Atari 1040STFM
 | |
| An Atari 1040STFM | |
| Specifications | |
|---|---|
| Manufacturer | Atari Corporation |
| Type | Home computer |
| Released | Announced 26 May 1988 (London); on sale in the US from March 1989 |
| Discontinued | December 1992 |
| Intro price | US$799.95 (March 1989); US$699 (May 1990) |
| CPU | Motorola MC68000 at 8 MHz |
| Memory | 1 MB (32 × 256 kbit × 1 DRAM in two banks) |
| Storage | Internal 3.5-inch double-sided 720 KB drive; external drive on the 14-pin DIN; ACSI hard disks |
| Display | 320 × 200 (16 colours), 640 × 200 (4 colours), 640 × 400 monochrome; RF and composite output through the modulator |
| Sound | Yamaha YM2149 PSG, three channels |
| ROM | 192 KB TOS |
| Power | Internal switching supply, +5 V and +12 V only, 2 A fuse |
| OS / Firmware | Atari TOS 1.02 or 1.04 |
| Predecessor | Atari 1040STF |
| Successor | Atari 1040STE |
The Atari 1040STFM is a 1040STF with a television modulator: 1 MB of RAM, an internal double-sided drive, an internal power supply, and an RF output beside the 13-pin monitor socket. It was the last model of the original ST generation. Atari announced it in London on 26 May 1988; the German Atari museum dates its appearance to September 1988 and gives March 1989 as the start of US sales, at US$799.95.[1]
When the STE arrived in August 1989 the rest of the ST range was discontinued, but the 1040STFM stayed in production until December 1992, sold alongside the 1040STE as the cheaper machine.[1] A machine badged 1040STFM therefore dates from 1988 or later.
It uses the same boards as the 520STFM with both RAM banks fitted.[1] The features it shares with the 1040STF are described at Atari 1040ST, and the shared service data at Atari ST General Maintenance.
The modulator
[edit | edit source]The modulator turns the composite signal into an RF carrier for a television. A phase-locked loop locks the picture to the colour burst frequency; without it the colours shift and flicker on the television screen.[2] Atari's parts list gives the RGB encoder/modulator as MOD1 (C070517, NTSC) and the colour crystal as Y3, 3.579545 MHz.[2] Early boards had the phase-locked loop as a hand-wired modification; on some 1040STs it is on a small daughter board in front of the shield over the video Shifter.[2]
Atari's symptom checklist has one entry for this part of the machine: "T.V. output bad: modulator, phase locked loop. Trace signal with oscilloscope."[2]
The television and composite outputs carry only the low and medium resolutions (320 × 200 and 640 × 200). The 640 × 400 monochrome mode needs an Atari monochrome monitor such as the SM124 on the monitor socket, and the machine detects the monochrome monitor through an input on the MFP.[3] In the US the RF output is on channel 2 (55.25 MHz) or channel 3 (61.25 MHz).[3]
Power supply
[edit | edit source]The internal switching supply provides +5 V and +12 V only; there is no −12 V output.[2] It is rated at 3 A at +5 V and 0.9 A at +12 V. One adjustment sets both rails; Atari's instruction is to set the output within ±5 %, 4.75–5.25 V. It has a 2 A fuse, and Atari notes that because the supply has overcurrent protection a blown fuse usually means a catastrophic failure such as a shorted primary.[2]
Typical load is 2.2 A at +5 V and 160 mA at +12 V, rising to 2.3 A and 340 mA during disk access.[2]
The supply is mains-powered and holds a charge on the primary side after it is unplugged. Discharge the primary reservoir before working on it.
Board revisions
[edit | edit source]The German Atari museum lists two main-board part numbers for the 1040STFM:[1]
- C070789: also used in the 520STFM and the later 1040STF
- C103225: later STFM board
Servicing
[edit | edit source]- Atari ST General Maintenance
- Atari ST Troubleshooting Guide
- Atari ST Capacitor Replacement Guide
- Atari 520ST and 1040ST Computer Field Service Manual: Atari's field service manual, January 1987, including the 1 May 1986 1040STFM parts list
- Floppy Drive Repair
See also
[edit | edit source]References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 "Atari 1040ST", atari-computermuseum.de (in German). Secondary source for the 1040STFM announcement on 26 May 1988, its appearance in September 1988, US sale from March 1989 and US prices, the December 1992 end of production, the shared 520STFM board and the C070789 and C103225 board numbers.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Atari Corporation, 520ST / 1040ST Computer Field Service Manual, part number C026118-002 Rev B (3.6), January 1987: section 1 for the STFM designation and the internal supply rating, fuse and adjustment; section 2 (audio/video subsystem) for the phase-locked loop and its hand-wired and daughter-board forms; section 5 "Symptom Checklist" for the T.V. output entry; section 7 (1040STFM parts list, 1 May 1986) for MOD1 and Y3; section 9 glossary for the phase-locked loop. Hosted on this wiki as File:Atari 520ST and 1040ST Computer Field Service Manual.pdf.
- ↑ 3.0 3.1 Atari Corporation, Engineering Hardware Specification of the Atari ST Computer System, 7 January 1986, video interface section: supported resolutions by display type, the monochrome monitor detect interrupt on the MFP, and the channel 2 and 3 carrier frequencies. Hosted on this wiki as Atari ST Engineering Hardware Specification (PDF).