in it. It has an 8086 chip on it, and from the (very) limited information I've found on it I'm guessing it's a card that affords the Dec Pro some amount of IBM PC compatibility. Anyone know anything about this thing? Anyone have any software for it? :) Thanks, Josh

18 years, 4 months

have you seen www.fortran.com?

by cclist＠sydex.com

> From: Chris M <chrism3667 at yahoo.com> > I realize that old doggies die hard, but who except > for the scientific/engineering crowd would want to > create new apps, and for what reason? I imagine there > could be some good reasons to port old (iron?) code to > peecees, but gcc can compile FORTRAN already (albeit > only F77). Dear me, where do I start? For me, FORTRAN is hugely efficient. It's one of the few languages where folks on the ANSI working group actually spend their careers writing automatic optimizers for the language and will raise a stink where a particular construct does not lend itself to efficient or safe optimization. Some of the optimizations performed by the top- end compilers are amazing to the point of one smacking one's forehead and saying, "Damn, that's clever!" At least at one time, it was true that FORTRAN was one of the most portable language, executing on the widest range of systems. I think one of the advertised attractions of the PDP 8/L that contributed to its success was that it could speak FORTRAN. Some of the earliest cross-assemblers that I ever saw were written in FORTRAN, that would pretty much run on any system that supported the language. This was back in the days when USASCII was a character set used on the minority of computer systems; not all were 2's complement (or even binary). Yet you could write a cross assembler (and probably a compiler) that would run on anything. I know of operating systems written in FORTRAN, as well as great hunks of several compilers. I even wrote my early data conversion routines on CP/M using FORTRAN for most of the code. FORTRAN used to have the only really reliable math routines. It's not a bad language to have under your belt. Does ACM CALGO still accept FORTRAN as a permissible source language? Cheers, Chuck

18 years, 4 months

Corvus drivers for Xerox 820/Bigboard

by snhirsch＠gmail.com

I'm looking for the drivers that will let my Bigboard speak to a Corvus flat-cable drive. I have a couple of the interface boxes that go between the parallel port and the drive unit, but have never been able to locate the required software nor any installation docs. If anyone in Classic Computer-land can help, I'd really appreciate it. Steve --

18 years, 4 months

Read and write film - was digital camera capabilities

by lee＠geekdot.com

> That was using a 3" scope tube to "write" to film, and then after > developing, to read it back again. I vaguely recall "flying spot > scanner" being somewhat related to this, I think there was some > equipment out there that'd actually take a 35mm slide. Though I'd > envisioned a roll of film, driven by a stepper motor. It sounds like you were trying to reinvent the telecine machine. Monochrome versions can indeed both read and write film using the same mechanism and it tends to be claw drive rather than a stepper motor. Lee.

18 years, 4 months

Listing paper FTGH (Yorks, UK)

by listmailgoeshere＠gmail.com

Hi list, I have 7 2000-sheet boxes of tractor-feed plain 11x14.5" listing paper which I'd like to give away as I need the space back. Located in West Yorkshire, UK. Sorry, it isn't greenbar ;) There are also 3 boxes of A4-ish size (11x9.5" I think they are). Free, but you'll have to collect. I'd ship if you're desperate, but it won't be cheap as they're heavy. Please drop me a mail if you're interested - thanks. Ed.

18 years, 4 months

Jump to page:

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb