Domain: pdp8.net
Stories and comments across the archive that link to pdp8.net.
Comments · 21
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Re:PDP 8 field service school, at "the mill"
PDP 11/35.. Assembly using an op code booklet and entering it directly in core memory with toggle switched color coded in groups of three for easy octal entry. 32K of 16 bit core plane memory. About a year later we added an RK05 hard disk..
You think a 32G thumb drive is expensive? You should figure the cost per Gig for RK05 platters!
http://www.pdp8.net/rk05/rk05.shtmlDrive and controller $7900 and $350 installation from DEC in 1974
74 Dollars per month for maintenance
Additional drives $5100 and $260 installation
64 Dollars per month for maintenance
Disk cartridge $99About 0.002 GB of data
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How is this a laptop?
Aren't they stretching things calling this a laptop? Certainly its portable but it can't be easy to port this. I've had Sun monitors that weighed less than this. No way I'd be putting this on my lap. It isn't battery powered either. Some additional information is at this site with some additional information and pictures - http://www.pdp8.net/asr33/asr33.shtml
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Re:Editors...
They were using "smiley" face symbols long before we used them on computers. "Teletype" - used these many many years before the 1980s.
What are you wittering on about? Teletypes are computer terminals. Computers did exist before the 1980s, you know. I can assure you that, when I used Teletypes connected to minicomputers in the 1970s, nobody used the
:-) smiley face. Perhaps it hadn't been invented yet... -
Re:Editors...
They were using "smiley" face symbols long before we used them on computers. "Teletype" - used these many many years before the 1980s.
What are you wittering on about? Teletypes are computer terminals. Computers did exist before the 1980s, you know. I can assure you that, when I used Teletypes connected to minicomputers in the 1970s, nobody used the
:-) smiley face. Perhaps it hadn't been invented yet... -
Re:movie
But you can't do that with a Teletype...
On the other hand, the first computer "animation" I ever saw was on the VDU attached to my school's PDP-8/e: by outputting an I, then backspacing and overwriting it with an O, then repeating, it gave the impression of a spinning disk
:-) -
Re:Amazing!
I'm 34.
I've got almost a 20 year headstart.
Just for grins, what size was the WD drive that failed?
3.2GB. This was back in 1997.
My 30 Gig failed in 2003. The 5 Meg drive failed in 1978. The 5 Meg drive cost more than your computer system unless you have a real spendy system.
http://www.pdp8.net/rk05/rk05.shtml?med -
They blue it!
It's supposed to be green (and white). And what's with that skinny little line? The bar is supposed to be half inch allowing for 3 lines of (132 char) text per bar .
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Re:I find this hard to believe
Scrolling as a term for moving a display predates video games -- it was used in computing while paper teletypes were the most common sort of terminal. An example is here: http://www.pdp8.net/editors/scroll/scroll.shtml
Note that I'm not referring to the name of the editor being described, but the fact that the term "scrolling" is used several times without first defining it, thereby indicating that the audience for the document were expected to know what it meant.
I am thus pretty sure therefore that most game developers knew what scrolling was before a gaming mag writer did the world a favour and invented it. -
Re:How about...
I too started out (at school) on a PDP-8/e with paper tape and teletypes and you are correct - it and the PDP-11 were minicomputers. Witness the fact that rather than containing a microprocessor they had multiple-board processors: "The first 6 cards is the CPU". (Don't blame me for the grammar, folks; I'm quoting.)
DEC did produce a PDP-11-on-a-chip called the T-11. For a while in the mid-80s I had a system based on it, which a friend who had a combination of too much scrap hardware and too much free time put together for me, together with a VT-05 terminal. Eventually he replaced it with his PDP 11/34, once he'd found himself a VAX...
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Re:How about...
I don't know if the PDP-8 and 11 qualify as microcomputers; I always thought they were minis, but they sure were great boxes.
Cut my teeth on a PDP-8/E (http://www.pdp8.net/) running ETOS (a 16-user timesharing OS) in 64KB of memory. It had a great, powerful, simple assembler language. I remember the day we got a 1MB hard disk -- wow what an upgrade from (small) mag-tapes and paper-tape!
The PDP-8 would be a good box to play with too. It's fairly simple inside (AFAIR); and not too large. You wouldn't need a hard disk to run it, especially not for an exhibit. Just use the small mag tapes.
Plus it will really look good in an exhibit, better than the later micros. It's got a good set of blinking lights on the front (and LED numbers too, depending on the model), which always looks more impressive in an exhibit. And you could set it up to spin the tape reels back and forth too, which looks good.
If you're really ambitious, there were some assembler programs that controlled CPU in a way that its electrical interference would play music over nearby radios. Now that would be a cool exhibit - blink lights and LEDs, tape drive moving back and forth, and music playing over an old transistor radio nearby! -
Re:Wow!
Floppy disks have an interesting history that goes back even further than the 80's. They were clunky and slow, but they did provide a reasonable alternative to something like this removable cartridge hard drive of the same era, especially when compared to punched paper tape or audio cassette.
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Re:What kind of video card?
I was also looking for an 8" drive for my one 8" floppy (which probably no longer has useful data anyway), but they seem to have all disappeared / broken.
I wanted a cassette deck, but couldn't justify the cost. -
Re:DirecTV
No. But of course if you can handle something like MythTV....
I had mine recording off an old directv box, but you have to rig up a serial cable from the computer to the box to change channels.
http://www.pdp8.net/directv/directv.shtml
You could probably do something similar with an IR transmitter also. -
Re:Mod Parent(s) Up!
Behave yourself, or I'll come round your house,
delete all your editors, and install TECO.
Then you'll have something to complain about. -
Re:So what really do we have here?
Wasn't the PDP-8 one for the first minis? I knew Apple had stolen their idea from somewhere!
In fact if you compare this picture with this picture you'll see exactly what I mean. Clearly, Apple is ripping of DEC. =) -
ideas and problemsIf you want to convert an old electric typewriter into a USB input/output device you will face a few challenges.
First, traditional electric typewriters were mostly mechanical beasts (electric, not electronic) actauted by springs and levers with the user's finger motion enhanced by a flywheel. Only the flywheel was driven electrically, all the rest was mechanical. This means that there are no electical siganls generated when the user presses a key, just a series of levers and catches that connect the flywheel with a typearm and some mechanism to advance the carriage. Even the carriage return and platen advance was mechanical: as the carriage advanced a spring was stretched. The carriage return released the carriage, which was pulled rapidly to the right by the carriage return spring. When the carriage slams into the stop at the rightmost end of travel, a pin or wedge caused the platen to advance to the next line. The driving force for the platen advance was the momentum of the returning carriage.
In theory, you could instrument the typewriters mechanics with sensors to detect key presses and carriage return events using optical or electronic sensors. The sensor states would be fed into a microcontroller which would format them for communication over the USB port. This would allow you to use the typewriter as an input device.
Using the typewriter as an ouput device, however, is more complicated. You would actually have to add a bunch of actuators (solenoids, for example) to the typewriter's mechanism. I can think of a few ways to do this, but they are all labor intensive (I'd mount the solenoids vertically beneath the typewriter and connect each solenoid to the actual key it drives by a wire or shaft. When the soleniod is activated, the key is physically pulled down, just as if the key had been pressed normally.) and power hungry. Again, a microcontroller would be used to accept data from the USB port and translate it into signals to actuate the solenoids. The MCU would need to keep track of, or be able to sense, carriage position and put suitable delays between keystrokes to prevent jamming the device.
It all sound quite fascinating, but of very little practical value. It is likely to be a bit costly as well, but that shouldn't stop the dedicated hobbyist. Of course, for a lot less effort and money you may still be able to find an old ASR-33 teletype with an optional RS232 interface (most ASR-33's used current-loop interfaces, which are not directly compatible with RS232). These old teletypes are pretty much what you are looking for, ready-made. You may freely substitute a DECwriter for the ASR-33 and I think there may be some versions of the IBM selectric that also fit the bill.
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Re:Not 5.25 inches tall?
Depends on how old-school your computer is...
l8 inches could be a possibility :-) -
Those impertinent whippersnappers...Old enough to drink...BAH!
How about old enough to run for President?
:-D -
Re:Might you be able to help me?Ha indeed! Yours is only 5-6 inches? Mine's a full *8* inches - and that's just the diameter. Heh.
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Re:Might you be able to help me?Ha indeed! Yours is only 5-6 inches? Mine's a full *8* inches - and that's just the diameter. Heh.
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Re:HUNT THE WUMPUS
I loved that game--i think it was origionally for the TI-99/4A
Wumpus certainly predates the TI-99 systems, and I think it predates microcomputers in general. Here is a page showing the instructions for a PDP-8 version. Note the stylish usage of ALL CAPS, for those people who couldn't afford lower case.
A quick bout of Google will yield any number of web-based Wumpus Hunts, and surely the source code is out there somewhere.
Shameful confession: my first Visual BASIC program was Hunt the Wumpus.