PLATO and Me

Wow, that was a blast from the past!

Mike the Mad Biologist links to “an excellent article about the PLATO computing system”.

I didn’t know all the early history.  My own involvement with PLATO begain in the ’80s when I was an instructor at Control Data Institute in St. Louis.  The courses were basically all PLATO, although the students had some projects to complete as well:  on the tech. side, it was mostly building circuits; on the programming side, students had some programs to write.  The instructors were there mostly to assist with the projects.

We eventually replaced the stand-alone PLATO terminals with CDC-110s which had a CRT terminal with a built-in keyboard and a separate double-sided, double-density eight inch floppy.  In PLATO mode, a Z80 microprocessor in the terminal was the boss, and another Z80 in the floppy drive just did the disk I/O; but it could also run CP/M in which case the Z80 in the floppy drive was in charge and the Z80 in the terminal ran the CP/M BIOS.

They also had a text editor called MINCE which the programming students used to write their programs instead of punching cards.  One of the languages we taught was RPG II which required codes to be “punched” into particular columns, so I wrote an RPG mode for MINCE that expanded tabs to the appropriate columns.

MINCE was written in BDS C, an early (and incomplete) C compiler for CP/M systems; and it came with source listings for much of the editor.  I didn’t know C at the time, so I went to a bookstore to get a book on C; and as luck would have it, the book I selected was the first edition of K&R, so I got off on the right foot. πŸ˜Ž

My first home computer was a CDC-110 with a dual floppy drive and a modem that ran at the phenomenal speed of 1200 baud!  I got all that for half price (around $5k IIRC) because I was a Control Data employee, and I eventually sold it for about what I’d paid for it. πŸ˜Ž

CDC eventually got rid of all the land lines and rotary switches for communicating with the PLATO mainframe in Minneapolis and switched to something called the “shared network” that used satellites.  This had the unfortunate effect of increasing the turn-around time for each keystroke to a large enough fraction of a second for H. sapiens to notice.

To the tune of Alabama Bound (with apologies to Lead Belly):

I’m input/output bound.
I’m input/output bound.
If them bits don’t stop, Babe, and turn around,
I’m input/output bound.

Hey listen all you hackers,
Now don’tcha be like me:
You gotta stick with that old PLATO rotary
And let that shared net be.

I’m input/output bound.
…

Ride Share Services

Returning from my recent trip to Issaquah, WA, I wanted a taxi from the hotel to the Amtrak station in Seattle.  The hotel clerk told me that taxis weren’t vary reliable in Issaquah and called me an Uber instead.  The driver showed up within five minutes or so, and it was less expensive than a taxi would have been; so I guess this old dude needs to get with the program.

I checked out the websites for both Uber and Lyft, and it looks like you can’t use either one except through a cell phone which I find annoying, principally because of the difficulty of typing readable text on the phone’s make-believe keyboard.  I’m also guessing that you can’t pay with a credit card but need to set up some kind of PayPal account or something.

Can anybody suggest any alternatives to Uber and Lyft? Or maybe explain to this old fart why it’s not as difficult as he thinks it is?

Thanks.

Early Planning for my November Trip

I’m starting to think about my November trip to Kailua-Kona on the leeward side of the Big Island. I can’t take Amtrak to Hawaii, of course; but I can ride the train to the west coast and fly from there.

[edited 2023-02-20]

There are five options that I can think of, and I’m strongly gravitating toward my current fantasy.

[another edit on 2023-02-21]

Thanks to commenter, sjdorst, and several folks on the AllAboardRailDiscussion@groups.io list, I’ve found out what the Emery Go-Round is and how it connects the Amtrak station to BART; so I now plan to use that westbound; and if the Zephyr is late enough that I’d miss the last Emery Go-Round bus of the day, I’d still have the taxi as Plan B so it wouldn’t mess up the whole trip.

Eastbound, it doesn’t really work because of the time of day and reduced service on Sundays, so I’m still stuck with a taxi fare of (probably) $120 to $150.

I’ve also decided to spend the night eastbound at the Hyatt House across the tracks from EMY.  It could be close to midnight, or maybe even after, by the time that I can even claim my checked bag and get a taxi; but my body clock will still be on UTC-10, so when I get to the hotel, I’ll probably still have enough presence of mind to get undressed and crawl into bed, and I’ll have more time for a leisurly breakfast in the morning.

I’ll still let it stew for a few weeks just in case I think of anything else I should consider.

I hope this is of interest to folks who might want to plan a trip involving Amtrak and I’m not just boring people with my personal problems.  If there are folks who do find it interesting, all my current travel plans, both actual and tentative, can be found here.

Back to the World

One disadvantage of taking long train trips is that I tend to get disconnected from the news outside the FtB bubble; and I’m still about a week behind in my Pharyngula reading.

I knew from a rail-related e-mail list about the NS derailment and fire in Ohio and the fact that pets, livestock and wildlife seem to be dying from the toxic chemicals; but I turned on the TV this morning and found out about yet another school shooting and known Trumpista, Nikki Haley, running for president.  I haven’t been able to process it all yet.

Issaquah Trip Report, day twelve

day −1
day 0
days 1 and 2
day 3
general remarks about the C++ meetings
days 4 to 6
days 7 and 8
day 9
days 10 and 11

2023-02-14, 06:30:

The Holiday Inn didn’t give me my wakeup call; and when I went to the restaurant for breakfast, I found that they had no printed menu.  Instead, one has to scan a QR code with a cell phone.  A woman came by with a tablet and starting punching stuff in, I guess to get me a menu.  After about three minutes of that, I just got up and left.

I went back to my room and dealt with several days of e-mail messages and did some moderation on the blog, then I checked out.  I decided that I didn’t feel quite up to the walk back to Union Station, so the hotel clerk called me a taxi.

08:30:

After checking in at the Metropolitan Lounge, I went to Sbarro’s which was open for breakfast.  I had scrambled eggs, sausage, potatoes and a really big Sbarro’s breadstick.  Everything was much better than what I could have gotten at McDonald’s just across the hall; but I didn’t finish the potatoes…that was too much.

Back to the Met. Lounge to try to catch up on my FtB reading.  I made it through everything except Pharyngula and stderr, then it was back to Sbarro’s for a really big slice of pizza.

12:00:

So here I sit in the Met. Lounge waiting for them to call train 21, the Texas Eagle.  That’ll probably happen about an hour from now, or maybe a little later.

As I said in the previous post, I switched today’s ticket from train 319 to train 21, principally for checked baggage service; but it’ll also be comfortable to ride in the sleeper.  I have room 13, a roomette on the lower level of the double-decker Superliner cars.

13:20:

They called boarding for train 21, and I decided to avail myself of redcap service.

We departed right on time…actually a couple of minutes early by my watch.  I guess it’s OK to do that at big stations once the boarding gates have been closed and there’s no possibility of any passengers arriving at the last minute.

Once we left Amtrak property, we were on Canadian National track; and it’s typical for there to be lots of delays.  As expected, we got several red signals due to freight trains crossing in front of us.

The TA came by for dinner reservations.  I was surprised to see the “traditional dining” menu like we had on the Builder, and I was hoping that the Eagle was getting with the program.  No such luck…that was a mistake.  He came back with the “contemporary dining” menu (the microwaved stuff), and I ordered the baked ziti and meatballs for the entree and the vanilla pudding for dessert.

14:38:  that last stop waiting for freight trains was a really long one.  We’re just now pulling again and we’re only a little way past Summit.  We should be departing Joliet about now.

We mostly maintained track speed all the way to Joliet except for one slowdown, but that was just to get some instructions from the dispatcher.  It sounded like permission to pass a red flag or red signal, but they didn’t go through the whole track warrant business.  Maybe it was something else, or maybe the CN’s rules are more lax in this area.

We stayed about twenty minutes late all the way to just outside of Springfield where we had to stop and wait for train 318 to depart the station.  Amtrak’s status page says that 318 was indeed delayed, but that it had arrived at 17:11 which is just when we stopped to wait for it; so this might not take too long.

17:20:  here we go.

My 17:30 dinner reservation was called shortly thereafter.  Yes, the Texas Eagle does indeed still have a “cross country café” rather than a proper diner.  The baked ziti and the vanilla pudding were OK but nothing to write home (or blog) about.  It also came with a salad, and for dressing I had my choice of ranch and ranch.  I passed.

We actually arrived in Springfield at 17:25, and it’s raining pretty hard.  Amazingly, we departed at 17:27…only two minutes of dwell time.  I guess the passengers didn’t feel the need to dawdle in the rain.

17:56:  we hand another stop due to freight trains in the way, but we’re moving again.  We departed Carlinville at 18:11, now :33 late.

This train has no sightseer lounge with a café in the lower level, so they’re using for a “café car” the end of the “cross country café” closest to the coaches.  We have only one SA (I guess somebody called out), so the “café car”, the only food source for passengers in the coaches, is closed while serving passengers in the sleeper.  It seems to me that that just shouldn’t happen.

We stayed about half an hour late through Alton, then thanks to schedule padding, we arrived in St. Louis at 19:19, just six minutes late.

It took ten or fifteen minutes after the checked baggage arrived in the baggage room for the station agent to finally deign to open up and give passengers their bags.

My car was right where I left it in the long term parking (no surprise), and since it had been raining earlier and the streets were wet, and I hadn’t driven a car in a couple of weeks, I decided to drive home on city streets instead of tooling down the interstate highway.

All in all, this was a very pleasant trip for me, although I’m glad I didn’t have a coach ticket on the Eagle.  Yeah, we were hours late into Seattle, but I had planned for that so it didn’t mess up the whole trip.

My next trip will be early in April when I’ll take a round trip ride on the Texas Eagle to Forth Worth.  I’ll be attending the Southwestern Rail Converence 2023 in Hurst, TX, about a ten or fifteen minute taxi ride from the Forth Worth station.  What would folks like to read about?  More geeky train stuff?  More personal impressions?  Please do give this newbie blogger a hint about anything he’s doing wrong. πŸ˜Ž

Issaquah Trip Report, days ten and eleven

day −1
day 0
days 1 and 2
day 3
general remarks about the meetings
days 4 to 6
days 7 and 8
day 9

2023-02-12 00:37-8:00

I stayed up to watch the switching moves in Spokane (because I’m a grain geek).

Train 8 from Seattle arrived first, and 28 from Portland pulled in behind it.  After detraining the passengers bound for Spokane, 8 pulled forward and switched to another track where it was out of the way; then 28’s engine pulled ahead out of the way.  8 shoved back and tied on to 28, and 28’s engine shoved back and tied on to the combined train.  We now have Siemens 313 in the lead and GE 77 second.

Once we had the full train put together, they boarded the passengers getting on in Spokane.

We got under way at 01:24, only nine minutes late which, on Amtrak, approaches zero. πŸ˜Ž

06:30-7:00:

We’re on mountain time now.

Amazingly, we stayed on time all day, even waiting for departure times at several stations.  The only operational thing that surprised me is that we didn’t make the usual fuel stop in the yard just east of Havre.

The fellow who shared my table for supper in the diner was another programmer.  We had fun commiserating about the sorry state of code these days. πŸ˜Ž

ca. 21:00-6:00:  We arrived in Minot almost an hour early, so we’ll be here for a while.  The engines were refueled from a fuel truck, so I guess that’s the new thing rather than making the fuel stop in Havre eastbound.

2023-02-13:

We departed St. Paul on time at 08:50, but then we were stopped for a while because of a freight train in the way.  Me’re moving again at 09:05.

We stayed between ten and twenty minutes late all the way through La Crosse; but that can change on the SOO Line through Wisconsin to Milwaukee.  We’ll see…

Nope, no problems there.  We departed Milwaukee at 15:12, only seven minutes late.  We might even be early into Chicago thanks to schedule padding.

16:02:  oops, I knew it couldn’t last…emergency brake application…the conductor made an announcement on the PA saying that “a brake hose came apart” and he would have to “put it together again”.  Let’s hope that’s all it is.

16:10:  that wasn’t bad…we’re pulling again.

I heard on my scanner the engineer informing the dispatcher that “everything’s independent”.  I’m guessing that that means that they’re using the independent brakes, air brakes that apply only the engine’s brakes, to pressurize the regular train line, the brakes on all the cars.  I suppose that’s OK as a temporary fix since we’re less than one hour from our final stop.

<aside>
For non-train geeks, the way air brakes on trains work is that air pressure in the brake line holds the brakes off, and brakes are applied by reducing the pressure.  That’s why anything that dumps the brake line quickly, like parting of the line for any reason, applies all the train’s brakes as hard as possible.  That’s the “emergency brake application”, and it can cause a derailment because of later cars that haven’t had their brakes applied yet ramming into earlier cars that have.  (The “signal” that applies the brakes is an air pressure wave that travels through the brake line somewhat slower than the speed of sound, and freight trains can be miles long these days.)  That’s usually not a problem for passenger trains which, aside from being much shorter, have couplers that don’t give as much; but conductors still have to walk the train to look for any problems that might have been caused.
</aside>

We made our final stop in Chicago at 16:53, only eight minutes late.  For some reason, they spotted the engines four or five car lengths north of the entrance to the north boarding lounge, so even folks in the Seattle sleeper, the first revenue car on the train, still had an extra city block to walk.  It seems to me that there was no reason for that.

This was a most enjoyable trip on the Empire Builder, in large part because of the crew who had been working together for over a decade and liked each other, and also liked their jobs.  A happy crew makes for happy passengers.  I hope I left big tips all around.

On arrival in Chicago, I made a bee line to the Amtrak ticket counter and changed tomorrow’s final leg to St. Louis from business class on train 319, one of the “Lincoln Service” corridor trains, to a roomette on train 21, the Texas Eagle, and then promptly checked the bag that I had just claimed off train 8.  (The corridor trains have no checked baggage service.)  This old back will no doubt appreciate my not having to deal with it until I get home.

My back also appreciated taking a taxi to my hotel rather than walking the three blocks to the Holiday Inn just south of the station.  The taxi fare was just about five bucks, so I gave the driver another fiver as a tip for getting stuck with my short fare.  I’ll probably do the three block walk tomorrow morning since I’ll be rested and ready to go.

This hotel has been completely renovated, and the restaurant won’t be ready for supper until next month, so I just had some junk food.  I didn’t want to go out anywhere for supper.  Instead, I wanted to get to my room so that I could get these blog posts back in sync. πŸ˜Ž  I was assured that the restaurant will be open for breakfast in the morning.

I’ve also added a link to the group photo that I mentioned in the days 7 and 8 post.  These are most of the folks with whom I have the pleasure of being associated in my small way.

Issaquah Trip Report, day nine

day −1
day 0
days 1 and 2
day 3
general remarks about the meetings
days 4 to 6
days 7 and 8

2023-02-11 08:30-8:00:

Today begins my trip home, but that won’t start until this afternoon.  This morning is the final half day of the C++ standards committee, a plenary session where we take formal votes and wrap things up.

I lost a pair of glasses somewhere yesterday.  I was hoping that somebody would find them and turn them in, either to the front desk at the hotel or to one of the folks in charge of the meeting…no such luck.  Fortunately, what I lost are my “computer glasses” with the same prescription as the near prescription on my bifocals; and I can see my computer screen just fine as long as I’m only about a cubit from it.  I think I need to get some new glasses anyway because my eyes seem to be getting worse.

10:00:
Well, that was fast.  We finished our work and took the 32 formal votes in just an hour and a half.

The next two meetings will be in June in Varna, Bulgaria, and in Kona, HI, USA in November.  I’ll take Amtrak to the east and west coasts, respectively, and fly from there.

We have 2024 meetings tentatively scheduled for Japan, Sweden and Poland.  I’ll probably participate in the Japan meeting via Zoom since I refuse to sit in an airplane long enough to get there in person.

The hotel had no way to call me a taxi, but the very nice woman at the front desk called an Uber using her app; and I paid her the cash.  I have a cell phone, but I don’t have any special apps on it.  I guess this old dude needs to get with the program.

11:15:

After checking one bag to Chicago at the train station, I went to a restaurant in the Embassy Suites and had the Reuben sandwich.  It was edible, but I could detect no 1000 island dressing.  I guess the cook layed on hands and intoned “1000 island”.

12:00:

King Street Station has no place to sit at a table and work on a laptop; but on the third floor is some kind of arts and education council office, or something, which has a couple of such places; so here I sit, one of three folks doing a bit of writing.

Train 8 started boarding about 16:40 or so and departed on time.  I’m in room D this time, so the electrical outlet is near the window where I’ll be plugging in my power strip.  I’m riding backwards this time, but that doesn’t bother me, and I’m on the fireman’s side eastbound so I won’t have the sun in my eyes going through big sky country.

Like the westbound trip on train 7, this train has only one coach.  The TA said that it’s OK during the light travel season, but they’ll really need a second coach, and probably a second revenue sleeper, before long.

We were out of Wenatchee only about fifteen minutes late.  It turns out that Wenatchee is a crew change point for the engineers, but not for the conductors.  Normally, engineers and conductors work, not particular trains, but particular sections of track.  Why only the engineers change in Wenatchee I have no clue.

We have about a two hour dwell time in Minot, which I’ll talk more about tomorrow.  For now, I’ll try to use this time to post the report for day 9.  It might not be proofread as well as it should have been.

Issaquah Trip Report, days seven and eight

general remarks about the meetings
days 4 to 6

2023-02-09:

I didn’t get a good night’s sleep last night and felt pretty wiped out most of the day.  I spent a little time in the Evolution Working Group (EWG), the subgroup that considers changes to the core language.  All I remember is something called a “pipeline operator” which would inject arguments into following function calls.  I couldn’t figure out what it was good for or why anyone would want it.

Mostly I rested up for an evening session of the numerics study group where we continued the discussion of floating point rounding that slopped over from the evening session on Tuesday.  It turns out that there are quite a few cases where the behavior is not at all intuitive.

The last thing on the agenda was a paper of mine.  About a decade ago or so, I had in mind a database access library in C++ that would be the rough moral equivalent of the java.sql.stuff; but I soon had some medical issues and couldn’t pursue it, and so nothing ever came of it.

One thing I needed, and implemented, was a C++ type that could give me a round trip to and from SQL’s NUMERIC and DECIMAL types which are fixed point decimals.  A few years ago, the numerics folks were thinking about publishing a numbers TS.  The rational number in §7 of that paper was my work; and I thought that my “big decimal” type was a kind of number, too, and so maybe a more generally useful version of it (written against C++23, has NaNs and infinities, etc.) could also go into the TS.  It turns out that there’s not much interest in that any more, so I won’t be pursuing that any further.  I think that was the right decision since my target audience is good old “business data processing” which isn’t really the market for C++.

2023-02-10:

I spent today in EWG where it was “safety Friday”.  We spent the morning talking about various ways to mitigate the problem of uninitialized local variables on a function’s call stack.  There seems to be consensus for the rule that local variables without explicit initializers should be zero-initialized (like globals are), but it turns out that there are corner cases where that could change the meaning of some code, and static analysis tools would no longer be able to flag the potential bug.  We’ll need to think about this some more.

Just before lunch, we took the customary group photo.  As I write this, it’s not online yet; but I’ll embed it when it is.  I’ll be which is the bottom picture among these three.  I’m the old fart on the right of the first row who’s sitting on his walker wearing a St. Louis Cardinals baseball cap and an N95 mask (because COVID isn’t over yet).

After lunch, we talked about “type and resource safety”.  From the paper by Bjarne Stroustrup:

  • every object is accessed according to the type with which it was defined
  • every object is properly constructed and destroyed
  • every pointer either points to a valid object or is the nullptr
  • every reference through a pointer is not through the nullptr
  • every access through a subscripted pointer is in-range

Those are informal rules that C++ coders have always been expected to follow, but it’s not really possible for static analysis tools to enforce them completely.  There seems to be a strong consensus for some kind of framework that would improve the situation.

Tomorrow morning will be a plenary session where we take formal votes.  That should end by noon, probably before; and then I’ll be on my way back to King Street Station where I’ll board Amtrak’s Empire Builder for the first leg home.

Issaquah Trip Report, days four to six

general remarks about the meetings

First, a caveat emptor:  the Hilton Garden Inn in Issaquah, Washington lacks a proper restaurant.  Instead, they have a bar that has limited menus for breakfast and supper…no lunch at all.  Also, they don’t send out laundry or dry cleaning, so I’ll be a mess on my trip home (not dirty or smelly, but definitely unpressed).

2023-02-06:
The plenary session where we took care of administrivia only lasted until the morning break.

For the rest of the day, I hung out in the Library Evolution Working Group (LEWG) where we dealt with eleven papers.  Four answered national body comments, one fixed a bug (for which there was no NB comment), and one answered a comment from the Core (language) Working Group (CWG).  That completed our high priority business, so the other five papers were suggestions for new standard library features.  We’ll be talking mostly about new features for the rest of the week since that’s what LEWG is about anyway.

2023-02-07:
This old dude was happy to catch up on his sleep and write the blog post I linked to above.  I’m pretty sure that nobody on the committee missed me. πŸ˜Ž

The hotel doesn’t have all the meeting rooms that we need, so some groups have evening sessions.  I attended an evening session of the Numerics Study Group where we considered three papers, one suggesting additional statistics functions, one about an extension to the random number business, and one claiming that more math functions could be declared constexpr (“constant expression”).  There was a fourth paper that dealt with deprecating and replacing the fsetround and fgetround functions in the floating point environment that C++ inherits from C.  We got through the rationale for deprecating the functions, but we ran out of time before we could talk about what to replace them with.  We’ll have another evening session on Thursday when, if we have the time, we might also talk about my paper.  (The floating point stuff is very much more important.)

2023-02-08:
LEWG spent the whole day talking about SIMD stuff (“single instruction, multiple data”).

<aside>
The committee can publish three kinds of documents, an international standard (IS), a technical specification (TS) which is a kind of warning about possible future standardization (“Hey, vendors and users, try this out and let us know if we made any mistakes.”), and a technical report (TR) which is basically “Here’s something we thought you might find interesting.”
</aside>

We have a TS that defines a class called simd that provides a mechanism for doing parallel processing of vectorizable data on multicore machines, which is a Really Big Deal for the numerics folks.  As expected, “mistakes were made;” and fixing them has lots of subtle ramifications.  This took lots of discussion among numerics experts, most of which went over my head.  (One of the reasons that I participate in the committee is that I can learn lots of stuff just by keeping my mouth shut and my ears open.  I hope I never stop learning.)