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101090 discussions

Ink stamp on 1970s IC's.

by ddameron＠earthlink.net

Hi all, I have seen several plastic DIP IC's from the 1970's have a white ink stamp on them that say something like "ETC 4" on them. (Your number may vary) Most are Intel RAM's, but some are Signetics or National TTL. Before I have seen them on chips on boards, but have now bought a bunch of IC's new in tubes which also have this stamp. Has anyone else seen this and know what it means? -Dave

27 years, 8 months

Altair FP Schematic?

by rcini＠msn.com

Hello, all: Does anyone have a schematic for the Altair front panel? In my document collection, I have the CPU, power supply, clock, and RAM schematics, but not the FP schematic. Thanks. [ Rich Cini/WUGNET [ ClubWin!/CW7 [ MCP Windows 95/Windows Networking [ Collector of "classic" computers [ http://highgate.comm.sfu.ca/~rcini/classiccmp/ [ http://highgate.comm.sfu.ca/~rcini/pdp11/ <================ reply separator =================>

27 years, 8 months

Zorba the Geek

by sinasohn＠ricochet.net

27 years, 8 months

Reiability of wrong media (was: is out of 5-1/4" diskettes

by pete＠dunnington.u-net.com

On Jan 21, 16:58, Sam Ismail wrote: > Subject: Re: Reiability of wrong media (was: is out of 5-1/4" diskettes > On Fri, 22 Jan 1999, Pete Turnbull wrote: > > > "OK, so that's a flippy", I said to myself. A little later, I re-read the > > catalogue -- and got a different listing! I had inadvertantly catalogued > > side two, with the disk right-side-up -- and realised that the tracks must > > not line up, so side two had two sets of data, going in opposite rotations, > > with the tracks interleaved! > > This can't be possible! Otherwise, why didn't someone exploit this to > make 4-sided diskettes?? It was an 80-track drive, but the disk was formatted to 40 tracks originally -- there just happened to be two sets of 40 on one of the sides. The second set was probably recorded on a double-stepped 80-track drive, so the track width was only half as wide as a real 40-track would have written, and becuse of the offset between upper and lower heads, just happened to fall in the right place. It would be an awfully complicated way to get 80 tracks out of an 80 track drive :-) -- Pete Peter Turnbull Dept. of Computer Science University of York

27 years, 8 months

eBay Finds (was: Ebay Posts was...)

by sinasohn＠ricochet.net

At 02:41 PM 1/21/99 -0800, you wrote: >> For $5 and shipping, I got (on eBay!) a Sharp PC-5000 laptop. No biggie >Are you sure this isn't just a re-branded Gavilan? Sounds an awful lot >alike. Very sure. Though I suppose the Gavilan could have copied the Sharp's design. 8^) --------------------------------------------------------------------- O- Uncle Roger "There is pleasure pure in being mad roger(a)sinasohn.com that none but madmen know." Roger Louis Sinasohn & Associates San Francisco, California http://www.sinasohn.com/

27 years, 8 months

Kaypros and Osbornes

by sinasohn＠ricochet.net

At 03:05 PM 1/21/99 -0500, you wrote: >I might be willing to unload mine. When I hear one went for $400 on E-Bay. I've not heard of a Zorba going for $400 on eBay. The only one I've ever seen on there went for a little over $125. It was the weekend around 11/9/1997 and I was on a weekend get-away with my GF when it closed. I had also blown a significant bit of cash on the weekend, so I couldn't just bid higher. --------------------------------------------------------------------- O- Uncle Roger "There is pleasure pure in being mad roger(a)sinasohn.com that none but madmen know." Roger Louis Sinasohn & Associates San Francisco, California http://www.sinasohn.com/

27 years, 8 months

Finished Posting MOS Hardware Guide

by rcini＠msn.com

Hello, all: Tonight, I finished posting the MOS Technologies Hardware Guide. It appears to be a complete guide to designing and using MOS microprocessor and peripheral products. [ Rich Cini/WUGNET [ ClubWin!/CW7 [ MCP Windows 95/Windows Networking [ Collector of "classic" computers [ http://highgate.comm.sfu.ca/~rcini/classiccmp/ [ http://highgate.comm.sfu.ca/~rcini/pdp11/ <================ reply separator =================>

27 years, 8 months

2002 (was:: Looking for pointers to old Control Data software)

by Jgzabol＠aol.com

Hello Hans, you are certainly welcome to it - after all its only bits and not a single atom, so it can be copied easily. However, there is no documentation apart from source code comments - it's a (hopefully) portable C program plus some ASCII data files, so it should run on anything that has a C-compiler. Since your address makes me believe that you are affiliated with Siemens Munich, and since I live in Munich too, maybe we just get together and discuss this ? I will send you my coordinates in private email. The simulator maps core and drum to RAM arrays, papertape input and output to File I/O, and the console to keyboard/screen. It would be neat to interface to a real S2002 console - there are at least two in Munich, one at the Siemens museum and one at the Deutsche Museum; maybe that would be a fun project to try one of these to agree to that proposal ????? The compiler I have is in fact the Alcor Triplex Main S2002, the result of a thesis (not mine) done at Mainz University in 1968, extending Algol by the data type TRIPLEX which is an interval representation of a floating-point number: [lower-bound, standard-f.p., upper-bound] Any operation on triplex numbers will produce the min/max values resulting >from possible roundoff, so that the error propagation of roundoff may be studied. This is theoretically nice, but in practice you can invert a 10x10 matrix only if you are lucky and it is conditioned extremely well, otherwise some pivot interval will include 0 resulting in a divide error. In those days there were fears that one could not do any calculation involving millions of f.p. operations because of roundoff - that turned out to be really academic. John G. Zabolitzky

27 years, 8 months

FS: Add-in 2 Serial/2 Parallel cards

by rhblake＠bigfoot.com

I have a bunch of DFI serial/parallel adapters for sale for $7.50 each ($20 for 3) plus shipping, with docs. They have the Winbond chipset that includes 16550 UARTS and gives you 2 serial and 2 parallel ports. Better than an A/B switch if you run more than one printer, or great if you have a parllel port device like scanner. No more worry about conflicts. Works great under DOS through Win98. I have one in everyone of my 8 bit and 16 bit machines and one in my EISA server. This one is excess and needs a good home Totally setable to whatever you need. The docs (if you want to look at them) are available in PDF format at ftp://ftp.dfiusa.com/multi_io_cards/DIO222/d220830.pdf Full spcifications are shown. Includes 2 9 pin serial and 2 25 pinprinter ports, one of each on the card and one of each on an addtional slot filler, but you can move these to case openings if you desire. Shipping is minmal, probably $3.25 for a couple of them. Also have a couple Intel (and other brands) 14,400 baud internal faxmodems. Windows 95 and 98 see them fine and they work great with Win 3.1 and DOS too. All clean and in great shape. $6 each or 3 for $15 plus shipping. Again, a light item. These work great for someone with an occasional need for internet, send/recv faxes or to use free email or call BBS systems.. These items are for sale to US and APO/FPO addresses only. Shipping to other countries is not cost effective and is a real pain in many cases. I use USPS parcel post, insured unless priority is real close to the same price. Drop me a direct email if interested. Payment by money order only. Ships the same or next day as payment is recieved. These are items I have picked up for other projects and ended up with way too many, these are not connected with a business and are personal sales.

27 years, 8 months

Disasters and Recovery

by jfoust＠threedee.com

At 09:31 AM 1/20/99 -0500, William Donzelli wrote: >> > What makes some of today's technology fragile is simply the density, or >> > equivalenty, the lack of redundancy in a given area. > >Take a look at the specification for how CDs are formatted. You may be >suprised to find out that a good chunck (more than just a few percent) is >dedicated to error correction! That is why you do not hear all of the >scratches in poorly handled CDs. Well, hearing an error on an audio CD might be difficult. If cost is no object, you could have the data pressed to a mastered CD, as opposed to burning a CD-R at home. The "real" aluminum mastering process entails a "glass master" that might last longer than the aluminum foil version. Are there any CD mastering plants that give you an option of true gold foil, to avoid oxidation? - John

27 years, 8 months

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