Atari 800XE Troubleshooting Guide

The Atari 800XE is a 64 KB machine on the 130XE's main board, the same as the PAL Atari 65XE with the expansion port.^[1] The chip map and supply pins, clock and reset test points, self test, Atari's production test error codes, connector pinouts and symptom guide on the Atari 130XE Troubleshooting Guide all apply. The differences are below.

Differences from the 130XE

**800XE and 130XE**
Item	800XE	130XE
RAM	Two 4464 (64K × 4) at U9 and U10, 64 KB^[2]	128 KB: sixteen 4164 or four 4464^[2]
Extended memory	None	A second 64 KB reached through $4000–$7FFF, selected through PIA port B
Bank-select decoder	Positions U34 and U35 are part of the unused bank-switching circuit^[2]	U34, Atari C025953^[3]

Supply

The 800XE takes +5 V DC from an external pack through the 7-pin DIN socket J7, and has no rectifier or regulator on the board.^[2]^[3] Measure the pack before connecting it, and if a pack has failed, check for a short between pins 3 and 1 of J7 with the power switch on before fitting a new one.^[4]

SIO pin 10 carries +5 V/ready on the XL and XE machines, and pin 12 is not connected.^[1] On Atari's 130XE schematic pin 10 is fed from +5 V through the ferrite bead L10 and decoupled by C79.^[3]

RAM faults

Each 4464 holds four of the eight data bits. Atari's production test halts on a RAM failure and shows the failing address, the data read, the data expected and bits 1–8 in red for bad and green for good, so a failure in one half of the byte points at one of the two devices.^[3]^[2]

On the 4464, V_CC is pin 9 and ground is pin 18, in the middle of the two rows of pins.^[2] The supply pins of the other chips are in the table on the Atari 130XE Troubleshooting Guide.

Related pages

References

↑ ^1.0 ^1.1 Michael D. Current (ed.), Atari 8-Bit Computers: Frequently Asked Questions, comp.sys.atari.8bit FAQ, last modified 29 November 2009, sections 1.9 "What is the Atari 800XE?" and 1.16 (port pinouts). faqs.org. Community reference.
↑ ^2.0 ^2.1 ^2.2 ^2.3 ^2.4 ^2.5 130XE Personal Computer Field Service Manual, reproduction by JER/Eightbitter (PDF author "Jurek"), November 2016, with schematics redrawn in May 2014; not an Atari publication. Section 2, figure 2-11 ("Schematic Atari 65XE/800XE 2 X 4464 Assembly CA200519") and figure 2-12; Section 3 (self test). Hosted here as Atari 130XE Field Service Manual (PDF).
↑ ^3.0 ^3.1 ^3.2 ^3.3 Atari (U.S.) Corp., 130XE Parts List, 25 June 1985, and the production test instructions (error codes, Rev. 3.4, 22 May 1986), with Atari (Japan) schematic C070065 Rev. B. Hosted here as Atari 130XE Parts List and Production Test Instructions (PDF).
↑ Howard W. Sams & Co., Sams COMPUTERFACTS CC16, Atari Model 130XE, service checks, p. IV. Hosted here as Sams Computerfacts Atari 130XE (PDF).

[faq-1] 1.0 ^1.1 Michael D. Current (ed.), Atari 8-Bit Computers: Frequently Asked Questions, comp.sys.atari.8bit FAQ, last modified 29 November 2009, sections 1.9 "What is the Atari 800XE?" and 1.16 (port pinouts). faqs.org. Community reference.

[fsm-2] 2.0 ^2.1 ^2.2 ^2.3 ^2.4 ^2.5 130XE Personal Computer Field Service Manual, reproduction by JER/Eightbitter (PDF author "Jurek"), November 2016, with schematics redrawn in May 2014; not an Atari publication. Section 2, figure 2-11 ("Schematic Atari 65XE/800XE 2 X 4464 Assembly CA200519") and figure 2-12; Section 3 (self test). Hosted here as Atari 130XE Field Service Manual (PDF).

[parts-3] 3.0 ^3.1 ^3.2 ^3.3 Atari (U.S.) Corp., 130XE Parts List, 25 June 1985, and the production test instructions (error codes, Rev. 3.4, 22 May 1986), with Atari (Japan) schematic C070065 Rev. B. Hosted here as Atari 130XE Parts List and Production Test Instructions (PDF).

[sams-4] Howard W. Sams & Co., Sams COMPUTERFACTS CC16, Atari Model 130XE, service checks, p. IV. Hosted here as Sams Computerfacts Atari 130XE (PDF).

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