Editing PDP-1 (section)

===Graphics display===
The Type 30 Precision [[CRT display]] is a point plotting display device capable of addressing 1024 by 1024 addressable locations at a rate of 20,000 points per second.<ref name="DECmanual">{{Cite book |url=http://www.bitsavers.org/pdf/dec/pdp1/F15D_PDP1_Handbook_Oct63.pdf |title=PDP-1 Handbook |publisher=[[Digital Equipment Corporation]] |year=1963 |pages=33–36 |access-date=2022-03-22 |archive-url=https://web.archive.org/web/20210828035149/http://www.bitsavers.org/pdf/dec/pdp1/F15D_PDP1_Handbook_Oct63.pdf |archive-date=2021-08-28 |url-status=live |via=[[Computer History Museum#Software|Bitsavers]] |language=en}}</ref> A special "Display One Point On CRT" instruction is used to build up images, which have to be refreshed many times per second.<ref name="DECmanual" /> The CRT, which was originally developed for use in radar, is {{convert|16|in|cm}} in diameter and uses a long-persistence [[Phosphor#Standard phosphor types|P7 phosphor]].<ref name="BickleyVid">{{Cite AV media |url=https://www.youtube.com/watch?v=1EWQYAfuMYw |title=Lyle Bickley explains the PDP-1 (and we play the original Spacewar!) |date=2017-05-02 |last=CuriousMarc |access-date=2018-04-07 |archive-url=https://ghostarchive.org/varchive/youtube/20211211/1EWQYAfuMYw |archive-date=2021-12-11 |url-status=live |via=[[YouTube]]}}{{cbignore}}</ref> A [[light pen]] can be used with the Type 30 to pick points on the display. An optional character generator and hardware for line and curve generation are available.<ref name="DECmanual" />