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Atari 65XE

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Revision as of 04:11, 23 September 2026 by Josh (talk | contribs) (Rewritten against the XE-series Field Service Manual: ROM corrected to 24 KB (16 KB OS + 8 KB BASIC Rev C), not 16 KB as 10+6; power is +5 V through a 7-pin DIN from a brick containing the transformer, bridge and LM78S05 (5 V +/-5%, 1.5 A), no on-board regulator; SIO carries no supply rail; board assemblies CO70025/CA20097/CA200519 named; launch price sourced to Creative Computing March 1985)
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Atari 65XE
Atari 65XE home computer
Specifications
ManufacturerAtari Corporation
TypeHome computer
Released1985 (shown at the Winter CES, January 1985)
Intro priceUS$100-120 at launch
CPUMOS Technology 6502C @ 1.79 MHz (NTSC) / 1.77 MHz (PAL)
Memory64 KB RAM; 24 KB ROM (16 KB operating system + 8 KB Atari BASIC Rev. C)
StorageCassette (410/1010) or 5.25" floppy disk drive (1050/XF551) over SIO; ROM cartridge
Display40 x 24 text, up to 320 x 192 pixels
SoundPOKEY: four audio channels
OS / FirmwareAtari XE Operating System; Atari BASIC Rev. C in ROM
PredecessorAtari 800XL
SuccessorAtari 130XE
Model no.65XE

The Atari 65XE is the 64 KB member of Atari Corporation's XE range, shown at the Winter Consumer Electronics Show in January 1985 as the cost-reduced replacement for the Atari 800XL. Atari's marketing manager described the redesign at the time as "engineering optimization" - the same machine made cheaper and more reliable through the use of fewer parts - and priced it at the pre-January 800XL price of US$100 to US$120.[1] Atari stated that the 65XE was 100% compatible with the 800XL it replaced.[2]

Atari's field service manual for the XE line covers the 65XE directly: Section 2 carries the schematics and silkscreens for the CO70025, CA20097 and CA200519 65XE assemblies alongside the 130XE ones.[3]

Architecture and processor

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The 65XE uses the 6502C at 1.79 MHz (NTSC) or 1.77 MHz (PAL) with the XE chipset: ANTIC (display processor, which also controls bus access and RAM refresh), GTIA (colour and luminance generation from ANTIC's bit stream, plus player/missile graphics), POKEY (audio, SIO control, controller scan and keyboard scan), the PIA (general purpose I/O), FREDDIE (memory controller, which also generates the clock signal to the CPU) and the memory management unit MMU1, Atari part C061618.[3]

The master oscillator is 14.31818 MHz on NTSC machines and 14.187576 MHz on PAL machines.[3]

Memory

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  • 64 KB RAM. On the CO70025 and CA20097 assemblies this is eight 64K x 1 (4164)
 DRAMs; on the later CA200519 assembly it is two 64K x 4 (4464) DRAMs.[3]
  • 24 KB ROM - a 16K x 8 operating system ROM plus 8 KB of Atari BASIC Rev. C. The
 self-test memory screen represents the ROM as two 8 KB bars.[3]

Two operating-system ROM part numbers are documented for the XE line, C061598 and C300717. The difference is visible in the self test: a board fitted with C300717 shows four extra bars for the four 16 KB extended memory banks.[3] On a 65XE those extra bars have no RAM behind them - the extended banks are a 130XE feature.

Display, video output and sound

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Video is produced by ANTIC and GTIA: text up to 40 x 24, bitmap modes up to 320 x 192 pixels, four players and four missiles with collision detection, and programmable display lists with hardware fine scrolling.

The 5-pin DIN monitor jack carries:[3]

XE monitor jack pin assignments
Pin Signal
1 Monochrome (luminance) video output
2 Ground
3 Audio output
4 Composite video output
5 Colour (chrominance) output

RF output is through a built-in modulator with a channel 2/3 switch; the modulated signal is 1-2 mV into 75 ohms.[3]

POKEY provides four audio channels, keyboard scanning, controller scanning and the SIO serial port.[3]

Input, output and expansion

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  • Cartridge slot - 30-pin edge connector[3]
  • SIO port - 13-pin. Pin 1 clock in, 2 clock out, 3 data into CPU, 4 ground, 5 data out,
 6 ground, 7 command, 8 motor control, 9 proceed, 10 ready (computer on),
 11 audio in (175 mV), 12 not used, 13 interrupt[3]
  • Two controller jacks - 9-pin D-type; pin 7 is +5 V, pin 8 ground[3]
  • Monitor jack - 5-pin DIN
  • RF output with channel 2/3 switch
  • Power jack - 7-pin DIN

The XE range dropped the XL's 50-pin Parallel Bus Interface. Its replacement, the Enhanced Cartridge Interface (ECI) - a 14-pin extension sitting behind the 30-pin cartridge connector - was announced as a 130XE-only feature.[2] The later CA200519 board assembly is shared between the 130XE and the 65XE/800XE, so individual machines vary; check the rear panel of the actual unit rather than assuming from the model name.[3]

Power

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The 65XE takes +5 V DC through a 7-pin DIN power jack. The power jack, the power switch and the filtering are on the motherboard; everything else is in the external brick, which contains the step-down transformer (115 V or 230 V AC in, 9 V AC out), a bridge rectifier, an LM78S05 regulator, a 4700 uF reservoir capacitor and a 100 uF output capacitor. Atari rates the output at 5 V +/-5%, 1.5 A maximum.[3]

There is no rectifier, bridge or regulator on any XE motherboard. Descriptions of the XE power input as a "5.5 mm / 2.1 mm centre-positive barrel jack" are wrong for every machine in this range.[3]

Keyboard and self test

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The XE keyboard is a full-stroke alphanumeric keyboard with a space bar and five function keys: HELP, START, SELECT, OPTION and RESET.[3]

  • Holding OPTION while switching on disconnects the internal BASIC, and with no active
 disk drive the self test runs.[3]
  • HELP (or RESET) ends a looping self test and returns to the menu.[3]

The self test covers memory, audio/visual, keyboard, ports, ROM and RAM, and Atari's production test cartridge adds a numbered diagnostic error-code table - both are set out on the Atari 65XE Troubleshooting Guide.

Board assemblies

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65XE board assemblies documented by Atari
Assembly RAM Notes
CO70025 8 x 4164 (64K x 1) Schematic figure 2-7, silkscreen figure 2-8[3]
CA20097 8 x 4164 (64K x 1) 65XEN; schematic figure 2-9, silkscreen figure 2-8[3]
CA200519 2 x 4464 (64K x 4) Shared 65XE/800XE assembly; schematic figure 2-11, silkscreen figure 2-12[3]
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Service documentation

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Atari 65XE documentation
Main board schematic Field service manual
File:ATARI65XE-SCHEMATIC.pdf File:Atari 130XE Field Service Manual.pdf

The manual is also available as a page: Atari 130XE Field Service Manual. Despite its title it is the service manual for the whole XE range, including this machine.

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References

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  1. Tim Onosko and John J. Anderson, "Atari strikes back", Creative Computing Vol. 11 No. 3 (March 1985), p. 59, reproduced at atarimagazines.com. Contemporary report of the Winter CES 1985 line-up, written from briefings by Atari marketing manager Brian Kerr; source for the 65XE, 65XEM and XEP prices and the AMY specification quoted here.
  2. 2.0 2.1 Jack Powell, "130XE: How Atari's New 8-Bit Does It", Antic Vol. 4 No. 3 (July 1985), reproduced at atarimagazines.com. Atari's first published specification for the 130XE: bank-switching modes, the Enhanced Cartridge Interface signal list, and the 1.2 A at 5 V DC supply requirement.
  3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 3.20 3.21 Atari, 130XE Personal Computer Field Service Manual. Section 1 (theory of operation, chip pin assignments, external power supply schematic and rating, connector pinouts), Section 2 (schematics and silkscreens for all seven XE board assemblies), Section 3 (self test and production-test diagnostic error codes). Despite its title it covers the 65XE, the 800XE and the XE Game System as well. Hosted on this wiki: File:Atari 130XE Field Service Manual.pdf.