Atari SC1425
| Atari SC1425 | |
|---|---|
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|
| SCART and TTL inputs on the Philips schematic supplied with an SC1425 | |
| Manufacturer | Atari Corporation; built by Philips[1] |
| Type | 14-inch RGB colour monitor |
| Release date | Third quarter of 1988[1] |
| Discontinued | 1991[1] |
| Interface | SCART (Euro-AV) RGB input; 8-pin DIN TTL RGB input; 3.5 mm headphone socket[1] |
| Compatible | Atari ST range except the ST Book; Falcon030 with an adapter[1] |
| Dimensions | 350 × 323 × 381 mm (W × H × D)[1] |
| Weight | 11 kg[1] |
| Power | 220-240 V AC; 75 W[1][2] |
| Resolution | 640 × 200 (ST medium resolution)[1] |
The Atari SC1425 is a 14-inch colour monitor that Atari sold for the ST range from the third quarter of 1988 until 1991. atari-computermuseum.de records that Philips built it in South Korea, that it is technically the same as the Commodore 1084S-D1, and that it was sold only in French-speaking Europe and the British Isles.[1] It has one loudspeaker on the left of the screen and a headphone socket.[3] The schematic supplied with one SC1425 is Philips's drawing for the CM8852/00 and CM8832 monitor chassis.[2]
The monitor has a colour CRT and a switch-mode power supply whose primary side the schematic marks "not mains isolated". Read CRT Discharge Procedure before opening the case.[2]
Specifications
[edit | edit source]| Item | Value |
|---|---|
| Picture tube | 14 in, 90° deflection, 0.425 mm slot mask[1] |
| Display | Colour, or green and black with the front-panel switch[1] |
| Resolution | 640 × 200[1] |
| Horizontal frequency | 15.625 kHz[1] |
| Vertical frequency | 50 or 60 Hz[1] |
| Video input | Analogue RGB (SCART); TTL RGB (8-pin DIN)[1][2] |
| Mains | 220-240 V AC, fuse VL101 2 A time-lag[2] |
| Power consumption | 75 W[1] |
Atari's May 1986 summary specification lists an "SC1425" with a 14-inch tube, a 0.31 mm dot pitch, 640 × 480 resolution and 31.5 kHz horizontal scan, and asks for a connector specification for the "SC1425 EST" monitor.[4] That is a planning specification for a different, higher-resolution design; the SC1425 that went on sale in 1988 runs at 15.625 kHz.[1]
Controls and connections
[edit | edit source]The front panel carries horizontal position, brightness, contrast and volume controls and the colour/green switch; vertical height, vertical centring and horizontal width are on the back.[1] atari-computermuseum.de lists two cables to the ST's 13-pin monitor socket: one to the SCART socket and one to the 8-pin DIN TTL socket.[1] Owners on Atari-Forum report that the TTL input takes digital RGB, as from a PC CGA card, and that an ST has to use the SCART input.[5] The two sources disagree on whether an ST can use the TTL input.
Hardware
[edit | edit source]The Philips schematic shows a switch-mode power supply with a BUT11A switching transistor (TS132) and a CNX62 optocoupler (IC101), giving +125 V, +26 V, +16 V, +12 V and +5 V lines. A TDA3505 (IC502) processes the RGB signals, a TDA2595 (IC402) handles sync and the horizontal oscillator, a TDA2653A (IC302) drives the vertical deflection, a BU508A (TS467) is the line output transistor and a TDA2611A (IC301) is the audio amplifier. The RGB outputs to the CRT use three BF869 transistors (TS711 to TS713). The TTL input goes through a separate interface board, assembly 1108, built round a 74LS368 and a 74LS05.[2]
The schematic covers two Philips models. Notes marked 2) apply only to the CM8832; a box on the drawing lists the CM8832 changes, including the deletion of C496, C497, R496, R301, R302, R307 and the audio cinch socket, and the addition of R304 (15 kΩ) and a headphone jack.[2] No Atari service manual for the SC1425 has been found.
Related monitors
[edit | edit source]atari-computermuseum.de gives the Commodore 1084S-D1 as technically identical to the SC1425.[1] The later Atari SC1435 is a different Philips design with stereo sound.[6]
Documentation
[edit | edit source]- Atari SC1425 Documentation: the Philips CM8852/CM8832 schematic supplied with an SC1425, and Atari's 1986 monitor specification memo.
Related pages
[edit | edit source]- Atari SC1425 Capacitor Replacement Guide
- Atari SC1425 Documentation
- Atari SC1224, Atari SC1435, Atari PTC1426
- CRT Discharge Procedure
References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 "Atari SC1425 RGB Color Monitor", in "Atari ST-Peripheriegeräte", atari-computermuseum.de, https://www.atari-computermuseum.de/st_peri.htm#sc1425. Secondary source for the maker, the 1084S-D1 equivalence, the sales area and dates, the specifications, the controls, the cables, the dimensions and the weight.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Philips, circuit diagram CM8852/00 and CM8832, 4822 727 31481 (PRS.01474), with the TTL interface "Schema B" (PRS.01496), scanned from the copy supplied with an Atari SC1425. File:Atari SC1425 Schematic (Philips CM8852 and CM8832).pdf.
- ↑ "Atari ST", Wikipedia, section "Peripherals". https://en.wikipedia.org/wiki/Atari_ST
- ↑ Atari Corp., Atari Monitor Summary Specifications, memo of 14 May 1986, pp. 1-2. File:Atari Monitor Summary Specifications (1986-05-14).pdf.
- ↑ "Atari SC1425 monitor TTL RGB port", Atari-Forum, posts by Philsan and 1st1, 1 May 2022. https://www.atari-forum.com/viewtopic.php?t=41832. Community report.
- ↑ "Atari SC1435 RGB Color Monitor", atari-computermuseum.de, https://www.atari-computermuseum.de/st_peri.htm#sc1435. Secondary source.