Amstrad PC4386SX
.jpg) | |
| PC4386SX with its 10-inch colour monitor, from Amstrad's 1991 brochure | |
| Specifications | |
|---|---|
| Manufacturer | Amstrad plc |
| Type | Compact desktop personal computer (IBM PC/AT compatible) |
| Released | 1991 |
| Intro price | £1,699 + VAT with colour monitor, £1,499 + VAT with mono monitor (UK, September 1991) |
| CPU | Intel 80386SX at 20 MHz; 80387SX-20 socket |
| Memory | 4 MB, parity checked, expandable to 16 MB; 64 KB cache |
| Storage | 3.5-inch 1.44 MB floppy drive; 80 MB hard disk, 19 ms |
| Display | — |
| Sound | — |
| Graphics | Built-in VGA, compatible with EGA, CGA, MDA and Hercules |
| Ports / interface | Bi-directional parallel, RS232C serial, Amstrad keyboard and mouse, VGA, monitor power outlet |
| Expansion | Two half-length 16-bit ISA slots |
| Dimensions | 250 × 70 × 264 mm (W × H × D) |
| OS / Firmware | MS-DOS 3.3, Windows 3.0 and Amstrad Manager |
The Amstrad PC4386SX is a small-footprint 386SX desktop PC that Amstrad announced in 1991, with a 20 MHz 80386SX, 4 MB of memory, a 64 KB cache, an 80 MB hard disk and a 10-inch VGA monitor, in a steel case 250 mm wide and 70 mm high.[1][2] Amstrad's advertising claimed a footprint less than half that of most desktops and priced it at £1,699 plus VAT with the colour monitor, which uses a Sony Trinitron tube.[3]
History
[edit | edit source]Amstrad's brochure is dated March 1991. Amstrad PC International described it in mid-1991 as about to go on sale, alongside the ANB-386SX notebook and ACL-386SX colour laptop, at DM 4,995 or DM 5,595 depending on the monitor.[1][2] A UK advertisement in November 1991 gave prices correct at 1 September 1991 and carried a "Novell Labs tested and approved" mark.[3] Cliff Lawson of Amstrad lists it as the last of the "older AT" Amstrad PCs, before the 5000 series.[4]
Specifications
[edit | edit source]| Item | Value |
|---|---|
| Processor | 80386SX at 20 MHz; socket for an 80387SX-20 |
| Memory | 4 MB, parity checked, expandable to 16 MB on the board; configurable as base (256, 512 or 640 KB), extended and LIM-EMS |
| Cache | 64 KB |
| Real-time clock | Integral battery, quoted at 10 years' life |
| Floppy drive | 3.5-inch 1.44 MB |
| Hard disk | 80 MB, 19 ms, with look-ahead cache |
| Expansion | Two half-length 16-bit ISA slots |
| Video | On-board VGA (EGA, CGA, MDA and Hercules compatible) |
| Keyboard and mouse | 102-key AT-style slim keyboard; Amstrad mouse |
| Ports | Bi-directional parallel, RS232C serial, Amstrad keyboard and mouse, VGA monitor, monitor power |
| Monitors | 10-inch high-resolution flat-screen VGA mono; 10-inch VGA colour, 0.26 mm dot pitch |
| Size | 250 × 264 × 70 mm (W × D × H) |
| Software | MS-DOS 3.3, Windows 3, Amstrad Manager |
Source: the brochure's specification page.[1]
Hardware
[edit | edit source].jpg)
Amstrad's photograph of the motherboard (marked MC0124A) shows a Dallas DS1287 real-time clock module, the 80386SX, an empty co-processor socket and four BIOS EPROMs labelled AMS41110 to AMS41113, with the expansion riser across the board.[1] The brochure lists easy access to the memory, the slots and the co-processor socket, a steel case, and mains power for the monitor switched through the system unit.[1]
Memory is on four identical 30-pin parity SIMMs, set by links LK27 to LK30 for size and LK25 and LK26 for speed; other links disable each built-in device and select the mouse interrupt and speaker volume.[4] The keyboard and mouse use Amstrad's own interfaces, which Amstrad replaced with PS/2-compatible ones from the 5000 series.[5][1] The floppy drive is of the same 26-way type as the PC5086's. The power supply feeds the motherboard through a main connector and a small four-way connector, SK106; one owner who replaced the supply found that the board would only start if the +5 V line on SK106 came up a second or two after the others.[6]
Software and configuration
[edit | edit source]SETUP is built in: Lawson gives Ctrl-Alt-S at the DOS prompt for the 4000 series, and the start-up screen offers Ctrl-Alt-S to run it.[4][7] The machine was supplied with MS-DOS 3.3, Windows 3.0 and Amstrad's own Windows front end, Amstrad Manager. One owner's machine also came with the games pack that Amstrad bundled with the PC5286 and with the same AdLib-compatible sound card.[2][8][9] During the extended memory test the BIOS shows alternating / and \ characters after the third self-test dot.[10]
Known faults
[edit | edit source]- The clock module's battery runs out, giving "WARNING: CMOS battery failed" at start-up; the machine in the Centre for Computing History shows this message.[7] One owner replaced the module with a DS12887, and another repaired the original DS1287.[11][6]
- Power supplies fail: one owner bought a PC4386SX with a burned-out supply and got it running on a picoPSU, planning an LM2662 converter for the negative rails.[6]
- The floppy drive fails, and new belts have not cured it; a Gotek on an adapter works.[6]
See the Amstrad PC4386SX Maintenance Guide and the Amstrad PC4386SX Troubleshooting Guide. No capacitor list has been published: the acpc.me archive lists the PC4386SX service manual, which also covered the PC-10HRCDR and PC-10MDR monitors, as missing, and no scan is known.[12]
Documentation
[edit | edit source]- PC4386SX brochure (1991) – Amstrad's five-page brochure with the specification table and a motherboard photograph
- No user manual or service manual for the PC4386SX is available online.[12]
- Amstrad PC3000, PC4386SX and PC5000 Sales Leaflets – all six Amstrad leaflets and brochures
Related pages
[edit | edit source]- Amstrad PC3386SX · Amstrad PC5286 · Amstrad PC5086
- Floppy Drive Repair · Hard Drive Maintenance and Repair
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Amstrad plc, PC4386SX brochure, © March 1991, pp. 4–5 (feature highlights, motherboard photograph, specification table). Hosted as File:Amstrad PC4386SX brochure (1991).pdf.
- ↑ 2.0 2.1 2.2 Thomas Kallay, "Big power in little case: PC4386SX", Amstrad PC International, June/July 1991, pp. 51–52. Internet Archive. Retrieved 2026-10-02. Preview of the PC4386SX before delivery: size, memory, disk, cache, monitors, slots, software and German prices.
- ↑ 3.0 3.1 Amstrad plc advertisement, "Amstrad's new baby is even smaller than most miniature PC's", Amstrad User, November 1991, p. 57. Internet Archive. Retrieved 2026-10-02. PC4386SX specification and prices, correct at 1 September 1991.
- ↑ 4.0 4.1 4.2 Cliff Lawson (Amstrad plc), "Older AT PCs" (atpcs.htm), from his Amstrad support pages at web.ukonline.co.uk/cliff.lawson, as preserved at freetimeweb.nl. Retrieved 2026-10-02. SETUP on the 3xxx and 4xxx series, the BIOS 2.xx of the 3xxx series, memory links for the 3286, 3386SX and 4386SX, video DIP switches and option links.
- ↑ Cliff Lawson (Amstrad plc), "General notes on Amstrad PCs" (general.htm), as preserved at freetimeweb.nl. Retrieved 2026-10-02. Amstrad's proprietary keyboard and mouse interfaces up to the 4386, PS/2-compatible ones from the 5xxx series, and a summary specification of each PC.
- ↑ 6.0 6.1 6.2 6.3 Vogons forum, "AMSTRAD PC 5086 - Floppy Drive Problems", Perro, tecnico, Jason_rg, flufetor, aotta69 and gca, May 2020 to August 2021. Retrieved 2026-10-02. Belt replacement on the original drives, a 26-pin to 34-pin adapter, capacitor failures in PC5286 power supplies and boards, and the PC4386SX power connector pinout.
- ↑ 7.0 7.1 Centre for Computing History, "Amstrad PC4386SX Computer" (CH63138), 1991. Retrieved 2026-10-02. Photographs of a complete system showing "WARNING: CMOS battery failed".
- ↑ Vogons forum, "Amstrad PC5268 bundled games", Banjo and gca, September 2018. Retrieved 2026-10-02. The PC5286 games pack and its "Series 5" system disk; gca's PC4386SX with the same bundle, MS-DOS 3.3 and Windows 3.0.
- ↑ Vogons forum, "Amstrad Adlib Clone: Restoration and Testing", brassicGamer and others, April 2016 to May 2017. Retrieved 2026-10-02. The Amstrad OPL2 sound card 3100-015P-4 bundled with the PC5286; gca reports the same card in his PC4386SX.
- ↑ "AMS-Line: Der Informationsdienst der Firma AMSTRAD", Amstrad PC International (page header CPC), August/September 1991, p. 7. Internet Archive. Retrieved 2026-10-02. Amstrad GmbH's column: the meaning of the start-up dots, the PC4386SX BIOS indicator, and the interrupt and I/O address tables of the PC3086, PC3286 and PC3386SX.
- ↑ Vogons forum, JidaiGeki's replies in "Amstrad 5086 - worth a go?" (March 2016) and "Amstrad 3286" (September 2024). Retrieved 2026-10-02. The PC4386SX's socketed Dallas clock module, replaced with a DS12887.
- ↑ 12.0 12.1 acpc.me (ACME) archive, Amstrad PC section, directory DOCUMENTS_TECHNIQUES/SERVICE_MANUALS. Retrieved 2026-10-02. The PC3086/PC3286/PC3386SX, PC4386SX and PC5086/PC5286 service manuals are listed with placeholder images only, marked missing.