test-drb February 2003

test-drb@ccmp.vtda.org

337 participants
780 discussions

TS2068

by acme＠ao.net

From: Al Hartman <alhartman(a)yahoo.com> Subject: Re: Check out this TI99/4 on eBay Date: 02/26/2003 7:42 PM > > From: "TeoZ" <teoz(a)neo.rr.com> > > > > My first computer was a timex 2068 and learning to > > program on chicklet keyboards sucks. > > But.. Those were pretty nice computers... Still are :>) > Originally, it was intended to be an American Version > of the 48k ZX-Spectrum Computer. > > But, as-is it wouldn't pass FCC regulations. Not to doubt your word, but what is your source for that information? I've had several conversations with George Grimm (President of Timex Computer Corp.) and he never mentioned a problem with the FCC. > I have a U.S. Prototype of the Spectrum, a Microdrive I would be interested to see photos of the prototype. Do you have any Web space you can post photos to? > The company I worked for in the 80's even made a > drawing program similar to MacPaint for it, called > TechDraw, A Spectrum Emulator Cartridge, Disk System, > Terminal Software (for the Timex Modem), and lots > more... Mind if I ask the company name? Later -- Glen 0/0

23 years

ASR-33 vital poop

by gil＠vauxelectronics.com

Hi folks: This is a summary of input from many people, manuals, and prior notes of mine. The initial question was of the differences between the standard Teletype 33, and the version provided for DEC systems. But I have also added some sundy stuff as well. Let me know of any corrections/additions. Standard Teletype "Private-wire" ASR-33 (aka M33-asr): ------------------------------------------------------ - The right side module is the CCU (Call-Control-Unit). The "private-wire" version is for current-loop operation, and has a blank top plate. It is normally configured for 20-mA (but can be jumpered for 60-mA). - The paper tape reader is also called a TD (Transmitter-Distributor), a legacy term from early Teletype days. - The "standard" tape reader has a 3-position lever: START/STOP/FREE. - An optional "auto" tape reader has a 4-position lever: START/AUTO/STOP/FREE. In the AUTO position, the reader can be commanded on/off remotely. The DC1 (XON) and DC3 (XOFF) control characters are used as start/stop commands for the auto tape reader. Since XON/XOFF chars are used today as software-handshaking flow-control characters, you want to disable software handshaking if you are connecting to a PC. - There is a little circuit board mounted in the pedestal stand which provides power for the tape reader. In later 3300-series machines, this was finally built into the CCU. - from Jack Hart: The Model 33ASR with the "Auto" TD feature had a different TD control/power board underneath the machine in the back. It had a relay that was controlled by either the momentary "AUTO" switch or a stuntbox contact on the printer. There was another feature controlling the TD when the 33 was configured for TWX. When a connection to the the other end was established, the distant machine's answerback would trip and then send an "X-ON" to start the tape at the calling machine. The X-ON was actually programmed onto the end of the answerback drum sequence. Sometimes the modem itself would send the contact closure to trip the TD based upon seeing the RS232 Carrier Detect and/or the RTS/CTS leads change states. DEC LT33 (DEC-modified ASR-33): ------------------------------- - The CCU is a standard private-wire current-loop (blank plate). - Has an 8-position connector (mate-n-lock/molex?) with 6 pins populated. Two wires for transmit loop, two for receive loop, and two for reader control. Can be wired for full-duplex (two loops), or half-duplex (rx and tx wired in series to one loop). - Uses the standard tape-reader (3-position lever: START/STOP/FREE) - The pedestal has a small circuit board with the control relay . (and reader power supply as well?) (and DEC interface cable?) There are a couple of cables connecting it to the CCU. - from Jim Haynes: There was a 6-wire cord and they were full duplex; two wires for transmit, two for receive, and two for reader control. They didn't use the X-on X-off characters for reader control. The CCU was just a plain private line blank plate. What I can't remember for sure is how the reader worked. I'm pretty sure they let the distributor step the reader, and just had a relay to enable/disable it. Seems like I remember a reed type relay. I guess there was a power supply in the base for the reader step magnet in any kind of ASR. No doubt the printer loop current was 20ma - no reason to use 60 when you can use 20. I don't know if the keyboard used a 20ma loop or if it just used the thing as a dry switch. But you'd probably want 20ma or so in it to be sure the contacts are kept clean. - from Jack Hart: The DEC Model 33's has a simple circuit board attached to the Call Control which was operated by the computer (I think the computer would send a contact closure to the board on two leads or maybe it sent a voltage to the relay...I never used it). That board had a reed relay which was in series (or was it parallel?) with the switch on the (standard) TD. It couldn't use the "auto" TD since it wouldn't be able to stop the TD. The computer actually turned the TD on and off with the contact closure. The Model 33 usually had a six-wire straight Molex-type of connector for the DEC interface. I think the keyboard contacts were on one pair, the selector magnet driver input on the next pair and then the TD control relay on the third pair. - John Francini provided this: http://www.chd.dyndns.org/pdp8/ It includes: - Teletype Model 33 Line Set wiring printouts - DEC LT33 Teletype Modifications Print Set - some scanned 33 manuals are at: http://highgate.comm.sfu.ca/pdp8/ Gil's Random M33 notes: ======================= CCU (Call-Control-Unit) ----------------------- The right side module is the CCU (Call-Control-Unit). Here is my limited knowledge on the interfaces available; the 33s all have some version of CCU, it's just a matter of which one. The most common CCU (I presume) was the simple interface to a 20-milliamp dc loop (or 60-mA) for "Private Wire Service." This one had a blank panel on top and a LINE/LOCAL knob sticking out the front of the case. This is the model that usually got hooked up to computers or to dedicated lines. Then there was a "Computer-I/O" CCU, which had six square buttons sticking out the top (at the front), plus a power button above those. It had a bunch of TTL-logic-level signals as well as a current loop, I believe. One of my 33 manuals discusses this one (others do not) -- it says it has a 20-pin connector, with a bunch of signals that look to be TTL-level. I have not heard of anyone owning one of these computer-i/o units. The "TWX" (Teletypewriter Exchange) machines had a CCU for "Switched-Network Service," which used an external "dataset" (modem) that mounted in the stand, and connected to a conventional telephone line, using FSK tones for communication. These had either a rotary dialer or touch-tone keypad for dialing the phone number, a speaker at the front, six round buttons sticking out the top at the front, four more button/lights up in the middle of the panel, and an optional way-cool auto-dialing card reader. My M33 is a Western-Union-branded TWX machine that has a UCC-3 CCU, with the touch-tone dialer and a 101D modem in the stand. I think almost all computer modems can talk to this M33 modem, when they fall back to the lowest standard (Bell 103?). I think these may have been a moderately-common machine. There was also a UCC-39 CCU which had a built-in modem (but still connected to an external line interface of some sort), and had six square buttons sticking out the top. I think this was used for TWX service also. I don't know how common these were. Then there was a CCU for "Circuit-Switching Service," which apparently refers to "Telex" service, which used a network of private lines. This CCU had a rotary dialer and four round buttons. This is found in Model 32 (baudot) sets, not Model 33 (ascii) machines. The dialer is not for telephone calling -- the unit connects to a special neutral or polarized DC wire line system, and the dialer pulses the line to call a station. It is operationally similar to TWX machines (that used a modem on the phone lines), but it used a special dc line network and central switching system. Interfacing -- Data Format -------------------------- Baud: 110 Data bits: 7 Parity: Even, or Mark Stop bits: 2 Flow-ctrl: None As I understand it, most 33 keyboards generated even parity (but early ones used bit-8 always marking). If you have a terminal emulator set for 8-data/no-parity, the chars will have bit-8 high when the parity bit is marking (for half the chars typed on the 33 keyboard) -- bit-8 high is non-standard ascii, and the terminal may display ibm-extended chars or something else. I believe bit-8 is ignored by the 33 printer, so you should be able to send chars to the 33 when the terminal is set to 7-data/any-parity, or 8-data/no-parity. However, 1-stop bit may be a problem for the 33 to keep up with streaming data. Also, you don't want flow control set to xon/xoff if your 33 has the special option for an auto-tape-reader (it would have the 4-position lever, not 3-pos). Interfacing -- Private-Wire current loop ---------------------------------------- The transmitter loop output is effectively a series connection of the keyboard and tape reader sections (via the rotating distributor). Electrically the TX loop looks just like series switch contacts. The receiver loop input connects to the an electronic circuit, and is polarity-sensitive. It is usually configured for 20-mA, but can be jumpered intenally for 60-mA operation. I have used it with a 30V loop supply, and am told it runs fine down to a 12V loop. The max voltage for the loop is unclear -- I have seen 45V and 70V listed as the max (I'll stay at 30V to be safe). For full-duplex operation, the TX and RX lines connect to two externally-powered loops. For half-duplex operation, the TX and RX lines connect in series to one externally-powered loop. There is an internal loop supply, but it is used in local mode only, so that the keyboard can drive the receiver. I have some schematics for rs-232-to-current-loop converters at: http://www.vauxelectronics.com/gil/tty232/ Interfacing -- TWX dataset (modem) ---------------------------------- For TWX machines with a dataset (modem), you should be able to connect to it (at 110-baud) using a 300-baud computer modem. 300 may be the lowest rated modem standard, but they pass anything up to 300-baud, as they are a simple fsk (freq-shift-key) design, using two tones for tx (mark/space), and two tones for rx (mark/space). The definition of which freq-pair is tx, and which is rx, determines which end is "originate" and which is "answer." Paper Tape Readers ------------------ The "standard" tape reader has a 3-position lever, labeled START/STOP/FREE. An optional "auto" tape reader has a 4-position lever, labeled START/AUTO/STOP/FREE. In the AUTO position, the reader can be commanded on/off remotely. The DC1 (XON) and DC3 (XOFF) control characters are used as start/stop commands for the auto tape reader. Since XON/XOFF chars are used today as software-handshaking flow-control characters, you want to disable software handshaking if you are connecting to a PC. There is a little circuit board mounted in the pedestal stand which provides power for the tape reader. In later 3300-series machines, this was built into the CCU. 3300-Series typewheel/keyboard for "latest" ASCII code, variable customer-activated options (auto/manual tape punch, auto CR/LF function, even-parity keyboard...), and included, as standard, various features that were previous options (paper-low/out sense, DC1/DC2/ENQ/EOT function contacts, end-of-line space suppression...). My manual shows that they have a one-piece cover, so the tape reader/punch didn't look added-on -- but I think early 3300 units had original covers (separate covers for the reader and punch, like the classic asr). The 3300 CCU (Call-Control-Unit) for "private-wire" service (20-mil loop) also included the power supply for the tape reader. Earlier 33s had this little board mounted in the stand. Longevity ---------- The M33 (and the baudot M32) were designed for light-duty use. They did not heat-treat parts, adjusted some things by bending parts... The 33/32 just seems to wear out after a while -- someone said about 1500 hours of runtime will be about it. The elapsed-hour counter in my 33 says 1495, so I should have a good 5 hours left! Your unit may or may not have an elapsed-hour meter, since it was an option. Before you spend big bucks on ebay ---------------------------------- A Model 33 has a four-row keyboard (not including the space bar). A Model 32 has a three-row keyboard (not including the space bar). The 33 is ascii, and the 32 is baudot. You cannot (prctically) modify a 32 into a 33. Documentation ------------- There is a 2-volume desciption/adjustments manual set, and a third parts manual -- the three manuals are often on ebay for $20-$40. Schematics are harder to find. Also check these sites (scroll down): http://highgate.comm.sfu.ca/pdp8/ http://www.chd.dyndns.org/pdp8/ Lubrication ------------ **DO NOT** use WD-40, since it gums up over time. I use 3-in-1 oil for light lubing, 30W motor oil for heavier needs, and lithium grease for gears and cams. Some folks don't even like 3-in-1, and will use a 10W for light stuff. Supplies -------- For paper tape, check out ebay or: http://www.westnc.com/teletype.html Note that the paper-tape for the ASR-33 should be 1" wide, oiled paper. Non-oiled paper or mylar tape will wear your punch pins (so I'm told). The 7/8" or 11/16" paper tape for baudot machines will not work at all. For standard roll paper, check out ebay or: http://www.westnc.com/teletype.html For sprocket-feed paper, you have to special order paper that is 8.5" wide, with the holes on 8" centers. Sprocket-feed machines are pain in the ass, since standard teletype roll paper (or letter sheets) will not feed through, nor will the commonly-available "continuous-form tractor-feed" computer paper which is 9.5" wide, with tear-off sprocket holes. I have located a special-order paper at Office-Max, which is indeed 8.5" wide sprocket-feed, 3500 fan-fold sheets to a box. But this is a "green-bar" computer paper -- I have not found white or buff. I did find an unusal ROLL of sprocket-feed paper once. For platen refinishing, check out: http://www.techspray.com/1612info.htm Teletype used the same ribbon for most of their machines, apparently the same one used in old Underwood manual typewriters. Newer replacement ribbons are nylon and only lightly inked so they don't last as long, but they work fine. I found a decent $3 black ribbon at Staples: Dataproducts #R3300 (replacement for Okidata ML80/82/84/90 printers). SMD (Selector Magnet Driver) Board ---------------------------------- I found un-soldered power resistors on the selector-magnet-driver board in my 33 -- it's a shi**y pcb design, with no thermal considerations at all. I have run across another fellow with the same problem. I repaired it with heavy buss wire and solder. This board amplifies the 20-mA input to 500-mA, for driving the typing mechanism magnet (solenoid). I took some large gauge non-insulated buss wire, and tack soldered several sections of it to the traces from the hot resistor pads (to the next component along the trace). After it was tacked in place, I twisted the wire around the power resistor leads and soldered it, then soldered all along the trace to bond the wire -- this left a nice big mound of solder/wire extending away from each of the power resistor pads. This beefed up the mechanical strength, and added some thermal mass to help pull the heat away from the big frickin' resistor leads. Stuff I need ------------ My 33 is a sprocket-feed machine that uses 8.5" wide paper, with the holes on 8" centers. I'd like to find fan-fold paper in white, buff, or even green-bar. I'd also be interested in rolls of sprocket paper. I could use a copy stand for a 33 (or 32). Also, this TWX machine uses a touch-tone dialer and dataset (modem). It has the UCC-3 version of the 33's CCU (call-control unit), with a touch-tone keypad, and connects to an external 101D dataset. I need to fix the dataset. I have the standard 33 manuals, which have simplified schematics and some theory on the UCC-3 CCU. But, full schematics would let me check things properly. Does anyone have a manual/schematic on the UCC-3? Does anyone have a manual/schematic on the 101D? How about the more-common 101C? Does anyone know the difference between a 101D and a 101C? thanks, gil ;----------------------------------------------------------- ; vaux electronics, inc. 480-354-5556 ; http://www.vauxelectronics.com (fax: 480-354-5558) ;-----------------------------------------------------------

23 years

TRS-80 Model 4 help requested

by alhartman＠yahoo.com

From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com> > A minor complication with using DS drives, at least > as external, . . . > Didn't Radio Shack used pin 32 for drive select 3? > Isn't that "side select"? Yes, they did. I don't remember for sure, but I think that on a Model I, you could only use 3 drives if you decided to use Double Sided Drives. On a Model III/4, it didn't matter as you could use two internal and two external double sided drives without problems (I think...). It's been a while, and my memory is fuzzy on this one. I used to use one DS/DD 40tk as Drive 0:, and two DS/DD 80tk drives as 1 and 2 on my Model I when it ran my BBS. I had an LNDoubler in it, and always meant to get 8" drives to get 1.2mb each instead of 720k. I never did do that. Now, I could put 1.2mb drives on with that, I guess. You could boot from any size media that the controller would support, you'd just have to make a boot floppy on the correct media, as the drive settings were contained in the boot sector of the disk. On a Model I, the boot sector ALWAYS had to be Single Density, no matter what the rest of the disk was. That was the main difference between the Model I and III. While they both had DD capability (the Model I equipped with a Doubler), the Model III required a Double Density Boot Sector. I think that one of Dos'es (MultiDOS I think) would boot on both machines as long as the Boot sector was the correct type. I know one of the Dos'es could do that. I REALLY have to find my dream machine... A complete LNW Model I or Model II (Team) computer... Regards, Al Hartman

23 years

Anyone have Chips & Technologies Super386 documentation?

by vcf＠siconic.com

I need some manuals for the Chips & Technologies Super386 chipset for a client. I am aware of the Programmer's Reference Manual from a web site of the company that produced it, but I have not found any title for the hardware reference. Either would do, the hardware manual would be preferable. Anyone have the manual(s), or at least a title? Any dated reference would be good. This is for a client so there will be money involved if you find it for me ;) -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org * Old computing resources for business and academia at www.VintageTech.com *

23 years

Let the witch trials begin! Re: OT: Re: Going OT Re: (no s ubject)

by Edward.Tillman＠valero.com

What the government can and will do is contained in two phrases: "Manifest Destiny," and "Eminent Domain." The first, Manifest Destiny, was the political doctrine which told everyone it was God's Will that we (Americans) posess, occupy and exploit all the lands between the two native shores of the North American continent. (Canada: ya lucked-out!). The second, Eminent Domain, says that, if you have it, and the government wants it (usually land, but has been applied to inventions as well), they *can* offer you a 'fair price' (usually a paltry pitance), but they can otherwise take what they want from you "in the name of the greater good" -- or, how I lost my farm to an unused interstate freeway (San Jose, Ca). > If the local police can do it, I would guess the federal government > must have some provision that allows them to do what they must, > when they must, also. [demime 1.01a removed an attachment of type application/ms-tnef]

23 years

resurrecting a PDP-11/10

by iamvirtual＠hotmail.com

>From: Ethan Dicks <erd_6502(a)yahoo.com> >Reply-To: cctalk(a)classiccmp.org >To: cctalk(a)classiccmp.org >Subject: Re: resurrecting a PDP-11/10 >Date: Thu, 27 Feb 2003 10:20:54 -0800 (PST) > >--- Fred Flintstone <iamvirtual(a)hotmail.com> wrote: > > Thanks for the assistance to date! > > > > Actually, I have a second M7800 card installed on the PDP-11/10 machine. > >That's handy (and it ends the speculation if you have two SLUs or not ;-) > > > As far as memory, there are two 16kw core systems installed on this > > machine. > >Nice. That should serve nicely. Wish my 11/05 was that well equipped >(but it's in the short box). Yes, I guess I should call it a 11/05. despite what is clearly printed on the console. > > I am needing to know what I am looking for to get RT-11 running. What > > did DEC call their install tapes? eg. Is the > > "RT-11 V03B BIN MT9 1/2" tape the boot/install tape? > >It certainly seems like the distribution tape, but it's not clear to >me that you have a bootable tape there. If your TS03 is working >and you enter in the TS bootstrap and you get text, then it is >bootable. Dunno where you'd find install instructions for v3, though. >It's *possible* that there is a second tape that you boot first, one >with either an MS or MT boot block on it. It's also possible that there >is a boot papertape. Again, that's before my time (I got started with >RT-11 v4 on floppy). This tape is actually the first of two tapes. At this point, I don't know if I have any bootable media. > > Is RT-11 the easiest O/S to get installed? > >Yes! > > > I want to get to a point where I > > can verify the hardware is all running. > >RT-11 or XXDP (DEC's low-level diagnostic monitor) are the way to go >for that. With 28KW of core (not all of the upper card can be used >due to the I/O page, you don't have a lot of OS options. 2BSD is >out, as are recent versions of RSTS and RSX-11. Don't remember what >the requirements for older OSes are off the top of my head. > > > As far as media devices, I have 3 x RK05, 1 x TS03, 2 x RX01, 1 x TU58. > >Nice assortment. Have you checked any of your diskettes or disk packs >for labels that suggest they might be bootable? Both systems have RK05J disks in addition to the three RK05 drives. I presume the disk packs contained within the RK05J drives are most certainly bootable, but I have no idea how they were generated, etc. The drives and disk packs are dusty and I am learning what I need to do and at the same time, not destroy the hardware along the way! I have read the recent thread on cleaning RK05 and disk packs and I will be attempting this. If I get the RK05J disk cleaned and ready to go, and toggle in the bootstrap and the disk loads, do I need to manually start the O/S at some location? I believe the M873YA Bootstram ROM is capable of booting the RK05, but I don't know what would need to be done next (I believe 773010 will boot the RK05) > > I am trying to decide what will be moved to the PDP-11/10 from the >11/20. > > The goal is to have the PDP-11/20 up and running. Getting the PDP-11/10 > > is just a step along the way. > >Are you trying to get something historically accurate or just something >runnning well enough to be interesting? How much core do you have in >your 11/20? That might help drive the answer. If you want to run RT-11, >you'll need a storage device on the 11/20. It could be the RX01. If >you want to toggle in a long bootstrap, it could be the TU-58 (but floppies >are easier to find than TU-58 cartridges, and can be reformatted for the >RX01 with an 8" drive and modern to semi-modern computers). > >-ethan I want the PDP-11/20 to eventually be historically correct but with a full load of options :-) The ultimate goal is to run adventure and Star Trek on it using the LA36 terminal. ie. the quintessential time-wasting use of a mini-computer ;-) Of course the blinkenlights and tape operating has to be part of it too! It is interesting that my 10 year-old son asks to play Star Trek on my MicroPDP-11 rather than the full-motion flight simulator on the PC. _________________________________________________________________ Help STOP SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail

23 years

Just for the sake of asking... (was - RE: Trivia Question)

by Edward.Tillman＠valero.com

Just for the sake of asking: What is a "real computer?" What are its power requirements? What are Its space requirements? What is its storage capacity? How? How many calculations per second? What I/O processes? What I/O media? Y'see... I once met a "real computer" -- I think, and used the darned thing for over two years. It was in a big concrete building, way up north (almost to Santa Claus). It occupied the entire basement of a large, windowless, cubical concrete building, and generated enough heat to warm the whole place during some pretty harsh winters. Its power requirements on a day-to-day basis kinda rivalled Spokane... Its base mainframe measured 60' x 120', had 30 dumb-terminal workstations in its ops center, serviced 120 remote terminals in the building, networked 35 outlying remote stations, but could boast only 1MB of memory, and could handle maybe 3000 calculations per second while in pre-emptive time-sharing. It was idiosyncratic: Though end users tended to interact with it via attached light pens and keyboards, it also had some of the very first "touch" screens -- it only gave up the time-slice when it wanted to... You talked to it through both mag tapes and punch cards. If you fed it a nice, neat stack of punch cards, it literally vomited "hash" back at you. If you attempted the same program with 18" 'high-speed' reel-to-reel mag tapes, it fed you back spaghetti. There was often electrical arcing between user screens and light pens, and I hate to think of the number of monitor screens replaced on the 'touch screens' when some user thought calibration, or 'a little harder' meant putting a knuckle or two through the screen... And we won't even go into the horrid monsters at the end of each corridor know as "batch printers..." It that a "real computer?" > -----Original Message----- > From: cctalk-admin@classiccmp.org@PEUSA On Behalf Of > vance(a)neurotica.com > Sent: Friday, February 21, 2003 5:42 PM > To: Philip Pemberton > Cc: cctalk(a)classiccmp.org > Subject: Re: Trivia Question > > On Fri, 21 Feb 2003, Philip Pemberton wrote: > > > Eric Smith wrote: > > > That's quite a sad definition of "real computer". Any one of my > > > PDP-8 or PDP-11 systems, even the wimpiest, is much more of a "real > > > computer" than any PC compatible will ever be. > > > > What, even if said PC is a K6-II/400 running Linux? I've got two PCs > running > > A PC running Linux is not a real computer. > > Peace... Sridhar [demime 1.01a removed an attachment of type application/ms-tnef]

23 years

QBUS SCSI controller for RT-11

by stuart＠stuartsjohnsonfamily.net

I noticed an auction on eBay for a KZQSA-SA SCSI controller and I was wondering (silly me) if it could be used with RT-11. I know that RT-11 is much older than this board, but I was hoping someone had written a driver for it. If the KZQSA isn't compatible, I'm open to suggestions as to what SCSI QBUS board to get to use in an 11/53 (similar to the machine described on Johnathan Engdahl's site), and if known, where I might get such, hopefully at a decent price - not $799 like on eBay! Thanks, Stuart Johnson

23 years

Timex/Sinclair 2068

by alhartman＠yahoo.com

> From: "TeoZ" <teoz(a)neo.rr.com> > > Do you still have a 2068 and addons for it? No. Nothing that I'd like to sell... Check www.zebrasystems.com Stewart still has printers, some books and maybe some 2068 software. Otherwise, check eBay and flea markets. Sorry. Regards, Al

23 years

decserver 550 in Kansas City

by pete＠dunnington.u-net.com

On Feb 27, 9:35, McFadden, Mike wrote: > Wandering through the local surplus I found a decserver 550 in a full height > rack. > > It had the following boards in it. > > 4 X CXA16-M M3118 > 1 X M3127 > 1 X KDJ11-SD M7554 > > Bulkheads, power supply, and cables > > I read somewhere that it could be converted to a 11/53 with a minimal > effort. How much trouble? Well, it will never be exactly an 11/53, since it's in the wrong box, but you can make it effectively equivalent. I'd remove the CXA16-M serial multiplexers, which I don't think any normal PDP-11 OSs support, but the DESQA should be OK; it'll look to any OS just like a DELQA. You'll need to change the two boot EPROMs on the KDJ11 board. The standard boot ROMs for a microPDP-11/53 are 23-261E5 and 23-262E5. You might get lucky if you type either of those numbers into Google ;-) -- Pete Peter Turnbull Network Manager University of York

23 years

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test-drb February 2003