Terminal Emulation

I run RSTS/E V7.0-07 on an emulated PDP 11/70. This is kind of cool, but would be useless without someway to access it. Best option would be an actual terminal, but for me they are too hard or too expensive to come by.

That leaves me with some sort of terminal emulation. Terminals on the 11/70 that I used in school tended to fall into two groups, paper and video. The video terminal screens of that time were close to being square and used a monospaced font (all the letters were the same size). The ones that I used VT52 and similar used a display of 80 columns and 24 lines. More modern computers use a more rectangular screen with fonts that are not monospaced and can (and do) change size.

For terminal emulation I have a choice of Windows (7, 8.1 and 10), android, Macintosh (6.0.8) and Apple II. I’ve tried several terminal emulator programs under Windows and they all have what I consider a drawback. An 80×24 screen is slightly bigger than a 4×6 index card. I still use both Putty and Tera Term on occasion but if I want to do anything serious I would prefer another option.

I haven’t ruled out the Macintosh, but as of yet I haven’t found a terminal program I would use on a regular basis.

That brings me to the Apple II. My first Apple II was an Apple //c with a 9″ monochrome monitor. About 10 years ago I was looking at some Apple IIs on eBay and saw one where the seller had it hooked up to an LCD monitor with great results. I sent a note to the seller telling him I wasn’t interested in the Apple II so much as what monitor he was using. He was very understanding and told me it was a Dell 2001fp. I bought one of those and shared it with my PC. It takes Composite, VGA, DVI and S-Video inputs and you can change with a push of a button on the front. This is what I use on my Apple //c now. It is a 20″ monitor, which after a 9″ monitor is pretty nice and is also more square (4:3) than the current monitors.

My Apple //c is connected by a serial/null modem cable to the PC that runs my emulated PDP 11/70. I use ZLink as terminal emulation software on the Apple //c and works very well for my purposes.

I uploaded a video of using the Apple //c and Dell 2001fp Monitor as an emulated terminal to YouTube at : https://youtu.be/y0Aok67byXk

Oregon Trail, Update and Online

Last July, I posted about finding a copy of an early version of Oregon Trail.  I was going to get it running on an emulated PDP 11/70 running RSTS/E.  I managed to get it all typed into the emulated computer, but it was not running very well.

Recently, I cleaned up my ability to print listings from my emulated PDP 11/70.  One of the listings I printed right away was for Oregon Trail.

Last night, I spent about half the night working on Oregon Trail.  I loaded up the PDF of Oregon Trail in Creative Computing (V4N3 May/June 1978) and set the size at 200%.  Working with the printed listing and a ruler to mark my place, I went line by line through the program and made corrections on the printout.  In some instances I increased the size setting to as high as 1600% in order to clarify what was in the magazine.  I spent a matter of a few minutes making changes from the listing to the program and as a finale step ran a cross reference listing and found one variable that was not really supposed to be there.

I believe I have it running now and have put it in the games library so others my try it out.


Creating PDF of Basic-Plus listings using WF-2630

In the past I have tried to get usable listings posted in blog postings and they don’t fare well for me anyways.  While I was working on getting my emulated 11/70 to print I tried out something that works out pretty cool.

I have an Epson WF-2630 multifunction printer.  It prints, scans, and faxes.  It can create PDF documents as it scans and has an Automatic Document Feeder (ADF).

When you print out a listing it stacks up first page on the bottom to last page on top, so first thing I did after printing a listing is to reverse it so the header page is on top of the pile.

After I looked at the first couple of listings I had a thought about creating a PDF of one.  I took the stack and put in the ADF of the printer facing up.  I ran the Epson scan program and just told it to scan using the ADF.  For the size setting I used “Letter [L][11 x 8.5 in.]”.  After scanning the whole document I saved it.

The first couple of times I tried it I was using the size setting of “Letter [8.5 x 11 in.]” and then when I opened it using Adobe Reader I would rotate the image.

Choosing the “Letter [L][11 x 8.5 in.]” setting saves me from having to rotate the document to view it.

Looking at the PDF this creates is very much like looking through an old fanfold listing.

Here is a listing of a program I typed in called Star Merchant:

Emulated 11/70 Printer

I have emulated a PDP 11/70 to run RSTS/E for decades.  The big thing that was missing for me was the ability to print.  Almost two years ago I switched from SimH, a great emulator, to Ersatz 11.  Ersatz 11 has the ability to print using the host computers printer.

When I switched over I got the printer working but, it wasn’t quite right  I seemed to loose a few lines of text over the page breaks.  The other night I had time to sit down and work though it.

If I print the traditional way, I could only get 80 columns.  Ersatz allows you to rotate the output to get wider printouts.  I had already rotated the output, but while I got the wider printouts I was loosing a couple of lines across the page breaks.  A little tedious trial and error resulted in a setting I could work with.  This line in the ersatz init file sets up the printer:  ASSIGN LP0: OSPRINT: /LANDSCAPE/ROTATE:90/FORM:LETTER/SIZE:132×58

Once RSTS/E was setup I changed the spool command file


You will notice that the init file defines a page size of 58 lines of 132 characters, but the spool file defines it as 55 lines of 132 characters.  They don’t match but they do work on my Epson WF-2630.

The print out is not perfect.  The header pages from QUE are a few lines to long to fit on a page but the rest of the print out is great.



RC2018/04 – April 30

The month has run out.  My project is nowhere near done.  It is in fact barely started.

I have been working on initializing the files.  Seems like every time I made a step forward, I trip over something.  I’ve been working with three manuals in PDF format and a large paperbound book.

It took me days to figure out why I was getting a Protection Violation.  It turns out I was over thinking opening the file and added an unnecessary mode.

Now I’m dealing with a bloated file.  It should be a block in length and yet it exploded up to sixteen blocks.  The record size of the file should mean I could get 16 records in a block.

While RC2018/04 is over, my project is not done, but I plan to keep plugging away on it!




RC2018/04 – April 1

Once again it’s that time of year, RetroChallange.  Last year I choose a similar project and you can see that down below at RC2017/04 – April 1.  I never got one line of code written.

For this RetroChallenge I plan to write a multiplayer game that will run on an emulated PDP 11/70.  I’m leaning towards a multi-user dungeon.  I once used one that allowed users to add on and that seemed pretty cool.

I’m working along the same lines as last year, in that I want others to be able to play along as it were.  A little later on, as I get things working, you will be able to telnet to puff dot mooo dot com at port 4000 and sign in.  This year we will use account (18,4) with a password of RC.



Norton, Done and Gone!

Yesterday, we lost power in our area due to lines going down.  Ice, I believe, was the cause.

Anyhow, when power came up Norton did it’s thing and tried to quarantine E11.

I decided I was tired of this game.  I uninstalled Norton and went with different antivirus protection.  I will just have to see how that works.


Last Update 30-Mar-18


Norton Ruins My Day!?!?

Almost a week ago, I sat down to my computer and saw a notice from Norton about a virus.  Norton in its usual fashion took care of it.  It removed the file.

The problem was; and the reason I am writing about it here, is the file it removed was e11.exe.  E11.exe is a program by dbit, Ersatz 11, that emulates the PDP 11.  As I wrote in my last post I have been working on an older version of Oregon Trail on an emulated PDP 11/70.

I downloaded it again and reinstalled it on my hard drive.  Norton once again spoke up and warned about the virus.  I asked it for details and it turns out it was not so much a virus as the file only reported as being used by 50 people, so it must be dangerous.  I told Norton to leave it alone.

I went and started it up, except all was not back to normal.  Instead of starting up my PDP 11 emulation all I got was the prompt for E11.  I exited and did a quick directory; no data files or init files.

My most recent backup was before I started Oregon Trail.

I was pissed.  I am not a typist and only manage about 32 word per minute, so typing in Oregon again was a significant investment of time that I did not want to do.  I took a step back and decided to think about it a couple of days.

During that time I thought of a few changes I would like to make in my emulated system.

Finally, a couple of days ago, I sat down.  I was going to re-setup my emulator.  I went to the directory on my C drive to start and had a flash.

My system, when I had it built, had some unique features.  I installed a small SSD (120GB) for a boot drive.  Added to that, I installed a new 1TB hard drive and another one from my old computer that I was replacing.  Windows went on the SSD (C) and the other software went on the new 1TB hard drive.  That included Ersatz 11.  When I reinstalled it, it went to C instead of where it should have.

I moved E11 from where it was installed to the proper directory and I was back up and running.




Oregon Trail

Oregon trail has been documented historically in other places, but it first came out in 1971 and you accessed it using a teletype.  It went away for a few years and came back under MECC in 1974 and you still accessed by terminal.  I was in school all during the 70’s on the east coast, so I never ran into it.  MECC had it rewritten for the Apple II and released in 1985.

I got my first Apple computer at the end of 1984, an Apple //c.  Over the years, I kept an interest in the Apple II world and still have my original Apple //c.  It doesn’t work and have replaced it with a slightly newer version but, still hope to get it repaired.

I never heard of Oregon Trail until maybe twenty years later.  I’ve since then played the Apple II version using AppleWin and realized that it is exactly the kind of game I would have spent hours playing in school.  Of course, had I played it in school, it would have been using a teletype or other terminal, since the Apple II didn’t come out until several years after I finished school.

I was recently reading a history of the game and found a basic listing of one of the earlier versions was published in the May-June 1978 issue of Creative Computing.  I tracked a copy of this issue to Archive.org and printed out the article.  My plan is to enter this game into an emulated PDP 11/70 running RSTS/E and BASIC-PLUS giving it the feel to a certain extent of the original.  You would have to log on using a terminal in order to play the game.