Atari Megafile 30
| Atari Megafile 30 | |
|---|---|
 |
|
| A Megafile 30 on top of a Mega ST2 and a Mega 2 | |
| Manufacturer | Atari Corporation |
| Type | External hard disk drive |
| Interface | Atari DMA hard disk port, 19-pin; Hard Disk In and Hard Disk Out sockets[1][2] |
| Compatible | Atari Mega ST and ST computers[1] |
| Dimensions | 34 × 34 × 7 cm (13.4 × 13.4 × 2.75 in)[2] |
| Weight | 4.27 kg (9.4 lb)[2] |
| Predecessor | Megafile 20 (SH205)[3] |
| Power | Internal mains supply, 120 V 60 Hz (US) or 240 V 50 Hz (UK); 14.8 W[2] |
| Storage | 32,747,520 bytes formatted, RLL[2] |
The Atari Megafile 30 is a 30-megabyte external hard disk drive that Atari Corporation sold for its Mega ST and ST computers. It connects to the computer's hard disk (DMA) port, and its flat case stacks with a Mega ST: Atari's manual puts the computer on the drive and the monitor on the computer.[1] The case holds a mains power supply, a fan, a controller board drawn by Atari and an ST412-interface RLL drive mechanism, which Schaltungsdienst Lange's service compilation names as a Seagate ST238R.[4][5] The Atari Megafile 60 has the same controller drawing and owner's manual with a larger mechanism.[2][4]
History
[edit | edit source]ST-Log reported in January 1989 that Atari's Megafile 20, which also went by the name SH205, had replaced the discontinued SH204 at a list price of US$680.[6] In December 1989 ANALOG Computing wrote that Atari had ended production of the Megafile 20 and made the Megafile 30 its entry model, with the Megafile 60 and Megafile 44 above it, and that the new 30 and 60 were RLL drives where the Megafile 20 had used MFM.[3] Atari's owner's manual for the 30 and 60 carries a 1988 copyright, and the controller schematic was drawn on 23 March 1988.[7][4] Best Electronics, a US Atari parts dealer, lists reconditioned units as "Megafile 30 / SH305".[8]
Specifications
[edit | edit source]| Item | Value |
|---|---|
| Formatted capacity | 32,747,520 bytes |
| Platters, surfaces, heads | 2, 4, 4 |
| Cylinders | 615 (2,460 tracks) |
| Track density | 588 tracks per inch |
| Data format | RLL, 7.5 Mbit/s |
| Rotational speed | 3,600 rpm ±1.0 % (latency 8.33 ms) |
| Average seek | 65 ms |
| Mains supply | 120 V 60 Hz (US) or 240 V 50 Hz (UK) |
| Power consumption | 14.8 W |
| Start and stop | 22 s typical from power-up to ready; 20 s to stop |
| Operating temperature | 10 to 50 °C |
| Shock | 40 g non-operating, 4 g operating |
Atari adds that Megafiles "may use parts from different manufacturers", so an individual drive can differ from these figures.[2]
Hardware
[edit | edit source]Drive mechanism
[edit | edit source]The Schaltungsdienst Lange compilation ends with Seagate's table of ST412-interface RLL drives and the typed note "Segate ST 238 R in der Megafile 30". Seagate's figures for the ST238R in that table (four heads, 615 cylinders, 65 ms access, 14.8 W) are the same as Atari's specification for the Megafile 30.[5][2] Owners on atari-forum also name the ST238R as the drive fitted.[9][10] Atari's specification warns that parts may come from different manufacturers, and its 1989 errata sheet adds a step to formatting in which HDX asks the user to pick, from a list, the label number printed on the rear of the drive.[2][11]
Controller board
[edit | edit source]Atari drawing C103166 Rev. 4, titled Schematic Diagram, Megafile 60 (RLL), is the controller schematic in the compilation, which presents it for both models.[4] The one board carries both the DMA host adapter and the disk controller. An 8085 processor (U7, 6 MHz crystal) runs it from a 64K ROM (U14) with a 2116 static RAM (U16). The disk side uses Adaptec's AIC-300 (U15) and AIC-010 (U17) and a 32D5321 data separator (U12) with its own 15 MHz crystal, and the 3486 receiver and 3487 driver (U1, U4) handle the data cables. Two 19-pin DMA connectors (J6, J7) take the bus in and out again for the next device. A three-position switch, SW1, sets the unit number through the 74LS85 comparator U18.[4] The revision block records Rev. 2 as "revised to improve daisy chain" and Rev. 4 as "revised per ECO no. 00812".[4]
Power from the supply enters on J5 (+5 V on pins 1 and 2, +12 V on pin 6) and leaves on J9 for the drive and J8 for the fan.[4]
Not every Megafile 30 has this board. In 2022 an owner found the controller in his Megafile 30 marked "SH205 C100169 REV.5", and another forum member noted that its U3 is a 40-pin chip where the C103166 drawing has a 74LS51.[12] Read the number on the board before working from the drawing.
Power supply and cooling
[edit | edit source]The internal supply is built for one mains voltage. Atari's specification lists 120 V 60 Hz for the United States and 240 V 50 Hz for the United Kingdom, and Best Electronics replaced the internal 110 V supply of a US unit with a 220/240 V one before sending it to a customer in the UK.[2][8] For a UK mains lead with a 13 A (BS 1363) plug, Atari specifies a 3 A fuse.[13] A fan, fed from J8, cools the drive through vents in the case, and Atari warns that papers pushed between the drive and a computer stacked on it block the vents.[1][4] No schematic or parts list for the supply is in the hosted documents.
Setting up
[edit | edit source]
The drive comes formatted and partitioned. Atari's default for the Megafile 30 is three partitions of 10 megabytes.[14] A system booting from floppy needs AHDI.PRG in the AUTO folder to see the drive; HINSTALL writes the driver (SHDRIVER.SYS) so the system can boot from the hard disk.[1][15]
Every Megafile leaves the factory set to unit 0. Up to four Megafiles or other DMA devices are recommended on one chain (eight are possible), each with its own unit number set on the internal DIP switches, which Atari told owners to have changed at a service centre. The cable runs from the computer's Hard Disk port to Hard Disk In on the first drive, and from Hard Disk Out to Hard Disk In on the next. An SH204 on the same chain has to be the last device.[1]
Switch the drive on before the computer. The busy light blinks and the drive spins up; when the light goes out and the whirring stops, switch on the computer. Switch the computer off first. Park the heads with SHIP.PRG or the HDX Ship option before moving the drive.[1][16]
Known faults
[edit | edit source]Owners report these faults in the drive mechanism: a drive that clicks and is not recognised, drives that collect bad sectors until a fresh low-level format clears them for a while, drives that stick or are slow to start, and one that stopped reading after about half an hour as it warmed up.[9][10][17] Replacement RLL mechanisms are scarce, and owners now fit MFM drive emulators or replace the controller with a SCSI host adapter.[17][10] Forum members also advise replacing the electrolytic capacitors in the power supply.[9][18] See the Atari Megafile Troubleshooting Guide and Atari Megafile General Maintenance.
Documentation
[edit | edit source]Atari's owner's manual, its errata and partitioning addendum, and the compilation containing the controller schematic are hosted and described on Atari Megafile Documentation.
Related pages
[edit | edit source]- Atari Megafile 60
- Atari Megafile General Maintenance
- Atari Megafile Troubleshooting Guide
- Atari Megafile Documentation
- Atari Mega ST
- Hard Drive Maintenance and Repair
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Atari Corporation, MEGAFILE Hard Disk Drive Owner's Manual, C300459-001 Rev. B, 1988, chapter 1, pp. 3-8 (PDF pp. 7-12): contents of the box, stacking under a Mega, air vents, connecting one or more drives, DIP switches and unit numbers, switching on and off, the utilities disk. Hosted as File:Atari Megafile Owner's Manual C300459-001 Rev B.pdf.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 Atari Corporation, MEGAFILE Hard Disk Drive Owner's Manual, C300459-001 Rev. B, 1988, appendix C, "MEGAFILE Specifications", pp. 53-54 (PDF pp. 53-54).
- ↑ 3.0 3.1 Gregg Anderson, "Massaging Your MegaFile", ANALOG Computing issue 79, December 1989, p. 114: end of Megafile 20 production, the Megafile 30, 60 and 44, RLL.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Atari Corporation, Schematic Diagram, Megafile 60 (RLL), drawing C103166 Rev. 4, drawn 23 March 1988, in Schaltungsdienst Lange, Megafile 30, Megafile 60 Service Manual, PDF pp. 2-3. Hosted as File:Atari Megafile 30 and 60 Service Manual (Schaltungsdienst Lange).pdf.
- ↑ 5.0 5.1 Schaltungsdienst Lange, Megafile 30, Megafile 60 Service Manual, PDF p. 6: Seagate data table for ST412-interface RLL drives, with the note "Segate ST 238 R in der Megafile 30".
- ↑ "ST News: Megafile 20", ST-Log issue 27, January 1989, p. 9.
- ↑ Atari Corporation, MEGAFILE Hard Disk Drive Owner's Manual, C300459-001 Rev. B, notice page (PDF p. 2): copyright 1988, Atari Corporation.
- ↑ 8.0 8.1 Best Electronics, "Hard-Drives" (retrieved 6 October 2026): reconditioned "Megafile 30 / SH305" and a customer's US supply exchanged for a 220/240 V one. Vendor page.
- ↑ 9.0 9.1 9.2 atari-forum.com, "megafile 30 problem - clicking noises!", October-November 2005: clicking Megafile 30, the Seagate ST238R, advice to recap the power supply. Forum thread.
- ↑ 10.0 10.1 10.2 atari-forum.com, "Atari MegaFile Hard Drive Replacement", October 2006 to January 2023: RLL replacement drives, ST-238R data loss cured for a time by low-level formatting, a Megafile 30 that fails when warm, SCSI conversions. Forum thread.
- ↑ Atari Corporation, errata sheet for the MEGAFILE owner's manual, C300707-001 Rev. A, 1989: unit type dialog box and the label on the rear of the drive. Hosted as File:Atari Megafile Owner's Manual Errata C300707-001 Rev A.pdf.
- ↑ AtariAge Forums, "Megafile capacitor replacement", August 2022: a Megafile 30 with an SH205 C100169 Rev. 5 controller board. Forum thread.
- ↑ Atari Corporation, MEGAFILE Hard Disk Drive Owner's Manual, C300459-001 Rev. B, 1988, appendix D, "Power Connection in the United Kingdom", pp. 55-56.
- ↑ Atari Corporation, MEGAFILE Hard Disk Drive Owner's Manual, C300459-001 Rev. B, 1988, p. 11 (PDF p. 14): default partition sizes table.
- ↑ Atari Corporation, MEGAFILE Hard Disk Drive Owner's Manual, C300459-001 Rev. B, 1988, chapter 3, pp. 25-28: installing the hard disk driver with HINSTALL and booting.
- ↑ Atari Corporation, MEGAFILE Hard Disk Drive Owner's Manual, C300459-001 Rev. B, 1988, pp. 31-34 (PDF pp. 33-36): parking and unparking the drive heads.
- ↑ 17.0 17.1 AtariAge Forums, "Two dead Megafile 30s, options for MF drives", April 2024: MFM emulators, SCSI host adapters, drives revived by low-level formatting or by running for an hour. Forum thread.
- ↑ AtariAge Forums, "Install Megafile 60", January 2017: a Megafile 60 that reports "no identification", with advice to recap the power supply. Forum thread.