Amstrad ALT-386SX
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Specs
| CPU | 386SX* 16MHz (Switchable to 8Mhz) |
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| RAM | 1MB, expandable to 2MB or 4MB |
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| FDD (A) | 3.5" HD 1.4MB |
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| HDD (#1) | 40MB[?] (Type 17) |
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| Video | VGA-compatible with socket for external monitor |
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| Screen | Backlit, 640x480, 32 grays, STN |
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| Keyboard | 85-key internal, AT-compatible socket |
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| Ports | 1x DB-25 Parallel, 2x DE-9 Serial |
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| Expansion | 1 half-length 16-bit ISA slot |
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| Battery | 2400mAh 12V Battery Pack, "2 hours usage" |
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| Supplied Software | MS-DOS 3.30,
video soft-switch utility, memory utility |
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*Unlike on the 486, SX here means a 286-style 16-bit bus, 386s never
had onboard FPUs. Since other models had 286s, Amstrad probably chose
the SX to reuse the same motherboard design.
Screws
All screws are M3 Phillips, units in millimeters
Exterior
| Location | Qty. | Pitch | Len. |
|---|
| Under handle | 4 | 1.5 | 8 |
| Under and near battery | 2 | 1.5 | 12 |
| Corner bottom | 1 | 1.5 | 35 |
| Middle bottom | 1 | 0.5 | 6 |
| Power socket (pan-head) | 2 | 0.5 | 8 |
| Card bay (pan-head) | 2 | 0.5 | 10 |
| Sides | 2 | 0.5 | 4 |
| Memory/ Coprocessor hatch | 3 | 0.5 | 6 |
Interior
| Location | Qty. | Pitch | Len. |
|---|
| FD caddy rear (w/ ground wire) | 1 | 1.5 | 8 |
| FD caddy sides (w/ washers) | 4 | 0.5 | 8 |
| vga to power tab, vga side | 1 | 1.5 | 8 |
| vga to power tab, power side (w/ washers) | 1 | 0.5 | 8 |
| HD caddy | 4 | 1.5 | 5 |
| Memory/ Coprocessor board | 5 | 1.5 | 8 |
Batteries
Clock: 3 nicad cells, 3.6v 400mAh. Likely to leak, replace immediately!
Soldered to motherboard in bottom of case. May be trickle-charged while
unit is powered?
Power: 10 nicad cells, 12v, 2400mAh. Charging regulated by inline thermostats.
Floppy Disk
Internal
Normally, all the odd pins of a floppy cable are ground or not
connected, but here some of them supply power.
| 1 | NC | 2 | HD/NORM |
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| 3 | NC | 4 | NC |
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| 5 | +5V | 6 | NC |
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| 7 | +5V | 8 | IDX |
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| 9 | +5V | 10 | DR0 |
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| 11 | +5V | 12 | DR1 |
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| 13 | GND | 14 | MR1 |
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| 15 | GND | 16 | MR0 |
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| 17 | GND | 18 | FDIRC |
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| 19 | GND | 20 | FSTEP |
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| 21 | GND | 22 | FWD |
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| 23 | GND | 24 | FWE |
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| 25 | GND | 26 | FTK0 |
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| 27 | GND | 28 | FWP |
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| 29 | NC | 30 | FRDD |
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| 31 | NC | 32 | FWS |
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| 33 | NC | 34 | DCHG |
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Pin #1 is bottom-left when looking at back of drive.
The key on the drive end of the cable is on the top,
but a standard drive/cable would have it on the bottom.
The location of the pins on the drive are the same, however.
External
| 1 | GND | 19 | HD/NORM |
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| 2 | GND | 20 | NC |
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| 3 | GND | 21 | NC |
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| 4 | GND | 22 | IDX |
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| 5 | GND | 23 | DR0 |
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| 6 | GND | 24 | DR1 |
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| 7 | GND | 25 | NC |
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| 8 | GND | 26 | MR1 |
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| 9 | GND | 27 | FDIRC |
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| 10 | GND | 28 | FSTEP |
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| 11 | GND | 29 | FWD |
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| 12 | GND | 30 | FWE |
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| 13 | GND | 31 | FTK0 |
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| 14 | GND | 32 | FWP |
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| 15 | GND | 33 | FRDD |
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| 16 | GND | 34 | FWS |
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| 17 | GND | 35 | DCHG |
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| 18 | NC | 36 | GND |
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Hard Disk
The harddrive appears to be standard IDE/PATA drive, except that
the Molex connector is unused—the power is supplied by a more compact 3 pin connector.
The BIOS definitely does not support LBA, and normally uses
preset drive parameters—Type 17 appears to work on
mine—but some of the sets are configurable for other CHS
values.
Power Supply
Motherboard
| 1 | +5V |
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| 2 | +5V |
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| 3 | +12V |
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| 4 | -12V |
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| 5 | -24V |
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| 6 | GND |
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| 7 | GND |
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Indicators
| 1 | Quick |
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| 2 | Trickle |
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| 3 | Power |
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| 4 | Off Alarm |
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| 5 | GND |
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Battery Pack
| 1 | Charge |
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| 2 | Discharge |
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| 3 | NC |
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| 4 | GND |
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Keyboard Shortcuts
Most of these are provided by the VGA soft-switch utility.
| Key | Mnemonic | Description |
|---|
| Ctrl+Alt+S |
Enter Setup (built-in) |
Enter BIOS setup from DOS |
| Ctrl+Shift+A |
Automap colors |
Toggle automatic mapping of textmode colors to grays |
| Ctrl+Shift+B |
Bold letters |
Toggle displaying bright-colored letters in a bold font |
| Ctrl+Shift+C |
Centering |
Change position of non-expanded picture on screen |
| Ctrl+Shift+D |
Display switch |
Switch between LCD and external monitor |
| Ctrl+Shift+E |
Expand mode |
Toggle stretching of 200/400 line modes to full screen |
| Ctrl+Shift+F |
Frame color |
Change color of frame around non-expanded picture |
| Ctrl+Shift+R |
Reverse video |
Invert image, swapping black with white, etc. |
| Ctrl+Shift+S |
Screen power |
Turn LCD on or off |
| Ctrl+Shift+W |
Width fixup |
??? |