test-drb

test-drb@ccmp.vtda.org

101090 discussions

by dgriffi＠cs.csubak.edu

I've scanned and OCRed the Radio Shack pt210 printing terminal users manual and service manual. If someone wants them right now, please email me. I'm waiting for Howard Harte to grab them from my super-secret website to put it in his archive of manuals. -- David Griffith dgriffi at cs.csubak.edu

18 years, 5 months

*updating* 8088's

by ajp166＠bellatlantic.net

> >Subject: Re: *updating* 8088's > From: "Chuck Guzis" <cclist at sydex.com> > Date: Tue, 20 Nov 2007 16:38:01 -0800 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On 20 Nov 2007 at 16:27, Fred Cisin wrote: > >> Wasn't the PS/2 30 an 8086? (can't remember for sure) > >Initially. A later version used the 286. The model 25 was, as far >as I'm aware, always an 8086. The model25 was 8088 powered and I think a few others of that series. Allison >Cheers, >Chuck > >

18 years, 5 months

Sun 3/4 updates

by compoobah＠valleyimplants.com

Al was right about the Sun 3/200 - it was the PROM - more specifically the complete absence of the PROM - that left the diag lights on all the time. That board's been shelved for a while. The 4300 is up though - it was the NVRAM (someone had put it in backwards at some point during the board's lifetime). Fortunately I had another 4300 board (suffering from the "all lights on" plague) that I grabbed the NVRAM from and it now works fine (but 200+MB of memory makes the diag boot excruciatingly slow).

18 years, 5 months

*updating* 8088's

by ajp166＠bellatlantic.net

> >Subject: Re: *updating* 8088's > From: "Chuck Guzis" <cclist at sydex.com> > Date: Wed, 21 Nov 2007 16:27:41 -0800 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On 21 Nov 2007 at 18:11, Jim Leonard wrote: > >> Could you quantify "lame"? I used a 386sx-16 for years and it was >> always faster (visibly, not just via benchmarks) than the 12MHz 286 I >> had access to. > >My own experience was the opposite. I had a 16 MHz 386sx that was >visibly *slower* than a 12MHz 286 that I also had. It was very >cheap and eventually just quit working reliably all on its own. >Perhaps that was an artifact of early SMT. OTOH, I still have a >couple of 386DX systems that have worked flawlessly since the day I >bought them. One uses DIP for memory; the other uses SIPPs. I have a SIIG 3000 Is a 3x4x12" box with VGA, RS170 video, 2 serial, 1 printer port and one slot for modem or NIC. IT's 386sx1/6 and my only beef with it is it maxes out at 5mb (1mb installed and 4mb of simms). Runs good uses wall wart for power and makes a killer linux router/nat box with a 400mb drive and 3.5" floppy. Beside being a good router it's small, a good reason to keep it. Allison > >So, perhaps my own was a victim of bad design. I never was even >tempted to purchase another, so bad was my experience. It's short life and bad design may be an indicator. Allison > >Cheers, >Chuck

18 years, 5 months

Teaching kids about computers...

by evan＠snarc.net

And don't forget Lego Mindstorms! Doesn't teach the hardware but it is much more fun than I ever had in LOGO back in the fourth or fifth grade ... I forget which. -----Original Message----- From: Michael Lee <mikelee at tdh.com> Subj: Re: Teaching kids about computers... Date: Wed Nov 21, 2007 11:17 am Size: 3K To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> This is actually one of the topics I'm most interested in. I gear my collection towards teaching and showing kids, as well as the nostalgic adults. Over the years, I've been surprised by some of the reactions, so I found it best to adapt to the interest level of the audience. For fundamental computing and electronics, it seems to be best to go back to the basics. A lot of the books available either go too much into the history of computing, or get into topics/details that quickly lose the interest of a kid. It seems to be best to relate something they are used to in modern day and work back to the origins. For example, a xbox, it's basically a computer, it has a CPU, hard drive, memory and then other "blocks" such as graphics processing, networking etc. Those are easy to relate back to "how it works." Basic I/O, what is actually on the game disk, how and what makes "online" work, and what the machine is doing in the background. This easily then can lead to small projects and some programming. From there it can be basic logic functions (AND/OR/NOT) and the simple concepts of programming and making things happen. Depending on the interest and geek level of the kid, there are many hobby books that explain this well. I don't know if "vintage" computers is the best way to start as I found a lot of kids (esp. 9yo) are turned off by "it's just old crap" But can easily lead into more of the origins. Something "new" is good to start. There are a good number of hobby kits like the BASIC STAMP now that can teach both the electronics and computing aspect, which then can lead into other things. A little simple micro-controller kit, with a little instruction on logic, electricity and electronics can go a long way. Making stuff, and making stuff happen is always a plus, so a soldering iron lesson with an interesting kit always works too. But once again, all depends on the interest level. Mike Lee Geek Museum A funny story with where things might lead: I got a rotary dial phone in my collection to use with an acoustic coupler. A four year old sees this, and has no problem with the phone, nor the rotary dial. He understood the concept it's just a different user interface, but what got him was that it was wired down. He had never seen a phone handset with a cord attached. So this lead to interesting show and tell about telephone technology to a four year old. Jules Richardson wrote: > > So the boy (9yr. old) was asking last night about how computers > work... any recommendations for good books for learning the basics > from? I think I started out with a Sinclair Spectrum and its BASIC > manual, but I really don't recall now where I found out about the > fundamental building blocks of [typical] computers and how a CPU > worked. There must be a good 'classic' "how computers work" type of > book which avoids going on about PCs and Xboxen... > > I figure I should find him one of those kids electronics projects kits > too (I think that was where I got my first exposure to logic gates > from at about the same age) and also some old 8-bit machine to play with. > > I can get a Spectrum / BBC micro shipped over in a few months, but > something US-built might be better; any thoughts? I did wonder about a > C64, but maybe it'd be better to start with something a bit more > simple? i.e. probably something Z80 or 6502-based (just because > there's more resources devoted to them), generic cassette data > storage, basic video abilities etc. > > (You know, I don't recall seeing a 'how to introduce kids to vintage > computing' thread on here before :-) > > cheers > > Jules >

18 years, 5 months

"intelligent" disk drives

by dm561＠torfree.net

Date: Sat, 17 Nov 2007 21:59:02 +0000 (GMT) From: ard at p850ug1.demon.co.uk (Tony Duell) Subject: Re: "intelligent" disk drives <snip> >As an aside, IMHO one of the worst mistakes commodore made was that the >8050 could not at least read the disks of the earlier drives. >-tony -------- Sort of unavoidable because to get the 500MB/side they went to 100TPI drives. Not as big a problem then as it may be today, because the high price of the 8050/8250s tended to put them into a different market, mostly business and institutional, where price and compatibility with the smaller and cheaper units wasn't usually an issue. And of course the IEEE bus was compatible so you could easily convert among drives (until the serial versions came along) as long as you had one of the (also expensive) IEEE<>IEEE cables. m

18 years, 5 months

Keyboards (in general)

by tsw-cc＠johana.com

woodelf <bfranchuk at jetnet.ab.ca> wrote: > der Mouse wrote: > > > I don't recall seeing a computer keyboard that *is* lowercase, ever. > > Modern keyboards are generally connected to systems that map alphabetic > > keystrokes to uppercase and lowercase depending on other state, and > > have keys ("Shift") designed to provide that state, but the keyboards > > themselves have only one case of alphabetic key, and in every case I > > can recall seeing, that case is upper. > > I stand corrected ... the only keyboard without a shift key I have seen > is a TTY's. > > > /~\ The ASCII der Mouse > > \ / Ribbon Campaign > > X Against HTML mouse at rodents.montreal.qc.ca > > / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B > > You are a bit mistaken. TTY's DID have shift keys. On the five level machines (28, 32, etc.) there was a LETR and FIGS shift. On later machines, like the 33 and 35, there was an actual key labeled 'SHIFT'. While it didn't make upper and lower case letters, it did take the alternate graphic on the keyboard. On the 33/35 machines, it used a "bit paired" sequence where the difference between the 'shift' and 'unshifted' code was 0x20. This led to some weird pairings like '+' and ';'. Some shifts were locked out (zero might have shifted to be space, and vice versa, but they were separate keys. Later model devices, Teletype 37 comes to mind, had both upper and lower case. Many early CRT terminals didn't have upper case letters either. The ADM-3 had lower case as an option. Some of the portable Silent 700's (I remember having one) didn't have lower case. Those that had lower case used 'miniature letters' not ture lower case. I'm sure there are other examples. Keypunches are another catagory. ____________________________________________________________________________________ Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ

18 years, 5 months

*updating* 8088's

by ajp166＠bellatlantic.net

> >Subject: Re: *updating* 8088's > From: woodelf <bfranchuk at jetnet.ab.ca> > Date: Mon, 19 Nov 2007 20:39:49 -0700 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Chuck Guzis wrote: > >> Well, there's clock speed and then there's "apparent clock speed". >> Let's see, a 16MHz 80386sx is equivalent to what, a 10MHz 80286? Actually it's teh other way around the 386 was more efficient than 286 for the same clock speed. >So what speed does the memory run at is my question and how wide? The SX narrows teh bus bandwidth so the memory is cycled either faster to make up for it or has fewer idle states (bus availability). that meant using 60ns 30pin simms. >Playing around with homebrew micro design I am working on, a 500 ns >memory cycle ( 2Mhz ) is about as fast as you can go with standard >parts about 150 ns access time. My limiting factor is not memory >speed but EEPROM and I/O chips dead slow speeds. Those speed limits are consistant with pre 1978 parts for ram and even in 1979 I had some semistatic rams that were 200ns. Eproms were always slow and didn't break the 250ns barrier until around 82 but the mask roms were quite a bit faster. I build with 6 and 10mhz z80s and 12mhz 8085s I have and theres little problem with finding static rams and Eprom (and EEprom) that can keep up. I say little problem as I can find plenty of parts that way too fast in non-DIP formats. If I need faster I can easily find CMOS static rams in the under 25ns range (486dx used 32kx8 and even 64kx8 15ns parts for cache) and larger EE/Flash/Eproms in the sub100ns range. Even back in 1982 I could get power hungry 2147(4Kx1) and 2167(16kx1) parts in the 45ns range. Drams even first out 4164s were under Tcy of 300ns. Old Eproms in the pre8K sizes (2716, 2732) were never fast but 27C256s that do 150ns are really old parts and 27C010s I have are 150ns for the slow parts. Zilog peripherals can be found still at 4mhz and the 8085/8088 (82xx) parts were good to 5mhz with later ones (82Cxx) good to 125ns. Allison >> Cheers, >> Chuck > >

18 years, 5 months

Windoze reqs

by dm561＠torfree.net

Message: 16 Date: Wed, 21 Nov 2007 18:23:49 -0500 From: Sridhar Ayengar <ploopster at gmail.com> Subject: Re: Windoze reqs To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Message-ID: <4744BE05.3090903 at gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Fred Cisin wrote: >>> There was Win3.0 (prolly same requirements) >> 3.00 would (and did) run on 8088. One of the font editors that I used >Not only that, it worked properly with a CGA. >Peace... Sridhar -------- And the much higher def monochrome graphics cards commonly installed in the clones (no colour of course). m

18 years, 5 months

*updating* 8088's

by chrism3667＠yahoo.com

We've all seen different varieties of 8088 to 80286 upgrades. A few at least plug into the 8088's socket. I saw a '286 to '486 upgrade (must have been similar in that respect) at a show a while back (didn't buy it). We also know about OverDrive products. What would happen if you pig-piled all these things in an old 8088 machines? What would happen? Cataclysmic explosion? Were there ever 8086 to 80286 upgrades for the few machines that used them? ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs

18 years, 5 months

VAXmate for Windows

by ajp166＠bellatlantic.net

> >Subject: Re: VAXmate for Windows > From: Adrian Graham <witchy at binarydinosaurs.co.uk> > Date: Mon, 19 Nov 2007 12:51:54 +0000 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On 19/11/07 06:54, "Zane H. Healy" <healyzh at aracnet.com> wrote: > >> At 9:23 PM -0800 11/18/07, David Griffith wrote: >>> I have seven 5.25" floppies labeled as RX33K which contain: >>> >>> VAXmate MS-Windows v1.03 (two disks) >>> VAXmate Info System v1.1 >>> VT240 Emulator Update >>> VAXmate S/A Install v1.1 >>> VAXmate MS-DOS v3.10 >>> >>> All of these are labeled "For VAXmate operating environment v1.1". >>> >>> I don't remember where it came from, but there's been some recent talk >>> about VAXen. Who wants these? >> >> I assume these will only run on a VAXmate? I've only seen one >> VAXmate and that was nearly 10 years ago. How good was the VT240 >> emulation? > >I never tried the full graphics side of things on the emulator, but as a >terminal it was great, a novelty in those days to have a black-on-amber >display too! > >We have 2 VAXmates at Bletchley Park so if those floppies could wing their >way across the pond that'd be great! I keep meaning to drag them out of >their storage room and set at least one up to exhibit, we're building an >Electronic Office exhibit that the VAXmate should be a part of really. If the VAXmates have the optional hard disk box mind the cooling if RD32 (ST250? 40mb) as it ran very hot and tended to fail. The RD31 (st225 20mb) was lower power, cooler and far more reliable. If you make it operational the VAXmate was a PCSA(Pathworks) terminal with Ethernet access to shared and private files on VAX/OpenVMS. The result made it a very useful system. Typical VAXmate had 2MB of ram some had 4, back then that was a large amount. Allison >-- >Adrian/Witchy >Binary Dinosaurs creator/curator >Www.binarydinosaurs.co.uk - the UK's biggest private home computer >collection? >

18 years, 5 months

Apology

by dm561＠torfree.net

I've been chastised off-list for forgetting to change the subject header on a few recent posts from its digest default; for anyone else whom I've inconvenienced, my apologies and I'll be more careful in future. mike

18 years, 5 months

Teaching kids about computers...

by compoobah＠valleyimplants.com

Perhaps not right now, but the biggest "leap forward" I had from books was looking at the 8080/Z80 microcomputer design and operation books (such as Ciarcia's "How to Build Your Own Z-80 Computer" and "Microcomputers and Microprocessors" (8080, 8085 and Z-80) from the hardware standpoint. Probably not a good book until Junior High or High School, though. When I was learning S/W, I remember starting with Logo in 4th grade and using Brainpower ChipWits at home. the ChipWits manual had a small section on programming theory, perhaps I can find it. That's a good game if you have an older Macintosh around (I had issues on machines with over 1MB of RAM - it was written for the 128K, 512K and XL per the disk. Some other people don't seem to have the issues, perhaps there was a revision). In middle school we moved on to BASIC (because it was in the ROMs of Apples). Perhaps not the ideal progression, but nowadays students in the elementary schools don't seem to be learning programming at all- it's more "how you use application software on the computer". In the early '90s Macworld had a 3-part article on how computers work that wasn't too in depth. If you want I can find it and scan it., but it's probably not too much more in depth than David Macaulay's "The Way Things Work" in the new edition. (actually it is)

18 years, 5 months

Documentation for the AT&T Sceptre Videotex terminal

by dm561＠torfree.net

Date: Tue, 20 Nov 2007 17:43:31 -0700 From: woodelf <bfranchuk at jetnet.ab.ca> Subject: Re: Documentation for the AT&T Sceptre Videotex terminal Richard wrote: > Ack! Yes, the keyboard looks painful. I don't think they envisioned > that people would actually type on this thing, more like hunt & peck. That has to be the 2nd worst keyboard I have seen. The 1st is any keyboard with 'windows' keys. Considering Videotex was ment as information setup it was more like press 1 to display ... 9 to return to menu type stuff. Ben alias woodelf --------------- You're not really a big PC & Windows fan, are ya? The 'windows' key's never bothered me; how does it disturb you? m

18 years, 5 months

Falco Terminal

by dm561＠torfree.net

Speaking of keyboards etc.: Anybody have a use for a Falco VT5220e, as used by many DECcies whose budgets couldn't afford a 'real' VT200? Looks just like the picture of the Infinity (amber CRT) at: http://williambader.com/museum/vax/vaxhistory.html Might also have one of the older TS-100SPs somewhere (VT100). And a L-S ADM-11... Unfortunately, although I have boxes of Falco docs the 5220 manual seems to have gone missing from the pile (at least I haven't found it yet), although I do have docs for the ADM-11, and the TS-100 if I can find it. m

18 years, 5 months

Documentation for the AT&T Sceptre Videotex terminal

by jeffj＠panix.com

Re: Documentation for the AT&T Sceptre Videotex terminal (Richard) > http://steinbeck.ucs.indiana.edu/~mmeiss/sceptre/ Wow, those photos bring back memories! I was just thinking about those: a friend had one and google didn't help me. ebay lists Sceptre flat monitors (totally unrelated but a source for confusion). I have something similar: I think it's Zenith. A thick keyboard with the terminal inside the keyboard, it attaches to tv-as-monitor, phone line (internal modem). My Olivetti PR2300 spark-jet printer has line-drawing characters that I don't recognize. Was that intended for teletext/videotext? Yes, I bought it from the DAK catalog after reading the glowing ad how it was a wonderful printer for the low low price. Nowhere did it mention it was a ONE PIN DOT MATRIX PRINTER! It made the dots by creating sparks (ozone!) that fused the powder to form ONE DOT on the paper. Somewhere I have some floppy disks with teletext/videotext software so one could use a PC instead of a dedicated terminal. I remember the computer show around 1990 when several companies /truly believed that Videotex would be the future in the USA/ so they were trying to get customers and data-suppliers/stores online. Also being tried at that time: phones with built-in teeny terminals for folks who didn't want the cost or responsibility of a PC. Geez, those were re-invented how many times: as the CIDCO email only terminal, thin clients, Network appliances (I-opener), ...

18 years, 5 months

Fwd: My Relay Computer

by grant＠stockly.com

>Date: Mon, 19 Nov 2007 20:44:43 -0800 >From: Harry Porter <harry at cs.pdx.edu> >Subject: My Relay Computer >X-Mailer: Apple Mail (2.912) >X-Greylist: Sender succeeded SMTP AUTH authentication, > not delayed by milter-greylist-2.0.2 (ehlo.cat.pdx.edu [131.252.208.106]); > Mon, 19 Nov 2007 20:45:33 -0800 (PST) >X-Virus-Scanned: ClamAV 0.91.1/4853/Mon Nov 19 19:05:00 2007 on >ehlo.cat.pdx.edu >X-Virus-Status: Clean >X-pstn-levels: (S:77.05695/99.90000 R:95.9108 P:95.9108 M:97.0282 C:98.6951 ) >X-pstn-settings: 3 (1.0000:1.0000) s gt3 gt2 gt1 r p m c >X-pstn-addresses: from <harry at cs.pdx.edu> [34/2] >Original-recipient: rfc822;grant at cmosxray.com > >As you may recall, I built a computer out of relays. > >My records indicate that, at one time, we exchanged email about this computer. > >I wanted to let you know that I have recently added to the webpage >for the computer. > >First, I added a thorough document describing the design in detail: > ><http://web.cecs.pdx.edu/~harry/Relay/RelayPaper.pdf>http://web.cecs.pdx.edu/~harry/Relay/RelayPaper.pdf >http://web.cecs.pdx.edu/~harry/Relay/RelayPaper.htm > >Second, I produced an educational video, which can be accessed >through this page: > ><http://web.cecs.pdx.edu/~harry/Relay/VideoTutorial/index.html>http://web.cecs.pdx.edu/~harry/Relay/VideoTutorial/index.html > >The main page, with all the photos of the machine, is still at: > ><http://web.cecs.pdx.edu/~harry/Relay/VideoTutorial/index.html>http://web.cecs.pdx.edu/~harry/Relay/index.html > >Be well, > >Harry Porter > >HarryAndMachine.jpg > > >RegCloseUp.jpg >

18 years, 5 months

Keyboard layouts

by dm561＠torfree.net

------------Original Message: Date: Wed, 21 Nov 2007 12:00:19 -0700 From: woodelf <bfranchuk at jetnet.ab.ca> Subject: Re: Documentation for the AT&T Sceptre Videotex terminal Richard wrote: >> Well, yes, obviously the location is the issue, but it is still just another >> tedious MS-bash; I've got an APL keyboard here, and I think every >> "classic" terminal or computer keyboard I have here is different in >> some "improved" way but I don't hear complaints about that, or all the >> different PC layouts, especially the enter, backspace and \ keys. > > Exactly. I did ... see windows keyboards. But then I am cheap, I don't spend money on a real keyboard. Not that I have seen a modern keyboard I did like. -------------Reply: Different keyboard layouts have been a fact of life since the very first one that wasn't the same as a typewriter; deal with it. Find yourself an old one that you *do* like (if such a thing exists) and spare us your bitching and moaning. Back to our regular programming... m

18 years, 5 months

keyboard layouts

by dm561＠torfree.net

----------Original Message: Date: Wed, 21 Nov 2007 09:57:37 -0800 (PST) From: Cameron Kaiser <spectre at floodgap.com> Subject: keyboard layouts was Re: Documentation for the AT&T Sceptre Videotex terminal > Don't you also have trouble switching from a C64 to a Mac? Yup. Fortunately most of the emulators let you either use 64 or Mac layouts and map the keys appropriately. ---------Reply: There ya go. Like most of the bitching about MS, Windows, keyboards, etc. here and elsewhere, if you don't like it just shut up and use something else; lots of alternatives like Linux & KBs w/o WIN keys out there and we've heard it all K times. (Meant for the OP, not you Cameron). m

18 years, 5 months

"intelligent" disk drives

by dkelvey＠hotmail.com

> From: tshoppa at wmata.com > Chuck wrote: >>Micropolis floppy drives were very well-made. I wish that modern >>drives could be as well-built. All of mine are still operational. > > I think that like CDC/Imprimis, Seagate, Shugart, etc., Micropolis > built drives to different price points for different markets. > > The ones built for the mini and mainframe market in the late > 80's/very early 90's are true tanks and stand up very solidly > here 15 or 20 years later. > > But by the mid-late-90's when capacity was the craze I think that > some industrial-duty Micropolis drives were a little too bleeding > edge. > > The MFM ones built for PC-clones, however, seem to simply be "above > average", which is pretty good but not stellar. > > In the late 90's, we were using Micropolis drives in our HaL computers. Many wouldn't even finish our 24 Hour burn-in. When they were making choices as to which drive to use, I was surprised when I was told that they'd go with the Micropolis drive. By that time, they'd already earned a bad name. I was told that the decision was made, based on that fact that they would give us any engineering support we needed. I saw this as a red flag but the upper people didn't. I couldn't understand why we would need any support for something as mature as hard drives of the time. I suspect that bad marketing decisions were made at Micropolis, like the ones that were made at HaL. Engineering didn't have there act to gether before the products were in production. I've seen it happen at otherplaces. Schedule is king and at some point the engineers will just stand and nod their heads ( as they get their resumes ready ). Dwight _________________________________________________________________ Share life as it happens with the new Windows Live.Download today it's FREE! http://www.windowslive.com/share.html?ocid=TXT_TAGLM_Wave2_sharelife_112007

18 years, 5 months

Teaching kids about computers...

by James＠jdfogg.com

> So the boy (9yr. old) was asking last night about how > computers work... any recommendations for good books for > learning the basics from? I think I started out with a > Sinclair Spectrum and its BASIC manual, but I really don't > recall now where I found out about the fundamental building > blocks of [typical] computers and how a CPU worked. There > must be a good 'classic' "how computers work" type of book > which avoids going on about PCs and Xboxen... One weekend my parents wanted to get away from the kids so I went to work with my older brother. I was in a lab at P.R. Mallory Corp. with a supply of chips and a few books. Worked for me. At 12 I built an 8080a based something or another (I wouldn't call it a computer, but it had a bit of memory, a numeric keypad and 6 A/N LEDs for display). After that I had accounts on about 6 minis of the DEC and DG variety. Are you sure the kid is interested in computers or just trying to keep up with the alphageeks at school?

18 years, 5 months

Access to IOPAGE Registers using PDP-11 Opearting Systems

by dave＠mitton.com

>Date: Tue, 20 Nov 2007 21:17:18 -0500 >From: "Jerome H. Fine" <jhfinedp3k at compsys.to> ... >I doubt that RSX-11 or RSTS/E allow a user access to the IOPAGE >even via PREVIOUS DATA space. Can anyone confirm this assumption? >Is there any fast method (only a few extra instructions) that would allow >a user to reference a specific IOPAGE register from a user program? Are >VIRTUAL arrays allowed in FORTRAN under RSX-11? If so, how >is access to the MMU registers controlled and allowed? > ... >Sincerely yours, >Jerome Fine >-- Ouch, you're straining dead neurons.... As the KMC-11 Development Tools developer for RSX-11M and VMS, I know it's possible. I just don't remember the all the hoops we jumped through to do it. (this was circa 1978/79) The basic approach required us to map the IO registers and peek and poke values in the registers to control execution. Of course this was all written in MACRO-11, not un-manly FORTRAN. ;^) You probably had to be an RSX admin user ( UID below [10,*] ) to run the tools (loader and debugger). On VMS I had to learn the very new facility (I don't think it was in V1.0) of Page Frame Mapping and allocate a page map to get to UNIBUS IO space. This required a specific privilege too. I ported the tools code from Macro-11 to VAX Macro by doing semi- mechanical find/replace on the opcodes, and other tweaks. I even created a few macros to mimic the missing PDP-11 instructions, like SWAB. It needed very little needed rewriting to get working. Dave.

18 years, 5 months

Teaching kids about computers...

by evan＠snarc.net

There is a good book called "The Chip" by T.R. Reid. Mostly it's the story of Noyce and Kilby (which is well-told and worth reading on its own), but there's a chapter for laypeople about how a chip actually adds two numbers together. Way too simple for cctalk'ers, but great for a 9-year-old. -----Original Message----- From: Scott Quinn <compoobah at valleyimplants.com> Subj: Re: Teaching kids about computers... Date: Wed Nov 21, 2007 11:09 am Size: 1K To: cctalk at classiccmp.org Perhaps not right now, but the biggest "leap forward" I had from books was looking at the 8080/Z80 microcomputer design and operation books (such as Ciarcia's "How to Build Your Own Z-80 Computer" and "Microcomputers and Microprocessors" (8080, 8085 and Z-80) from the hardware standpoint. Probably not a good book until Junior High or High School, though. When I was learning S/W, I remember starting with Logo in 4th grade and using Brainpower ChipWits at home. the ChipWits manual had a small section on programming theory, perhaps I can find it. That's a good game if you have an older Macintosh around (I had issues on machines with over 1MB of RAM - it was written for the 128K, 512K and XL per the disk. Some other people don't seem to have the issues, perhaps there was a revision). In middle school we moved on to BASIC (because it was in the ROMs of Apples). Perhaps not the ideal progression, but nowadays students in the elementary schools don't seem to be learning programming at all- it's more "how you use application software on the computer". In the early '90s Macworld had a 3-part article on how computers work that wasn't too in depth. If you want I can find it and scan it., but it's probably not too much more in depth than David Macaulay's "The Way Things Work" in the new edition. (actually it is)

18 years, 5 months

Access to IOPAGE Registers using PDP-11 Opearting Systems

by jhfinedp3k＠compsys.to

When I run under Ersatz-11, John Wilson allows INSTALL EMEM.DLL (this was under V3.1 of E11 and hopefully soon with EMEM32.DLL under V5.1 of E11) to access many MegaBytes of PC memory via an IOPAGE register. For example: BaseReg = 177100 BaseRe2 = BaseReg+2 BaseRe4 = BaseReg+4 BaseRe6 = BaseReg+6 Mov @#BaseReg,R0 ;Get the current value from PC memory Mov R0,@#BaseReg ;Put the current value into PC memory BaseRe4 / BaseRe6 are used as a 32 bit address into the PC memory allocated during the INSTALL process. Under RT-11, direct access to the IOPAGE (address above 160000) is allowed even using VBGEXE by a reference to PREVIOUS DATA space. I have written FORTRAN IV/77 interface subroutines to allow a user to easily access that memory rather than use VIRTUAL arrays which are much slower and have much less capacity. I doubt that RSX-11 or RSTS/E allow a user access to the IOPAGE even via PREVIOUS DATA space. Can anyone confirm this assumption? Is there any fast method (only a few extra instructions) that would allow a user to reference a specific IOPAGE register from a user program? Are VIRTUAL arrays allowed in FORTRAN under RSX-11? If so, how is access to the MMU registers controlled and allowed? Johnny has helped with such RSX-11 questions in the past and the answers were appreciated very much! Sincerely yours, Jerome Fine -- If you attempted to send a reply and the original e-mail address has been discontinued due a high volume of junk e-mail, then the semi-permanent e-mail address can be obtained by replacing the four characters preceding the 'at' with the four digits of the current year.

18 years, 5 months

TTL input Trinitron monitor

by ard＠p850ug1.demon.co.uk

I've found the Torch XXX hardware docs, which cover that little Trinitron monitor I mentioend It's quite small, probably a 12" CRT. Inside are the following PCBs : FA (PSU), with a control daughterboard. This gives 120V DC from the mains (SMPSU), all other voltages come from the flyback transformer DA (Scan) with a convergence daughterboard. CRT base (icnludes video output stages) BA (Video) H (rear panel controls) Input socket (not Sony, this is a Torch PCB) The input socket PCB connects to the video PCB by a 10 wire jumper. 4 of the wires are grounds, the 6 siganls are R, G, B, Y(== I on a CGA interface), HSynch and Vsync. The Torch socket PCB doesn't connect to the Y signal at all, but then Torch machines had analgue RGB outputs and the BBC micro had 3-bit TTL video, so this would be no problem for the intented applications. Tehre's a 3 position slide swtich on the back to select the input mode. The possiblities are analogue RGB, 3-bit TTL RGB (8 colours) and 4-bit TTL RBGI (CGA compatile, it does get the brown colour right). It's strictly TV-rates only (not EGA or VGA), but it does work with both US and European rates. -tony

18 years, 5 months

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