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It's pretty amazing that the display had 1024x1024 and up to 4096x4096 resolution on 5 inch screens in the 60s. They say the 4096x4096 was for photographic rec

It's pretty amazing that the display had 1024x1024 and up to 4096x4096 resolution on 5 inch screens in the 60s. They say the 4096x4096 was for photographic recordings, I wonder if there is any data saved that was displayed at this resolution from the 60s, it seems like each photo would have been huge compared to the size of storage available back then.

masswerk 12y ago
It's really hard to say, but some of the high-res scans of DEC promotional material for the Type 30 CRT (1024 x 1024) at bitsavers.org are showing screenshots with a pretty good quality: http://bitsavers.org/pdf/dec/pdp1/JPEGs/ http://bitsavers.org/pdf/dec/pdp1/JPEGs/ On the other hand the 1024 x 1024 of the standard display was rather a technical resolution, the visual resolution would have been – according to DEC – about the half (since the bleeding phosphor of the activated blips on the screen would overlap and merge). A closeup of the Type 30 CRT displaying an early version of Spacewar! can be seen here: http://www.masswerk.at/spacewar/decus1962/spacewar-decus1962-figure1-large.jpg http://www.masswerk.at/spacewar/decus1962/spacewar-decus1962... On the storage capacity: Please mind that these weren't bitmap driven displays, all the images had to be composed and refreshed algorithmically. On the up-side, this meant that even a small program could display effective graphics, like Snowflake (see: http://www.youtube.com/watch?v=Y1ioLo2I_5Y http://www.youtube.com/watch?v=Y1ioLo2I_5Y) which would only use about 190 instructions or memory locations. Also, consider that these were 18-bit words holding op-codes (6-bit) and addresses (12-bit) in the same instruction word. This was quite more densely packed, like say, in a 8-bit microprocessor computer. For example, I would doubt that (the original) Spacewar! could have been ported to a C64, both for speed and storage, left aside the graphics. (But I could be proven wrong here ... :-))
- swimfar 12y ago
  The screenshots are here (so you don't have to click all 25 images looking for them): http://bitsavers.trailing-edge.com/pdf/dec/pdp1/JPEGs/Type30CRT_Jun64_3.jpg http://bitsavers.trailing-edge.com/pdf/dec/pdp1/JPEGs/Type30... http://bitsavers.trailing-edge.com/pdf/dec/pdp1/JPEGs/Type30CRT_Jun64_4.jpg http://bitsavers.trailing-edge.com/pdf/dec/pdp1/JPEGs/Type30...
  - masswerk 12y ago
    A display similar to the Type 30 CRT can be seen in action in this video of a Bell-Labs educational film: http://www.youtube.com/watch?v=iwVu2BWLZqA http://www.youtube.com/watch?v=iwVu2BWLZqA ("The Incredible Machine", 1968). The video shows later equipment, a PDP-5 and a display that looks like a member of the 330/340-family, but the technology is the same. (Interactive graphics technology like in TX-2 and the PDPs was actually amazing, but apparently got lost over time-sharing ...)
watmough 12y ago
I'm old enough that my first experience of 'big computer' graphics in the mid-Eighties was on one of these: http://www.pdp8.net/tek4010/tek4010.shtml http://www.pdp8.net/tek4010/tek4010.shtml Tektronix 4010 storage tube display. It was actually pretty nice, as long as you just wanted to draw a picture.
sehugg 12y ago
I don't think they saved the photos verbatim -- rather, the idea was to use the CRT to slow-scan the photographs and analyze them by recording the light that transmitted through the film. http://www.computer-history.info/Page4.dir/pages/PDP.1.dir/ http://www.computer-history.info/Page4.dir/pages/PDP.1.dir/
ajross 12y ago
It's not a raster display. The beam is driven by two voltages for X and Y, so really what those numbers are actually saying is that it had a pair of 12 bit DACs (hardly shabby technology in 1961, but not a 4k monitor either).

masswerk 12y ago

It's really hard to say, but some of the high-res scans of DEC promotional material for the Type 30 CRT (1024 x 1024) at bitsavers.org are showing screenshots with a pretty good quality: http://bitsavers.org/pdf/dec/pdp1/JPEGs/ http://bitsavers.org/pdf/dec/pdp1/JPEGs/ On the other hand the 1024 x 1024 of the standard display was rather a technical resolution, the visual resolution would have been – according to DEC – about the half (since the bleeding phosphor of the activated blips on the screen would overlap and merge). A closeup of the Type 30 CRT displaying an early version of Spacewar! can be seen here: http://www.masswerk.at/spacewar/decus1962/spacewar-decus1962-figure1-large.jpg http://www.masswerk.at/spacewar/decus1962/spacewar-decus1962... On the storage capacity: Please mind that these weren't bitmap driven displays, all the images had to be composed and refreshed algorithmically. On the up-side, this meant that even a small program could display effective graphics, like Snowflake (see: http://www.youtube.com/watch?v=Y1ioLo2I_5Y http://www.youtube.com/watch?v=Y1ioLo2I_5Y) which would only use about 190 instructions or memory locations. Also, consider that these were 18-bit words holding op-codes (6-bit) and addresses (12-bit) in the same instruction word. This was quite more densely packed, like say, in a 8-bit microprocessor computer. For example, I would doubt that (the original) Spacewar! could have been ported to a C64, both for speed and storage, left aside the graphics. (But I could be proven wrong here ... :-))

swimfar 12y ago
The screenshots are here (so you don't have to click all 25 images looking for them): http://bitsavers.trailing-edge.com/pdf/dec/pdp1/JPEGs/Type30CRT_Jun64_3.jpg http://bitsavers.trailing-edge.com/pdf/dec/pdp1/JPEGs/Type30... http://bitsavers.trailing-edge.com/pdf/dec/pdp1/JPEGs/Type30CRT_Jun64_4.jpg http://bitsavers.trailing-edge.com/pdf/dec/pdp1/JPEGs/Type30...
- masswerk 12y ago
  A display similar to the Type 30 CRT can be seen in action in this video of a Bell-Labs educational film: http://www.youtube.com/watch?v=iwVu2BWLZqA http://www.youtube.com/watch?v=iwVu2BWLZqA ("The Incredible Machine", 1968). The video shows later equipment, a PDP-5 and a display that looks like a member of the 330/340-family, but the technology is the same. (Interactive graphics technology like in TX-2 and the PDPs was actually amazing, but apparently got lost over time-sharing ...)

watmough 12y ago

I'm old enough that my first experience of 'big computer' graphics in the mid-Eighties was on one of these: http://www.pdp8.net/tek4010/tek4010.shtml http://www.pdp8.net/tek4010/tek4010.shtml Tektronix 4010 storage tube display. It was actually pretty nice, as long as you just wanted to draw a picture.

sehugg 12y ago

I don't think they saved the photos verbatim -- rather, the idea was to use the CRT to slow-scan the photographs and analyze them by recording the light that transmitted through the film. http://www.computer-history.info/Page4.dir/pages/PDP.1.dir/ http://www.computer-history.info/Page4.dir/pages/PDP.1.dir/

ajross 12y ago

It's not a raster display. The beam is driven by two voltages for X and Y, so really what those numbers are actually saying is that it had a pair of 12 bit DACs (hardly shabby technology in 1961, but not a 4k monitor either).