IBM 740
Also known as | IBM 740 CRT Recorder and IBM 780 CRT display |
---|---|
Manufacturer | IBM |
Type | point display with generated axis |
Release date | 1954 |
Introductory price | US$2,850 (equivalent to $32,335 in 2023) a month rental |
Discontinued | 1959 |
Media | 35 mm photographic film |
CPU | IBM 701, IBM 704, IBM 709 |
Display | 7 inch CRT with P11 phosphor (740); 21 inch CRT with P7 phosphor (780) |
Graphics | 1024 x 1024 two level pixels (256 x 256 resolvable) |
Successor | IBM 2250 |
The IBM 740 CRT Recorder was announced in 1954 and used with the
Each point to be displayed was stored in a single 36 bit word, with 10 bits each for the X and Y coordinates, and 3 control bits, one to set either high or low intensity and two to indicate that an X or Y axis is to be drawn starting from the given point. If both the X and Y axis bits were set, a 45 degree line was drawn.
The 740's CRT used a short persistence P11 phosphor. The film used was 35 mm and was stored in a magazine that could hold up to 100 feet. ASA 200 speed film was recommended. The film could be advanced under computer control.
The IBM 780 CRT Display was a monitor that could be attached to the 740 and mirror to an operator what was being drawn on 740's CRT. The 780 had a 21-inch CRT with a longer persistence (2 second, nominal) P7 phosphor.
See also
References
- IBM 709 Data Processing System, Form A22-6501-0, 1958, p. 106ff.
- IBM Archive article about the 740
External links