Editing Atari PC4

{{Infobox computer
| name         = Atari PC4
| image        = 
| caption      = Atari PC4
| manufacturer = [[Atari Corporation]]
| type         = IBM PC/AT Compatible
| release date = November 1987 (announced at COMDEX); 1988 (shipping)
| discontinued = 1990
| price        = 
| cpu          = AMD 80286 @ 12 MHz or 16 MHz (switchable to 8 MHz)
| memory       = 1 MB RAM (expandable to 8 MB via 30-pin DIPP modules)
| storage      = 1× Epson SD-680L 5.25" 1.2 MB floppy drive; Seagate ST-277R 66 MB RLL hard drive; optional 1.44 MB 3.5" floppy
| display      = Onboard VGA graphics (Paradise PVGA1A-JK)
| sound        = PC Speaker
| os           = MS-DOS 3.30, GW-BASIC 3.2, Microsoft Windows/286 v2.1
| predecessor  = [[Atari PC3]]
| successor    = [[Atari PC5]]
}}
The '''Atari PC4''' was an IBM PC/AT-compatible computer manufactured by [[Atari Corporation]], announced alongside the [[Atari PC2|PC2]] at COMDEX '87 in November 1987. It was the first AT-class (80286-based) system in the Atari PC line and represented a significant step up from the XT-class PC1, PC2, and PC3 models.

The PC4 was also sold in some European markets — notably Sweden — as the '''Atari ABC 286''' (Atari Business Computer 286).

== Overview ==
The PC4 was the last model in the Atari PC series to feature an Atari-designed proprietary motherboard. It marked a departure from the earlier XT-class models in several ways: it used an AMD 80286 processor, included onboard VGA graphics (replacing the EGA of earlier models), and shipped with a larger 66 MB hard drive.

In a move away from Atari-specific components, the PC4 dropped the Atari ST-compatible mouse port found on the PC1, PC2, and PC3. Both the keyboard and mouse were generic Mitsumi models — the same components used in other IBM-compatible systems of the era, including the Commodore PC line.

The PC4 was available in different speed configurations, with AMD 286 processors running at 12 MHz or 16 MHz (switchable down to 8 MHz for compatibility with software that required slower clock speeds).

== Specifications ==
{| class="wikitable"
|-
! Component !! Details
|-
| Processor || AMD 80286, configurable at 16, 12, or 8 MHz
|-
| Co-processor socket || Intel 80287
|-
| RAM || 1 MB (expandable to 8 MB using 30-pin DIPP modules)
|-
| Graphics || Onboard Paradise PVGA1A-JK VGA controller, supporting VGA (640×480, 256 colours)
|-
| Storage || 1× Epson SD-680L 5.25" 1.2 MB floppy drive; optional 1.44 MB 3.5" floppy drive; Seagate ST-277R 66 MB RLL hard drive
|-
| Hard drive controller || Data Technology Corporation DTC7187 RLL controller
|-
| Expansion || 5× 16-bit ISA slots + 1× 8-bit ISA slot
|-
| Ports || Monitor port, RS-232 serial port, Centronics parallel port, keyboard port
|-
| Keyboard || Mitsumi KPQ-E99YC AT keyboard
|-
| Mouse || Mitsumi 2-button serial mouse
|-
| Sound || PC Speaker
|}

== Bundled Software ==
* Microsoft MS-DOS 3.30
* GW-BASIC 3.2
* Microsoft Windows/286 Version 2.1

The PC4 was the first Atari PC to ship with Microsoft Windows, reflecting the AT-class system's ability to run more demanding software.

== Atari ABC 286 ==
In certain European markets, particularly Scandinavia, the PC4 was marketed under the '''Atari ABC 286''' (Atari Business Computer) name. The ABC 286 came in several configurations:
* ''ABC 286/30'' — 8 MHz 80286, 640 KB RAM (expandable to 1 MB), 30 MB hard drive
* ''ABC 286/60'' — up to 20 MHz 80286, 1 MB RAM (expandable to 8 MB), 60 MB hard drive

The ABC 286 models featured slightly different chassis styling, 3× ISA expansion slots (reduced from the PC4's 6), and the option of a 3.5" 1.44 MB floppy drive — marking Atari's first PC-compatible use of the 3.5" format. Processor speeds across the ABC 286 range included 8, 10, 12, 16, and 20 MHz options, with an optional 80287 co-processor.

== See Also ==
* [[Atari PC3]]
* [[Atari PC5]]
* [[Atari ABC computers|Atari ABC Series]]

== External Links ==
* [https://www.ataripc.net/pc4-286/ AtariPC.net — Atari PC4 286-12/16]
* [https://binaryvalue.com/index.php/ibm-pc/atari-pcs BinaryValue — Atari PCs]

[[Category:Atari Systems]]
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