test-drb January 2005

test-drb@ccmp.vtda.org

254 participants
551 discussions

by RCini＠congressfinancial.com

OK, this might sound like a stupid question, but being somewhat ignorant of RTL logic in comparison to TTL and other designs, what, if anything, can be substituted for RTL logic chips? For example, if I wanted to build one of Don's devices and I wasn't concerned with using "vintage" chips, could I do it "plug-and-play" using current TTL? Rich -----Original Message----- From: cctalk-bounces(a)classiccmp.org [mailto:cctalk-bounces@classiccmp.org]On Behalf Of Michael Holley Sent: Friday, January 07, 2005 12:08 AM To: cctalk(a)classiccmp.org Subject: RTL Logic I have acquired some Don Lancaster designs that use RTL logic and I am looking for spare parts. The MC789 hex inverter is used in all of them and I have 2 chips. Does anyone have a reasonable source for the MC789, I can get all I want for $20 a chip. I also have 2 MC799 buffers that are use in the Microlab. I have found two each of these (MC725, MC778, MC785, MC792, MC853, MC855) that I will part with. SWTPC Digital Logic Microlab http://www.swtpc.com/mholley/PopularElectronics/Apr1970/PE_Apr1970.htm Early SWTPC keyboard http://www.swtpc.com/mholley/PopularElectronics/Apr1974/PE_Apr1974.htm I think that Don Lancaster's TIC TAC TOE machine from 1971 is a very clever design. It uses 5 ICs and 60 diodes to play the game. I may build one. http://www.swtpc.com/mholley/RadioElectronics/Dec1971/RE_Dec1971.htm Michael Holley www.swtpc.com/mholley

19 years, 9 months

RTL Logic

by melamy＠earthlink.net

dirt has been known to be found in most places in the world... doing a wired-or and wired-and depends on reading IC specifications for specific chips. It is what design engineers do... -----Original Message----- From: Tom Jennings <tomj(a)wps.com> It varies from chip to chip and family to family. Wire OR/etc was common as dirt.

19 years, 9 months

more nice hp stuff on ebay

by jwest＠classiccmp.org

It's unusual to see one on Ebay... an HP 7210A plotter in what appears to be awesome condition. Same seller has a 9866A printer in very nice shape too. I don't know why I'm so intrigued by the 7210, I wouldn't use a plotter for anything I do, but it's soooo "period" :) Jay West

19 years, 9 months

Wanted: Contact info for Buyer at Gov. Auctions

by ICS＠Core.com

Hi everyone, Anyone know of a guy that buys from NASA, goverment Auctions in the Maryland area? I'm trying to learn of what happened to some hard drives that he bought. Thanks, George

19 years, 10 months

RTL Logic

by dwight.elvey＠amd.com

Hi Actually regular TTL can take momentary shorts on the outputs to ground. When desperate in trouble shooting, I've been know to ground an output. It is not such a good idea on S parts though. Dwight >From: "Tom Jennings" <tomj(a)wps.com> > >On Fri, 7 Jan 2005, Steve Thatcher wrote: > >> I did wired-and with open collector TTL gates all the time... common as dirt! LOL > >D'OH!! > >R U sure that wasn't wired-NOR? > >(ducks from thrown tools) >

19 years, 10 months

RTL Logic

by melamy＠earthlink.net

that was a function of input, not output - I was using 7409s... :) -----Original Message----- From: Tom Jennings <tomj(a)wps.com> Sent: Jan 7, 2005 5:52 PM To: Steve Thatcher <melamy(a)earthlink.net>, "General Discussion: On-Topic and Off-Topic Posts" <cctalk(a)classiccmp.org> Subject: RE: RTL Logic On Fri, 7 Jan 2005, Steve Thatcher wrote: > I did wired-and with open collector TTL gates all the time... common as dirt! LOL D'OH!! R U sure that wasn't wired-NOR? (ducks from thrown tools)

19 years, 10 months

RTL Logic

by dwight.elvey＠amd.com

Oops! I forgot one thing. You can put several RTL outputs in parallel as a wired AND. You can't do that with the general CMOS or TTL. You'd need to look out for this. Does anyone have a source for DTL parts. There are a could I've been looking for. Dwight >From: "Cini, Richard" <RCini(a)congressfinancial.com> > >OK, this might sound like a stupid question, but being somewhat ignorant of >RTL logic in comparison to TTL and other designs, what, if anything, can be >substituted for RTL logic chips? > >For example, if I wanted to build one of Don's devices and I wasn't >concerned with using "vintage" chips, could I do it "plug-and-play" using >current TTL? > >Rich > >-----Original Message----- >From: cctalk-bounces(a)classiccmp.org >[mailto:cctalk-bounces@classiccmp.org]On Behalf Of Michael Holley >Sent: Friday, January 07, 2005 12:08 AM >To: cctalk(a)classiccmp.org >Subject: RTL Logic > > >I have acquired some Don Lancaster designs that use RTL logic and I am >looking for spare parts. The MC789 hex inverter is used in all of them and I >have 2 chips. Does anyone have a reasonable source for the MC789, I can get >all I want for $20 a chip. > >I also have 2 MC799 buffers that are use in the Microlab. I have found two >each of these (MC725, MC778, MC785, MC792, MC853, MC855) that I will part >with. > >SWTPC Digital Logic Microlab >http://www.swtpc.com/mholley/PopularElectronics/Apr1970/PE_Apr1970.htm >Early SWTPC keyboard >http://www.swtpc.com/mholley/PopularElectronics/Apr1974/PE_Apr1974.htm > >I think that Don Lancaster's TIC TAC TOE machine from 1971 is a very clever >design. It uses 5 ICs and 60 diodes to play the game. I may build one. >http://www.swtpc.com/mholley/RadioElectronics/Dec1971/RE_Dec1971.htm > >Michael Holley >www.swtpc.com/mholley > >

19 years, 10 months

Importing binary files without removable storage nor non-bundled software (was: TKermitFTP

by melamy＠earthlink.net

the only reason Microsoft would not add binary transfer capability as an integral part of early DOS is that the people that needed it were in a small minority. It made no business sense to include features that they believed that most people really didn't need. Later in DOS, they did include a basic file transfer capability over a cable. Probably more out of pressure because people used products like LapLink and complained that they had to buy something instead of having it built in. It was designed to transfer files (and filenames) like a real software package like Telix would do when running zmodem protocol. A programmer can write any software, but they still are employed by the company that hired them and the product requirements. If Microsoft had put "everything" into early DOS, then companies like Norton, Traveling Software, etc would have not even been started. I have long held the concept that Microsoft has always been a 90% solution and the remaining 10% are the opportunities for outside companies. best regards, Steve Thatcher

19 years, 10 months

RTL Logic

by melamy＠earthlink.net

I did wired-and with open collector TTL gates all the time... common as dirt! LOL -----Original Message----- From: Tom Jennings <tomj(a)wps.com> Sent: Jan 7, 2005 3:59 PM To: Steve Thatcher <melamy(a)earthlink.net>, "General Discussion: On-Topic and Off-Topic Posts" <cctalk(a)classiccmp.org> Subject: RE: RTL Logic On Fri, 7 Jan 2005, Steve Thatcher wrote: > dirt has been known to be found in most places in the world... > > doing a wired-or and wired-and depends on reading IC specifications for specific chips. It is what design engineers do... Sorry for being so obtuse! Phrase meant: "wire OR/etc was very common in RTL". I tried wired-OR once in TTL, didn't like the results :-) > > -----Original Message----- > From: Tom Jennings <tomj(a)wps.com> > > It varies from chip to chip and family to family. Wire OR/etc was > common as dirt. >

19 years, 10 months

Can anyone identify this IBM magnetic tape cartridge?&In-Reply-To=a06010204bbdf7cfbe966@[192.168.1.1

by SAEICHNER＠rainbow-media.com

I'm responding to a very old posting that I came upon quite accidentally. The tape in question is a "Precon" tape used by the IBM Magnetic Tape Selectric Composer system introducted by IBM in 67. I worked for IBM at the time and subsequently used a lot of this equipment in my graphic arts/typesetting business. The tape was used to "pre-condition" the IBM MT/SC based on what you were trying to do, i.e., set straight text type, set tabular type, set type using an outline format, or set horizontal rules. It was sort of a "download" of code to get the machine set up for what you were about to do because all of the code could not be resident in the MT/SC at the same time. The Precon 256 was used for straight columnar text type; the Precon 260 was used for text in outline format (1.(a).1 etc), Precon 261 was used for tabular work--columns and Precon 259 was used to create automatic horizontal rules specifically for use in classified ads. Precon 263 was a diagnostic Precon. There were many other Special Feature Precons such as 340, 341, 342 and 343 for automatic letter writing functions and automatic paragraph selection, etc. Interesting stuff. Good equipment--I liked using it very much. P.S.--The tape has no value--other than memories. At the time the tape cost about 40 bucks--the MT/SC cost about $35,000! Steve Eichner Manager, Business Systems Standards & Assurance Rainbow Information Systems 516-803-5102

19 years, 10 months

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test-drb January 2005