test-drb December 2015

test-drb@ccmp.vtda.org

191 participants
268 discussions

Advice and Suggestions for a Debug Feature

by jhfinedp3k＠compsys.to

I have been investigating the possibility of adding an enhanced feature to a debug program. There does not seem to be anything specific about the concept, so it should be applicable to every current CPU in addition to most old CPUs. The current syntax for many debuggers uses the letter "S" along with an optional value to specify a Single Step (or ONE instruction to be executed when the value is omitted) or a number of Single Steps (a number of instructions) equal to the optional value. Of the two different debuggers for the CPU, operating system and code which I use most of the time, both debuggers display the same information for each of the Single Steps, specifically the actual instruction that will executed and the values of the registers immediately before the instruction is executed. So if a total of 5 instructions are executed, the display is updated 5 times. For the debugger that I wish to enhance, the actual syntax is: value1,value2,value3;S and at present, value2 and value3 are ignored. My question concerns using value2 and value3 to specify the limits by which the stack pointer may change, specifically by adding data (also called a push) and subtracting data (also called a pop) to the stack in whatever manner the program uses to alter the value of the stack pointer register, respectively. Note that for many CPUs, adding values (a push) results in the stack pointer becoming numerically smaller (unsigned of course). Internally, the code would handle the actual arithmetic. For example, if the user specifies: 45,4,2;S then: (a) Up to 45 instructions are executed (b) If the stack has 4 or more pushes, instructions stop (c) If the stack has 2 or more pops, instructions stop Additional information: (a) Scroll / NoScroll is enabled, so the user can pause / resume at any time (b) Any single character by the user stops instructions (c) All pushes and pops are noted AFTER the current instruction is executed - which allows subroutine calls to be automatically handled as per the examples Defaults: (a) If no values are supplied (ONLY ";S"), then "1;S" is assumed and ONE instruction is executed (b) The debugger supports <ESC> in place of ";S" which supports Single Stepping with a single key (c) If any value is omitted, that limitation does not apply More Examples: ,,1;S instructions are executed until the code returns from the subroutine - IF the current instruction calls a subroutine ,,1;S instructions are executed until the code returns to the previous subroutine - IF the current instruction does NOT call a subroutine ,,1;S instructions are executed until the code restores the stack pointer - IF the current instruction does a push or creates space on the stack ,1,2;S instructions are executed until the code calls a second subroutine OR the code returns to the previous subroutine - IF the current code calls a subroutine 55,1,1;S 55 instructions are executed OR until the code calls a second subroutine OR the code returns to the current subroutine - IF the current instruction calls a subroutine 55,1,1;S 55 instructions are executed OR until the code calls a subroutine OR the code returns the the previous subroutine - IF the current instruction does NOT call a subroutine Many more examples could be considered, but that seems to be about the concept that I have. Please advise and comment. Please make any suggestions that would be any improvement and, most important, point out any problems that I have not considered. Jerome Fine

8 years, 7 months

Interest level for new PDP-11 indicator panels

by jnc＠mercury.lcs.mit.edu

So I've mention that Dave Bridgham and I are working on a new QBUS board (the 'QSIC', for lack of a more imaginative name) that will emulate a variety of older DEC disk controllers/drives using a micro-controller/FPGA and SD cards. (We currently have one prototype [for Dave] mostly constructed, and another [for me] half-way done.) Since Dave and I are both blinkenlitz addicts, we're doing an indicator panel option, emulating exactly the look of the old DEC indictor panels (4x36 lights, with 'inlays' to customize a panel to particular controller, mounted in a 5-1/4 panel for a 19" rack). (These panels are specific to the QSIC, and don't work with the original controllers.) A QSIC will be able to drive up to 4 (or so) indicator panels - I plan to have 3 on my machine: RK11, RP11, and a fixed-head disk. So I'm trying to get a sense of how much demand there would be for the indicator panel option (for parts ordering; I have a chance to buy some discontinued stuff, and I want to know how much to stock up on). If you would be interested in one or more indicator panels, could you let me know? (Please don't reply to the list, just to me personally.) Thanks. Noel

8 years, 7 months

Accessible Computing (Was "Re: Display-less computing")

by captainkirk359＠gmail.com

On 13 December 2015 at 13:46, Chuck Guzis <cclist at sydex.com> wrote: > At CDC Sunnyvale ops back in the 1970s, we had a blind programmer working. > His job output came as punched cards and he had no problem reading them by > feel. I remember him and his beautiful guide dog. > Hmm, that kinda makes sense. It would be kinda/sorta like braille. (I guess that would also work for punched tape as well.) I couldn't tell you how good it would be though, I might be vision impaired, but not enough that I've learnt braille. I wonder if any minis or mainframes (or micros) could actually produce output as braille... > In the same sort of spirit, I recall that one of the secretaries used a > monitor-cum-camera affair to enlarge her work documents so that she could > read them. > CCTV readers. They're still a thing. The tests and exams centre at my university has a bunch of them (one each per exam room, and a bunch of old analogue ones still sitting about). I find the older analogue ones are better than the newer digital ones. If only because the text zoom is more "fluid" (my preferred size of "embiggened" (what, it's a perfectly cromulent word) text is right between two of the settings on the machines we have which is mildly annoying); they also have less artefacts when using non-standard video modes (reverse video, or high contrast modes). > It's sad that early corporate efforts to accommodate all people, no matter > the impairment, aren't better documented. > I'd buy a book on that in a heartbeat; necause that is very much of interest to myself. I know DEC had their DECtalk speech synthesizers (isn't the eminent Dr. Hawking's voice an old DECtalk?) and they could be connected to serial lines. Regards, Christian -- Christian M. Gauger-Cosgrove STCKON08DS0 Contact information available upon request.

8 years, 7 months

Rectangular holes punched from cards [was RE: Display-less computing]

by RichA＠LivingComputerMuseum.org

From: Fred Cisin Sent: Tuesday, December 15, 2015 9:12 AM > My father claimed that the use of round holes on divergent cards was due > to an attempt by IBM to patent the shape of the hole in the cards. http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/punchcard/ Prior to 1928, the holes in IBM's cards were round, too. The use of round holes by Univac was an avoidance of paying royalties to IBM, which held a patent on 80-column rectangularly punched cards. Rich Rich Alderson Vintage Computing Sr. Systems Engineer Living Computer Museum 2245 1st Avenue S Seattle, WA 98134 mailto:RichA at LivingComputerMuseum.org http://www.LivingComputerMuseum.org/

8 years, 7 months

Mystery IC: Allen Bradley 314B102

by gerardcjat＠free.fr

HI, I would take the bet that this IC is simply a R network, 1 KOhm, 1 resistor "across" ie from pin 1 to opposite pin, from pin 2 to opposite pin, etc .... What about simple and quick Ohmmeter check ?? --- L'absence de virus dans ce courrier ?lectronique a ?t? v?rifi?e par le logiciel antivirus Avast. https://www.avast.com/antivirus

8 years, 7 months

Making a serial board for Briel Altair Micro

by dave＠661.org

After fiddling around with my Briel Altair Micro, I've come to desire more than just the console serial port. To that end, I read up on the 16550A UART, line drivers, line receivers, and schematics for other implementations of serial ports. I came up with this: http://661.org/tmp/altairmicro-serial.pdf How close am I to this design making sense and working? -- David Griffith dave at 661.org A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

8 years, 7 months

PDP 11/05 S vs 11/05 NC

by billdegnan＠gmail.com

Just to change the subject.. There were "S" and an "NC" version of 11/05 high profile system. Why? I am curious if any DEC historians here know the reason for two versions of the same DEC PDP 11/05 *high profile* computer (not talking about the low profile). There are separate manuals for each type. The S seems to be more OEM-ish because it comes in an BA11-K chassis. I am guessing you'd see an 11/05 S as part of a larger system (PDP 10), whereas the NC model would be for a stand alone system. ??? This S's BA11-K chassis was used by other hardware by simply changing the backplane. The "NC" model chassis seems to be specifically for the 11/05 I don't think it appears anywhere else. If anyone is interested to see the different models I have a thread on my site for each type: 11/05 S http://vintagecomputer.net/browse_thread.cfm?id=622 11/05 NC http://vintagecomputer.net/browse_thread.cfm?id=249 ... and then there are the 11/10's.... -- Bill

8 years, 7 months

What did computers without screens do?

by kspt.tor＠gmail.com

On 15 December 2015 at 01:31, Mike <tulsamike3434 at gmail.com> wrote: > > On 12/14/2015 08:21 PM, Chuck Guzis wrote: >> Personally, I think the world is GUI-addicted. >> >> --Chuck >> > Chuck If I may ask... > > > What would you do with a home no screen computer? I mean what could be > done with one that would benefit your work / hobby. I mean NO DISREPECT > by asking this question. I'll jump in here - take the current microcontroller hobby segment. You have PIC, or AVR, or Propeller based setups which is used for all kind of things like programmed robots, model cars, drones and RC planes, home control, model trains, temperature- and humidity controlled garden greenhouses, chicken shed day/night door control, and numerous other uses. These things are computers, a Propeller, for example, is an 8-core 32-bit small computer all in one chip. Usually these things have no screen and no keyboard connected. So you program them by various other means, e.g. through a serial interface. For the programming part of it (or the preparation of what you load via the serial interface, or jtag or e.g. a flash or eeprom chip) you'll need something else, today that's usually a PC, but that's conceptually the same thing as in times past where you used a terminal or some device with a keyboard to prepare punched cards or paper tape.

8 years, 7 months

PDP 11/05 S vs 11/05 NC

by jnc＠mercury.lcs.mit.edu

> From: William Degnan > *why* did they make these two versions of the high-profile 11/05? > What was one used for vs. the other? *Why did DEC do this*? Check the dates on the machines. I'm pretty sure the -NC is the earlier version, with the bespoke H750 power supply (mounted alongside the boards, not at the end of the box as with the BA11-K, the basis for the -S). My guess as to why they upgraded from the -NC to the -S is that the latter used the H765 (plus 'bricks') power supply system, in common with the BA11-K and also the later PDP-11's (40's, 45's, etc). That probably provided a raft of advantages, including i) greater flexibility in the current and voltages being supplied, and ii) commonality with DEC's other machines (i.e. lower unit cost -> great per machine profit margin). The BA11-K based -S also (by being a couple of inches longer, and mounting the power supply off the back) had a couple of inches more width for boards, enough to hold an extra quad system unit. And the H765 may have been technically superior to the H750, too. Noel

8 years, 7 months

Identifying Data General (or DG-related) console/terminal/whatsit?

by grif615＠mindspring.com

"Data General Alumni" ?lots of knowledge there. -------- Original message -------- From: Bruce Ray <Bruce at Wild-Hare.com> Date: 12/13/2015 7:09 PM (GMT-08:00) To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: Identifying Data General (or DG-related) console/terminal/whatsit? Not identifiable as DG product - 3rd-party custom (graphics?) console for client?? (I can't read logo on bottom of console.) NOAA/NWS AFOS system had similar-looking system with interesting trackball/keyboard combination.? Then there was GE Medical... Bruce Wild Hare Computer Systems, Inc. bkr at WildHareComputers.com On 12/13/2015 5:22 PM, Josh Dersch wrote: > Hi all -- > > A friend of mine is investigating picking up some DG hardware, and this > item: > > http://yahozna.dyndns.org/scratch/dg/dg%20console.jpg > > Is included along with the rest of it.? I *know* I've seen something > like this somewhere but I can't find anything now that I need it :). Can > anyone identify this? > > Thanks, > - Josh

8 years, 7 months

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test-drb December 2015