Atari 2600 Jr
 | |
| Atari 2600 Jr. | |
| Specifications | |
|---|---|
| Manufacturer | Atari Corporation |
| Type | Home video game console |
| Released | 1986[1] |
| Intro price | Advertised at under US$50[2] |
| CPU | 6507 (A2)[3] |
| Memory | 128 bytes, inside the 6532 (A1)[3][4] |
| Storage | ROM cartridge |
| Display | TIA (A3) |
| Sound | TIA, 2 channels |
| OS / Firmware | None |
| Predecessor | Atari 2600 (CX2600A) |
The Atari 2600 Jr. is the cost-reduced version of the Atari 2600 that Atari Corporation introduced in 1986, in a smaller case styled like the Atari 7800.[1][2] Atari advertised it at under US$50 with the slogan "The fun is back!". It plays the same cartridges as every other 2600.[2][1]
The 2600 Jr. runs on the same three main chips as the earlier models: the 6507 processor, the 6532 RAM-I/O-timer and the TIA. Atari's field service manual for the CX2600 and CX2600A does not cover it.[5] Its board is different, so the designators on the Atari 2600 guides do not apply to it.
Versions
[edit | edit source]| Version | Description |
|---|---|
| "Short rainbow" | The first 2600 Jr., with a short rainbow stripe on the metal faceplate; silver or red box[1] |
| Rev. A ("long rainbow") | Almost the same, with a wider rainbow[1] |
| All black | No silver band, a small rainbow and white lettering; AtariAge believes it was sold only in Ireland[1] |
| PAL | European consoles; later ones were sold with a joypad[2] |
TBA's UAV manual mentions a rare "one-chip" 2600 Jr. besides the usual three-chip NTSC board.[6]
Hardware
[edit | edit source]
The Jr. is a single board. On the photographed NTSC board the main parts are as below; the J6 button connection is from the PAL schematic.[3][7]
| Location | Part | Marking on the photographed board |
|---|---|---|
| A1 | 6532 RAM, I/O and timer | UM6532 |
| A2 | 6507 processor | UM6507 |
| A3 | TIA | UM6526N |
| A4 | 4050 hex buffer | CD4050 |
| A5 | Transistor array in the RF modulator | CA3086 (RCA) |
| VR1 | 7805 regulator, on a copper pad at the front left | 7805 |
| R9 | Trimmer beside the reservoir capacitor | |
| J1, J3 | Controller ports | |
| J2 | Power input jack | |
| J4 | RF output | |
| J5 | Cartridge connector | |
| J6 | Connector for the flexible cable to the SELECT and RESET buttons |
The same designators appear on Jerzy Sobola's redrawn schematic of a PAL 2600 Jr. board (titled "Motherboard C012283 rev. B"). On it, R9 (500 kΩ) is the trimmer on the TIA's colour-adjust pin (pin 10), the 4050 at A4 buffers the luminance and sync lines and is also used in the reset circuit, and A5 is an LM3086 in the modulator.[7] TBA's manual also says the 4050 cannot be removed from a Jr. because the reset circuit uses it.[6] The NTSC board in the photograph has an unpopulated area with footprints for Q5, Y2, L9 and C46 to C48, which on the PAL schematic are the 4.43 MHz colour-carrier parts.[3][7]
Power
[edit | edit source]The console runs from an external AC power adaptor, as Atari calls it in the owner's leaflet; the leaflet warns that any other adaptor can damage the console.[8] On the PAL schematic the input at J2 has a 0.1 µF capacitor (C2) and a 2200 µF reservoir (C26); the power switch S4 follows, then a 4.7 µF capacitor (C37) and the 7805 regulator VR1. The power LED DS1 is fed through R57 (750 Ω).[7]
TBA's manual says some Jr. consoles have nothing holding the regulator to its copper cooling pad, and advises soldering the tab down or fitting a screw through the board.[6] The regulator on the photographed board is held by a screw and nut.[3]
Controls
[edit | edit source]The owner's leaflet names the power switch, the TV TYPE switch (colour or black-and-white), the left and right difficulty switches and the CHANNEL SELECTOR (2 or 3) on the back.[8] SELECT and RESET are push buttons on the top case, joined to the board by a flexible cable that has to be unplugged before the top case comes off.[9][6]
Capacitors
[edit | edit source]Console5's list for the NTSC Jr. and the PAL schematic agree on the designators and values of the electrolytics: C26 is 2200 µF and C20, C27, C29 and C37 are 4.7 µF. Console5 gives the ratings, 16 V for C26 and 35 V for the others, and notes that C27, C29 and C37 are ceramic capacitors on some revisions. The sound-carrier capacitors C53 and C54 are 820 pF polystyrene parts.[10][7] Details are on the Atari 2600 Jr Capacitor Replacement Guide.
Video output
[edit | edit source]The Jr. has RF output only. Composite and S-video mods for it, including the UAV, are on the Atari 2600 Jr Composite Video Mod page.[6]
Documentation
[edit | edit source]- Atari 2600 Jr Documentation: the owner's leaflet and the PAL schematic.
- Atari 2600 Jr. owner's leaflet, C026260-001 (1986).
- PAL 2600 Jr. motherboard schematic, redrawn by Jerzy Sobola (2000).
- The Atari 2600 and 2600A Field Service Manual covers the earlier models only, but its chip pinouts apply to the same three LSI chips.[5]
Gallery
[edit | edit source]-
Top case removed, RF shield in place -
NTSC board with the shield removed -
PAL board schematic, sheet 1
.jpg)
.png)
Related pages
[edit | edit source]- Atari 2600 Jr General Maintenance
- Atari 2600 Jr Troubleshooting Guide
- Atari 2600 Jr Capacitor Replacement Guide
- Atari 2600 Jr Composite Video Mod
- Atari 2600
- Atari 7800
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 AtariAge, "Atari 2600 Consoles and Clones", entries "Atari 2600 Jr.", "Atari 2600 Jr. Rev. A" and "Atari 2600 Jr. - Black".
- ↑ 2.0 2.1 2.2 2.3 Wikipedia, "Atari 2600", section "1986 model" and the 1986 entry in the timeline. en.wikipedia.org. Used for history and the advertised price.
- ↑ 3.0 3.1 3.2 3.3 3.4 Evan-Amos, photograph of an NTSC Atari 2600 Jr. motherboard, Wikimedia Commons, public domain; designators and chip markings read from the image. Hosted here as File:Atari-2600-Jr-Motherboard-Flat.jpg.
- ↑ Steve Wright, Atari, Inc., Stella Programmer's Guide, 3 December 1979: 128 bytes of RAM in the 6532. Hosted here as Stella Programmers Guide.
- ↑ 5.0 5.1 Atari, Inc., Video Computer System Field Service Manual, Domestic Model 2600/2600A, FD100133 Rev. 02. Hosted here as Atari 2600 and 2600A Field Service Manual.
- ↑ 6.0 6.1 6.2 6.3 6.4 The Brewing Academy, Bryan's Ultimate Atari Video Rev. D Instruction Manual, revision 1.94, 23 March 2021, "Atari 2600 Jr." (p. 12). PDF from thebrewingacademy.com.
- ↑ 7.0 7.1 7.2 7.3 7.4 Jerzy Sobola, redrawn schematic "Motherboard C012283 rev. B, Atari 2600 Game Console", sheet 1 of 2, 8 September 2000 (PAL 2600 Jr.). Hosted here as File:Atari 2600 Jr PAL motherboard schematic (Jerzy Sobola).png.
- ↑ 8.0 8.1 Atari Corp., Atari 2600 owner's leaflet for the 2600 Jr., C026260-001, 1986. Hosted here as File:Atari 2600 Jr Owner's Manual C026260-001.pdf.
- ↑ David Savery, "Atari 2600 composite video mods", R3UK, 2004, updated 2008 (a UK PAL "Revision A" Atari Jr.). Community project write-up.
- ↑ Console5 TechWiki, "Atari 2600", "Capacitor Info & Refresh Kit Installation", NTSC Junior lists. Community list read from boards, not manufacturer documentation.