test-drb June 2007

test-drb@ccmp.vtda.org

224 participants
486 discussions

Telephony switches - is there anyone out there collecting these?

by classiccmp＠memory-alpha.org.uk

Hi, > I have a couple of the old GPO [1] Modem 2B units.... Brings back memories....the 2B was my first modem back in '85. Lots of fun, but not as convenient as one which responds to Hayes "AT" commands. I may still have some documentation somewhere if it's any use to you? TTFN - Pete.

17 years, 5 months

Tandy 2000 hack

by chrism3667＠yahoo.com

any thoughts? And although he claimed the 2000 never generated a NMI, won't a parity error always do this? Irrelevant maybe cuz that's a catastrophic fault thing, not something typically encountered... Maybe he provided more details, but I'm tired... > > I was working on a mod, never completed, for the T2K > > that would make it > > after the O/S was loaded, 100% PC-compatible. > > Required 1 hardware chip, > > and a customized IO.SYS. Whereupon any DOS > > application would run on the T2K, > > even stuff doing serial-port manipulation, direct > > video-memory writes, DMA, > > etc. The one-chip mod was a PAL that monitored the address lines from the CPU, when It saw an I/O instruction in 'low' address-space, it generated an NMI (not used at all by the T2K), then the software service routine for NMI unwound the stack to find the offending I/O instruction, and re-mapped the "PC" functionality to the T2K hardware. Coupled with a timer-tick 'refresh' routine that copied data from "PC video memory" to the T2K video memory (remapping attributes, etc. as required.) The chip actually had 2 modes of operation -- NMI active, as described above, and 'NMI inactive', where it pretty much did nothing -- except listen for the 'magic words' that made it go active, that is. :) This enable/disable mode switching was necessary, to allow "T2K DOS" internals (and/or the 'sofware service routine) to access the T2K hardware directly. ____________________________________________________________________________________ Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Yahoo! Games. http://sims.yahoo.com/

17 years, 5 months

Drum vs. Core

by ajp166＠bellatlantic.net

> >Subject: Re: Drum vs. Core > From: "Chuck Guzis" <cclist at sydex.com> > Date: Fri, 29 Jun 2007 13:49:22 -0700 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >While the main store on the IBM 650, didn't most of the installed >base (eventually) also have 50 words of core as sort of a >"scratchpad" memory? > >Cheers, >Chuck This was common. The problem with rotating memory, mercury delay, magnostrictive delay and even shift registers is they are not random access they are sequential access They all have a fixed delay and you wait for what you want to "come around". Programmers had to program around that if speed was required. Allison

17 years, 5 months

Fw: more...

by jrkeys＠concentric.net

----- Original Message ----- From: "Tim Deaton" <timdeaton at yahoo.com> To: "Keys" <jrkeys at concentric.net>; "Al Kossow" <aek at bitsavers.org> Sent: Thursday, June 28, 2007 7:36 PM Subject: Re: more... > John, > > Send me a number were I can call U after 9PM or on > weekends when the cell phone (NEXTEL) is 'free'. > > I am in Indiana - Eastern Time Zone. We can discuss. > > You can call me free any time if you have Sprint or > Nextel. > > My incoming calls are all free. > > Tim Deatom > 317-716-8807 > > > > ____________________________________________________________________________________ > Park yourself in front of a world of choices in alternative vehicles. > Visit the Yahoo! Auto Green Center. > http://autos.yahoo.com/green_center/ He has tons of doc's, 15 Televideo terminals, 100+ monitors, 100+ printers, 100's of new parts, tons of software (OS's, WP's and no games), many more things than I can list. If you live in his area please try and rescue this stuff, it's all free to good homes. I wish I could get some of the tons of documentation and service manuals that he has from his old business. He's in Indiana. Thanks for reading, John Keys

17 years, 5 months

C= LED watch on epay...

by Watzman＠neo.rr.com

I think someone will be disappointed; it looks like an LCD watch, not an LED watch.

17 years, 5 months

HP-IL sighting!

by mcguire＠neurotica.com

HP-IL interfaces turn up in the oddest places. This sound level meter on eBay looks to have an HP-IL interface, shown in the pics: http://shorterlink.org/2335 -Dave -- Dave McGuire Port Charlotte, FL

17 years, 5 months

LARGE IN RESCUE NEEDED Was Fw: more...

by jrkeys＠concentric.net

Sorry for double post but wanted to clear up message subject ----- Original Message ----- From: "Keys" <jrkeys at concentric.net> To: "cctalk at classiccmp" <cctalk at classiccmp.org> Sent: Saturday, June 30, 2007 10:27 AM Subject: Fw: more... > > ----- Original Message ----- > From: "Tim Deaton" <timdeaton at yahoo.com> > To: "Keys" <jrkeys at concentric.net>; "Al Kossow" <aek at bitsavers.org> > Sent: Thursday, June 28, 2007 7:36 PM > Subject: Re: more... > > >> John, >> >> Send me a number were I can call U after 9PM or on >> weekends when the cell phone (NEXTEL) is 'free'. >> >> I am in Indiana - Eastern Time Zone. We can discuss. >> >> You can call me free any time if you have Sprint or >> Nextel. >> >> My incoming calls are all free. >> >> Tim Deatom >> 317-716-8807 >> >> >> >> ____________________________________________________________________________________ >> Park yourself in front of a world of choices in alternative vehicles. >> Visit the Yahoo! Auto Green Center. >> http://autos.yahoo.com/green_center/ > > He has tons of doc's, 15 Televideo terminals, 100+ monitors, 100+ > printers, 100's of new parts, tons of software (OS's, WP's and no games), > many more things than I can list. If you live in his area please try and > rescue this stuff, it's all free to good homes. I wish I could get some of > the tons of documentation and service manuals that he has from his old > business. He's in Indiana. > > Thanks for reading, > John Keys

17 years, 5 months

Drum vs. Core

by ajp166＠bellatlantic.net

> >Subject: Re: Drum vs. Core > From: Roger Holmes <roger.holmes at microspot.co.uk> > Date: Fri, 29 Jun 2007 19:27:10 +0100 > To: cctalk at classiccmp.org > > >> >> Core was available by 1952, most of the big machines after this >> date (on this side >> of the pond at least) were core based. The IBM 650 was actually one >> of the smaller >> machines, at least inasmuch as IBM was already making much larger >> machines >> (the 700 series). > >Wasn't core memory very expensive in the beginning? Yes and new. It was also temperature sensitive as the required ferrites and circuits were not fully developed. > It had to be hand >assembled, at least in the early days. I think there was a more >gradual take up than you suggest. Of course the more expensive >machines which used it first saw a huge speed increase over drum main >memory. When I was at university (71-74), the college's mainframe >still used a drum from program overlays (probably really the virtual >memory backing storage, but possibly just dumping and restoring the >whole program between time slices. The machine was no slouch, it was >serving about a hundred terminals and running a couple of batch >streams as well (Maximop and George 2). Actually core appeared in two places in machines. TX2 was an exellent example where core was used as main store and also there was a far smaller "fast store" using core that was really for use as registers. >Mid 1970s I remember seeing a small plastic pot about the size of a >35mm film canister, which was full of about 100,000 unstrung cores, >they were tiny! They were used in the Marconi-Elliott 920ATC computer >and also in the early Cruise missiles and some torpedoes. Ever >wondered why a British submarine used a WW2 type torpedo to sink the >big Argentinian Cruiser? My theory is that they were too worried >about the modern torpedoes coming back and blowing themselves up, so >they used one they trusted to go where it was pointed. Hopefully 25 >years on, they've sorted out the terrible guidance system. Not >related, but apparently the programmers were in a quandary as to what >the program should do after it had issued the order to detonate. Like >the old TV series 'Waiting for God'. > >The first machine which ICT introduced with core memory was in 1962, >though physically large, the 1300 was a medium power machine, seen >more as a versatile tabulator for accounts rather than scientific >work, though it had a structural frame analysis package and even >PERT, though I suppose that is just up market accounting in a way. >Customers did all sorts of other work on it too, helping to design >'planes and even playing music on the built in speaker. There's a >wonderful program called Ghost, only a half a dozen instructions, >which uses the variable length of the multiply instruction to make a >ghostly sound on the speaker. Its a good test of the CPU too, and can >be keyed in through the control panel if need be in a minute or so. >Also has drums - each one 12000 words x 48 bits run by a 3/4 >horsepower motor and occupying 2ft x 2ft x 5 ft. Compared to the 8GB >SDHC card for my 12MP camera which is about an inch by an inch by a >sixteenth and stores 100,000 times as much in about 1 / 500,000 times >the volume. And the core store is one sixth the capacity of the drum >in a greater volume. I remember the fixed head (head per track) word parallel swapping drums on PDP-10s. Those were 128kW but fairly small and motors were on a 1/4hp scale. That and the PDP-8 32k fixed head platter (RS08) that were often used for swapping as they were fast using multiple fixed heads and working as word parallel. Around the time of the Altair you could buy surplus drums most fixed head that were fairly small physically and techically easy to interface though the amount of repeated circuits were large in quanitity. Allison

17 years, 5 months

Billy Pettit real disappointment

by RodSmallwood＠mail.ediconsulting.co.uk

Here's my five cents worth. I see computers and computing as different things. We discuss a lot about old hardware and to some extent and rather less about old software. What's in short supply is how the hard/soft combinations were used practically. "Are there any interesting old applications out there?" As to the on/off topic issue. I don't see any problem with comparing and contrasting the old with the current. If one topic arises out of another and is of interest to others on the list and gets a response so be it. If there is no response then the silent majority have voted. I am concerned that difference between moderation and censorship could, at some time in the future, (present situation excepted) become less distinct. Rod Smallwood -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Jay West Sent: 28 June 2007 13:58 To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Billy Pettit real disappointment Billy wrote... >> Come on people: there were computers long before there were >> microcomputers. I seem to remember a recent post complaining that this list was nothing but minicomputer and big-iron talk, no microcomputer discussion. Apparently that was wrong, as now there is a complaint it's just micro talk? ;) Jay `

17 years, 5 months

LISA

by pdp11_70＠retrobbs.org

So... I've got *the* lisa emulator set up and can (at last) play with that computer that I wanted when I was 12 (I still remember seeing one at Computer Pro and being amazed!) So, does anyone know what happened to that 90,000+ lines of (Pascal) Source Code for LOS? It would sure been neet to be able to look at it. It would be even more need to write a TCP/IP stack for the thing, and some how hook up a scsi asanti ethernet adapter to a real Lisa and put it on the web without using Macworks. But as I don't have any of the real equipment... I guess that's just a pipe dream. Wow. mark -- "Well, Steve, I think there's more than one way of looking at it. I think it's more like we both had this rich neighbour named Xerox and I broke into his house to steal the TV set and found out that you had already stolen it." -Bill Gates to Steve Jobs On Windows --

17 years, 5 months

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test-drb June 2007