Atari 520STE
 | |
| An Atari 1040STE. The 520STE uses the same case and board with one bank of RAM. | |
| Specifications | |
|---|---|
| Manufacturer | Atari Corporation |
| Type | Home computer |
| Released | October 1989 (France); September 1990 (Britain) |
| Discontinued | End of 1992 (production) |
| Intro price | £299 as the Discovery Extra Pack (July 1991); £249 (September 1992) |
| CPU | Motorola MC68000 at 8 MHz |
| Memory | 512 KB on two 256 KB 30-pin SIMMs (SIPPs on very early machines); up to 4 MB |
| Storage | Internal 3.5-inch double-sided floppy drive (720 KB); external floppy (14-pin DIN) and hard disk (DB-19) ports |
| Display | 320 × 200 (16 of 4096 colours), 640 × 200 (4 of 4096), 640 × 400 monochrome |
| Sound | Yamaha YM2149 programmable sound generator, plus 8-bit stereo DMA sound with LMC1992 volume and tone control |
| ROM | 256 KB TOS in two ROMs |
| Power | Internal switching supply, +5 V 3 A and +12 V 0.9 A, 2 A fuse |
| OS / Firmware | TOS 1.06, then TOS 1.62 |
| Predecessor | Atari 520STFM |
The Atari 520STE is the 512 KB model of the Atari STE (ST Enhanced). It has the same case, board, power supply and floppy drive as the Atari 1040STE, and Atari's service manual, which covers both, gives the second bank of RAM as the most significant difference between them.[1] Compared with the STF range, the STE adds a 4096-colour palette, 8-bit stereo DMA sound, the BLiTTER graphics chip, two extra game controller ports that also take paddles and a light gun or pen, and SIMM memory sockets.[1]
Atari showed the STE to the trade press at CeBIT in March 1989 and to the public in Düsseldorf in August 1989. The German Atari museum records the 520STE on sale in France from October 1989 and in Britain from 27 September 1990 as the 520STE Turbo Pack; the 1040STE reached the shops first in West Germany. The 520STE was built until the end of 1992, while the 1040STE continued until Atari left the computer market in 1994.[2] In Britain the 520STE Discovery Extra Pack cost £299 in July 1991 and £249 in September 1992.[2]
Hardware
[edit | edit source]The chip set is the 1040STE's: a 68000 CPU at U100, the BLiTTER at U101, the GSTMCU (U400), which combines the jobs of the ST's Glue and memory controller, the STE Shifter (U401), a DMA controller, WD1772 floppy controller, MC68901 MFP, two MC6850 ACIAs, the YM2149, two DAC0802 converters and an LMC1992 volume and tone controller for DMA sound. The 1040STE page gives Atari's full table of positions and part numbers.[1]
The display modes are the ST's: 320 × 200 with 16 colours and 640 × 200 with 4 colours, each from 4096, and 640 × 400 monochrome. The Shifter's palette registers hold four bits each for red, green and blue.[1] DMA sound plays 8-bit samples from memory in stereo or mono at about 50, 25, 12.5 or 6.25 kHz, through filters and the LMC1992 to the two phono sockets on the back panel.[1] Every STE board has the television modulator except the French Peritel version.[1]
Memory
[edit | edit source]Each 512 KB bank is a pair of 8-bit SIMMs forming the 16-bit memory bus, so the 520STE's 512 KB is one pair of 256 KB SIMMs. Atari's rules are that all SIMMs must be the same size, 256 kbit and 1 Mbit SIMMs cannot be mixed, all should have the same access time of 150 ns or faster, and 9-bit SIMMs may be used with the ninth bit ignored.[1] The German Atari museum notes that with two modules only sockets 0 and 2 are fitted and 1 and 3 stay empty, that very early machines used SIPP modules with pins in place of SIMMs, and that 512 KB, 1 MB, 2 MB, 2.5 MB and 4 MB configurations are possible.[2]
Ports
[edit | edit source]The back panel carries, from left to right, the RS-232 (modem), printer, hard disk (DMA) and external floppy connectors, the television output, monitor connector, power switch, stereo audio outputs (right and left), mains input and reset button. The left side has the cartridge slot, the two MIDI sockets and the two game controller ports; the floppy drive slot is on the right side.[1]
Power supply
[edit | edit source]The internal switching supply provides +5 V and +12 V, with a 2 A fuse, and Atari's instruction is to adjust it to 5.1 V. It is rated at 3 A on +5 V and 0.9 A on +12 V, with 33.5 W maximum input. Typical demand in the machine is 1.75 A at +5 V and 86 mA at +12 V, rising to 2.2 A and 90 mA during disk access. The supply has overcurrent protection, so Atari notes that a blown fuse usually means a catastrophic failure such as a shorted primary.[1]
There is no −12 V output. Two TL497 switching regulators on the main board make the other supplies: U204 produces the positive and negative voltages, normally ±12 V, for the RS-232 line drivers, and U205 produces −5 V for the audio section, heavily filtered to keep switching noise out of the sound.[1] Dead RS-232 or noisy audio with a good +5 V rail points at these two circuits.
Operating system
[edit | edit source]The first STEs shipped with TOS 1.06 (ROM date 19 June 1989), which was soon replaced by TOS 1.62 (11 January 1990) because of a serious bug. The German Atari museum reports that some of the last machines may have had TOS 2.06.[2] The two ROMs are at U102 and U103.[1]
Servicing
[edit | edit source]To open the machine, turn it over and remove the six screws in the square holes; the three screws in the round holes hold the floppy drive. Lift off the top case and unplug the keyboard harness at the right front corner. For troubleshooting, the power supply can be left in place and the upper shield lifted off in one piece.[1]
Documentation
[edit | edit source]- Atari 520STE/1040STE Field Service Manual: Atari's STe 520/1040 Computer Field Service Manual, C302481-001 Rev A, August 1991.[1]
Related pages
[edit | edit source]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 Atari Corporation, Atari STe 520/1040 Computer Field Service Manual, part number C302481-001 Rev A, August 1991, in the retyped edition "updated by jer/eightbitter, May 2017" that is hosted here. Section 1 (models, panels, power supply, negative supplies, pp. 1–3), section 2 (theory of operation, main memory and SIMM rules, video, DMA sound, game controller ports), section 4 (disassembly, p. 43) and section 7 (parts list). Hosted on this wiki: Atari 520STE/1040STE Field Service Manual (PDF).
- ↑ 2.0 2.1 2.2 2.3 "Atari STE-Serie (520STE, 1040STE, 2080STE, 4160STE, 1040STE+)", atari-computermuseum.de (in German). Secondary source for the show and sale dates by country, UK prices, the end of production, SIMM socket use and SIPP modules, and the TOS versions and ROM dates.