Atari 600XL
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| Atari 600XL | |
| Specifications | |
|---|---|
| Manufacturer | Atari, Inc. |
| Type | Home computer |
| Released | Announced June 1983; produced autumn 1983 to summer 1984 |
| Discontinued | By July 1984 |
| CPU | 6502C (SALLY) at 1.79 MHz (NTSC), 1.77 MHz (PAL) |
| Memory | 16 KB RAM in two 16K × 4 DRAMs, expandable to 64 KB through the Parallel Bus Interface; 24 KB ROM |
| Storage | Cassette or floppy disk drive over SIO; ROM cartridge |
| Display | ANTIC and GTIA; RF output on all models, monitor socket on PAL models only |
| Sound | POKEY, four channels |
| Power | External supply CA061982, +5 V DC ±2 %, 1.5 A, 7-pin DIN |
| OS / Firmware | Atari XL operating system; Atari BASIC Rev. B built in |
| Predecessor | Atari 400 |
| Model no. | 600XL |
The Atari 600XL is the entry-level model of Atari's XL range, announced with the Atari 800XL in June 1983 as the replacement for the Atari 400.[1][2] It uses the same custom chips as the 800XL and runs the same software, but has only 16 KB of RAM, and the North American model has no monitor output.[3][2] Atari, Inc. built it in Hong Kong and Japan from autumn 1983 to summer 1984, and production had stopped by July 1984.[2] Some late machines, apparently only in Canada, were sold with 64 KB fitted and a gold sticker on the box.[2]
Atari's 600XL Computer Field Service Manual (FD100610 Rev. 1, October 1983) is the source for the hardware detail below.[4]
Architecture and processor
[edit | edit source]The CPU is the 6502C, Atari part C014806, with a single +5 V supply and an integral clock circuit.[4] This is Atari's SALLY version of the 6502, which adds a HALT input on pin 35; it runs at 1.7897725 MHz on NTSC machines and 1.7734470 MHz on PAL machines.[2] The support chips and their positions are:[4]
| Position | Device | Atari part number |
|---|---|---|
| U1 | 74LS138 decoder | C061428 |
| U2 | MMU 1B memory management unit (PAL) | C061618 |
| U3 | OS ROM, 16K × 8 (27128) | C061598 |
| U4 | Atari BASIC Rev. B ROM, 8K × 8 (2764) | C060302 |
| U5, U6 | 74LS158 multiplexer | C014345 |
| U7 | 74LS08 quad AND | C017097 |
| U8 | LM358 dual op-amp | C061702 |
| U9 | ANTIC Rev. E | C021697 (domestic); C021698 (international) |
| U10 | 6502C CPU | C014806 |
| U11, U12 | 16K × 4 DRAM | C061505 |
| U13 | Delay module | C060472 |
| U14 | 74LS14 hex inverter | C061850 |
| U15 | 74LS375 latch | C060613 |
| U16 | 74LS51 AND-OR-invert | C060474 |
| U17 | GTIA | C014805 |
| U18 | 74S32 quad OR | C061622 |
| U19 | CD4050B hex buffer | C010816 |
| U20 | POKEY | C012294 |
| U21 | PIA | C014795 |
| U22, U23 | CD4051B keyboard multiplexers | C014336 |
All of these positions are socketed. The crystal Y1 is 3.579545 MHz (C061090) on domestic machines; the schematic is drawn for the domestic and UK versions together, with a 3.546894 MHz crystal (C015510) for the UK.[4] Atari's Tech Tip 20 (17 August 1983) reports that "the first 24 K International and possibly some of the Domestic" 600XLs left the factory with the wrong ANTIC and fail the Super SALT RAM test and software that turns the screen off; the international part is C021698 and the domestic part C021697, both at U9.[4]
Memory
[edit | edit source]RAM is two 16K × 4 DRAMs at U11 and U12, giving 16 KB. Atari's expansion is the 1064 48K Memory Expansion Module, which plugs into the Parallel Bus Interface and takes the machine to 64 KB.[4] ROM is 24 KB: a 16K × 8 operating system ROM at U3 and an 8K × 8 Atari BASIC Rev. B ROM at U4. Built-in BASIC behaves like a permanently fitted cartridge, and a cartridge in the slot takes precedence over it in hardware.[4]
Input, output and expansion
[edit | edit source]| Position | Connector | Notes |
|---|---|---|
| J1 | SIO, 13 pins (C012995) | Pin 10 is +5 V/ready, pin 12 not connected; 19.2 kbaud maximum |
| J3 | Cartridge, 30 pins (C014389) | |
| J4 | Power, 7-pin DIN (C061838) | Pins 1, 4 and 6 +5 V; 3, 5 and 7 ground return; 2 ground |
| J5, J6 | Controller jacks, 9-pin D (C010448) | Pin 7 +5 V, pin 8 ground |
| J8 | Keyboard header, 24 pins (C061793) | 24-conductor ribbon cable |
| – | Parallel Bus Interface, 50-pin edge connector | Unbuffered address, data and control signals |
The RF modulator (UM1652E, C061619) produces 1 to 2 mV into 75 Ω with a 4.5 MHz sound carrier; channel 2 has its video carrier at 55.25 MHz and channel 3 at 61.25 MHz, chosen by the channel switch SW2.[4]
The North American 600XL has no monitor socket and drives only a television.[3] The PAL model has a monitor socket, without separate luminance and chrominance signals, and no channel switch; Atari's schematic shows the UK additions in dotted boxes, including a monitor output J7.[2][4]
Keyboard
[edit | edit source]The keyboard is 3/4-stroke with 56 keys: 55 alphanumeric keys including special characters and controls, and the space bar, plus four function keys and a RESET key. It connects to the board by a 24-conductor ribbon cable, and the key matrix is read through the two CD4051B multiplexers at U22 and U23.[4] Holding OPTION at power-on disables the built-in BASIC, and with no cartridge or diskette the self-test menu appears. HELP returns to that menu from an individual test; Atari notes that it does not work as it does on the 1200XL.[4]
Power
[edit | edit source]The 600XL takes +5 V DC through the 7-pin DIN at J4. The external supply, Atari part CA061982, accepts 110 V AC and provides +5 V DC ±2 %, 1.5 A maximum.[4] Atari's parts list for the board has no rectifier or voltage regulator: the 5 V from the brick passes through the power switch SW1 to three filtered rails, +5A, +5B and +5C.[4] Antic described the XL machines as the first Atari computers to run from a single 5 V DC supply.[3]
The connector is a 7-pin DIN, not a barrel jack. Measure a supply at its plug before connecting it: the board has no regulator between the brick and the custom chips.[4]
Comparison with the Atari 800XL
[edit | edit source]| Feature | Atari 600XL | Atari 800XL |
|---|---|---|
| RAM | 16 KB (two 16K × 4)[4] | 64 KB (eight 64K × 1)[5] |
| ROM | 16 KB OS + 8 KB BASIC Rev. B[4] | 16 KB OS + 8 KB BASIC Rev. B[5] |
| Keyboard multiplexers | U22, U23[4] | U24, U25[5] |
| Monitor socket | PAL model only[2] | 5-pin DIN, J2[5] |
| Power supply | +5 V ±2 %, 1.5 A maximum[4] | +5 V ±2 %, 1.2 A maximum[5] |
| OS identifier, PEEK(65527) | 1[3] | 2[3] |
Checking a machine
[edit | edit source]- The operating system can be identified from BASIC with
PRINT PEEK(65527); a 600XL returns 1.[3] - Hold OPTION while switching on, with no cartridge and no powered disk drive, to reach the self test; HELP returns to its menu.[4]
- Atari's deeper diagnostic is the Super SALT cartridge with its extended hardware test module, which tests voltages, SIO and the controller ports.[4]
Related pages
[edit | edit source]- Atari 600XL General Maintenance
- Atari 600XL Troubleshooting Guide
- Atari 600XL Capacitor Replacement Guide
- Atari 600XL Field Service Manual
- Atari 800XL
- Atari 400
References
[edit | edit source]- ↑ "The Atari 1400XL Computer Systems", Atari Museum (Curt Vendel): "In June of 1983 Atari would follow up from the announcements of the 600XL and 800XL with its other computers". Secondary source.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Michael D. Current (ed.), comp.sys.atari.8bit Frequently Asked Questions, last modified 29 November 2009, sections 1.1 (CPU clock rates), 1.5 ("What is the Atari 600XL?") and 1.11 (SALLY), faqs.org. Community reference for the production dates, the versions and their monitor ports, the Canadian 64K machines, the countries of manufacture and the end of production.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Robert DeWitt, "Inside Atari: Evolution of the XL Computers", Antic Vol. 3 No. 2 (June 1984), atarimagazines.com. Source for the 600XL driving only a television, the single 5 V DC supply and the PEEK(65527) values.
- ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 Atari, Inc., ATARI 600XL Computer Field Service Manual, FD100610 Rev. 1, October 1983: section 1 (theory of operation, RF modulator, power supply and figure 1-8, SIO, keyboard, controller, cartridge and PBI pin assignments), section 3 (symptom checklist), section 5 (schematic and its editor's note, parts list pp. 5-5 to 5-7) and section 6 (Tech Tip 20). Hosted on this wiki: Atari 600XL Field Service Manual (PDF).
- ↑ 5.0 5.1 5.2 5.3 5.4 Electronic Dimensions (San Luis Obispo, California), Service Manual for the Atari 800XL Computer, undated: theory of operation (memory, monitor output, keyboard, power supply). Third-party manual. Hosted on this wiki: Atari 800XL Service Manual (PDF).