Panasonic FS-A1WSX
 | |
| FS-A1WSX from the front (photograph by Florian Schäffer, CC BY-SA 4.0) | |
| Specifications | |
|---|---|
| Manufacturer | Matsushita Electric Industrial (Panasonic) |
| Type | MSX2+ home computer |
| Released | October 1989[1] |
| Intro price | ¥69,800[1] |
| CPU | Z80A-compatible in the T9769 MSX-Engine, 3.58 or 5.37 MHz[1] |
| Memory | 64 KB RAM, 128 KB video RAM, 16 KB SRAM[1] |
| Storage | 3.5-inch drive, 720 KB[1] |
| Display | Yamaha V9958[1] |
| Sound | PSG, MSX-MUSIC[1] |
| Power | AC 100 V ±10 %, 50/60 Hz[1] |
| OS / Firmware | — |
| Predecessor | Panasonic FS-A1WX |
| Model no. | FS-A1WSX |
The Panasonic FS-A1WSX is an MSX2+ computer that Matsushita Electric Industrial released in Japan in October 1989 under the Panasonic name, at ¥69,800, as the successor of the Panasonic FS-A1WX. The MSX Resource Center lists its changes from the WX as an added S-video output, colour printing from the word processor with Panasonic's FS-PC1 printer, and the data recorder connection moved into the RGB connector.[1]
Specifications
[edit | edit source]| Item | Figure |
|---|---|
| CPU | Z80A-compatible in the T9769 MSX-Engine; 3.58 MHz or 5.37 MHz |
| RAM | 64 KB main, 16 KB SRAM |
| Video | Yamaha V9958, 128 KB video RAM |
| Sound | PSG, MSX-MUSIC |
| Drive | 3.5-inch, 720 KB |
| Interfaces | Two cartridge slots (top and rear), printer, two general-purpose ports, RGB with data recorder, S-video, composite video and audio, RF |
| Supply | AC 100 V ±10 %, 50/60 Hz |
[1] The MSX Resource Center gives the MSX-Engine as a Toshiba T9769 model B or C. Unlike earlier Panasonic MSX2 and MSX2+ machines, holding DEL during start-up no longer bypasses the built-in firmware; only the front-panel switch does. Loading and saving through the RGB connector needs a special cable, and the volume is much lower than on a normal tape interface.[1]
Hardware
[edit | edit source]No schematic, parts list or service document for the WSX itself has been found. The closest is the documentation for the Panasonic FS-A1WX: the PDF of BABAX's WX schematic carries the internal title "FS-A1WX,FX.WSX_SCHEMATIC_04.CE3", but the drawing itself is of a WX board.[2] Two parts are known to match the WX:
- The transformer. An owner read the marking DDT5U7J02Z-W on a failed WSX transformer, with a four-pin connector to the board; the WX parts list gives the same part number for T1, and the WX power unit also uses a four-pin connector.[3][2][4]
- The drive belt: rubber, 0.3 mm thick, 58 mm in diameter and 3 mm wide, as on the WX.[1][5]
The drive is a belt-driven Matsushita EME-213MA.[6] The WSX's S-video output and RGB-connector cassette interface mean the board differs from the WX's at least in the video and connector circuits.[1]
The MSX Resource Center says RAM can be raised to 256 KB with a little soldering and to 512 KB with a more complicated modification.[1]
Known problems
[edit | edit source]- The drive belt perishes. In a 2015 repair, melted rubber was stuck to every pulley and had to be cleaned off before a new belt would read discs.[6] See Panasonic FS-A1WSX General Maintenance.
- An imported WSX switched itself off and on until the case was tapped; forum members pointed to dry joints in the supply, the transformer connector and the power switch.[7]
- A failed internal transformer has been reported.[3]
- The MSX Resource Center advises against alkaline backup cells because they leak sooner or later, and recommends lithium cells or Eneloop rechargeables.[1]
Repair guides
[edit | edit source]- Panasonic FS-A1WSX General Maintenance
- Panasonic FS-A1WSX Troubleshooting Guide
- Panasonic FS-A1WSX Capacitor Replacement Guide
The Panasonic FS-A1WX guides carry the circuit-level detail; the WSX guides cover what is known to be specific to the WSX and refer to the WX for the rest.
Related pages
[edit | edit source]- Panasonic FS-A1WX, the predecessor, and the Panasonic FS-A1WX Documentation
- Panasonic FS-A1ST, the turbo R in the same style of case
References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 Panasonic FS-A1WSX, MSX Resource Center wiki, 14 August 2026—link(accessed 2026-10-21) Community page: released October 1989 in Japan at ¥69,800 as the successor of the FS-A1WX; the cassette port is combined with the RGB connector (loading and saving work with a special cable, at a much lower volume than a normal tape interface); S-video output added; colour printing with the Panasonic FS-PC1 printer; 64 KB RAM in slot 3-0 and 16 KB SRAM; 128 KB VRAM; Yamaha V9958; PSG and MSX-MUSIC; Toshiba T9769 model B or C and a Mitsubishi gate array given as M50014; firmware bypassed only with the front switch, not the DEL key; RAM can be raised to 256 KB with a little soldering and to 512 KB with a more complicated modification; drive belt rubber, 0.3 mm thick, 58 mm diameter, 3 mm wide, sold as Panasonic FW-U1P501J; the gallery shows the EME213MA drive, with the caption that its alignment sensor must be moved during a belt change; connections RF, audio and composite video, RGB output and data recorder port, S-video, printer, two general-purpose ports, two cartridge slots, mains plug for AC 100 V ±10 %, 50/60 Hz; recommended backup batteries lithium or Eneloop, alkaline advised against "because they leak one day or another".
- ↑ 2.0 2.1 BABAX, Panasonic MSX2+ FS-A1WX Schematic, revision 04a, 9 August 2014, traced from a board marked DFUP0250ZAU1a (serial 8KCKB01501), with parts list "FS-A1WX パーツリスト PARTS LIST", 5 August 2014, revision 02. Parts list: IC1 CXA1145M; IC2 TC8566AF; IC3 M60014-0140FP (the drawing labels it "FX/WX gate array"); IC4 T9769A or B; IC5 YM2413; IC6 LM324; IC7 MC34063; IC10 MN1280R; IC11 to IC14, IC22 and IC23 MB81464-12; IC17 and IC18 MB834000; IC19 and IC20 MB8464-15L; IC21 and IC24 81C4256 shown in brackets as unfitted; IC28 79L12; IC29 78L12; Q11 2SA1598; D8 SB540; X1 16.00 MHz; X2 32.768 kHz; X4 21.47727 MHz; T1 transformer DDT5U7J02Z-W; V1 battery 1.5 V × 2; RY1 relay SZ-5; CN1 power in, CN6 RGB (8-pin DIN), CN7 cassette (8-pin DIN), CN13 drive. The drawing labels IC8 V9958 "MSX-VIDEO II"; the parts list gives "V9938 E-VDP-II". The list notes that ROMs and transistors can differ between production lots. Community reverse-engineered drawing, not a Panasonic document. Hosted as File:Panasonic FS-A1WX schematic and parts list (BABAX, Rev 04a).pdf.
- ↑ 3.0 3.1 Help with the FS A1WSX internal transformer, July 2004—link(accessed 2026-10-21) Niles: the WSX's internal transformer had failed; it is marked "DDT5U7J02Z-W", and its connector to the main board has four pins. NYYRIKKI: probably the same transformer as in the A1WX (round, about 11 W, he thought); he had his rewound for 220 V by a local repair shop and later used it in an A1ST, which originally has a different transformer and connector; the usual problems of the Panasonic FS series are the drive belt, the power supply and a worn keyboard membrane. Sonic_aka_T: his FS-A1GT's three-pin CN1 measured 19.2 V AC from pin 1 to each of pins 2 and 3, off load, on 120 V mains.
- ↑ FS-A1WX circuit diagram, figure 8, "power unit", printed page 63: AC 100 V through the double-pole power switch to transformer T1; a four-pin connector to the board (pin 2 to ground); D1 and D2 into C57 and C34 (25 V, 3300 µF each); DC/DC converter IC7 (MC34063) with switching transistor Q11 (printed "2SA598"), current-sense resistor R96 (0.2 Ω), R97 and R98 (100 Ω), R113 (22 Ω), R114 (68 Ω), timing capacitor C59 (330 pF), catch diode D8, feedback resistors R99 (3.9 kΩ) and R101 (1 kΩ), C54 (0.1 µF) and R95 (330 Ω), inductor L5 to the +5 V (Vcc2) line with C53 (10 V, 3300 µF), then L6 to +5 V with C70 (6.3 V, 470 µF); pin 4 through D7 and D6 to C36 and C35 (35 V, 470 µF) and the 78L12 (IC29, +12 V, with C56 0.1 µF) and 79L12 (IC28, −12 V, with C55 50 V 1 µF) regulators. Lower half: the clock oscillator (IC9 TC40H004P, X2 32.8 kHz), reset IC10 (MN1280R), the 3 V battery connection through D9 and D10, and the backup switching transistors Q8 and Q9. Hosted as File:Panasonic FS-A1WX circuit diagrams (pages 55 to 64).pdf. Reproduced as File:Panasonic FS-A1WX power supply circuit (figure 8).png.
- ↑ Panasonic FS-A1WX, MSX Resource Center wiki, 14 August 2026—link(accessed 2026-10-21) Community page: released 21 October 1988 in Japan at ¥69,800; almost the same as the FS-A1FX but with MSX-MUSIC and a Japanese word processor; 64 KB RAM in slot 3-0 and 16 KB SRAM; 128 KB VRAM; 720 KB 3.5-inch drive; Yamaha V9958; PSG and MSX-MUSIC; Toshiba T9769 model A or B and a Mitsubishi gate array given as M50014; TC8566AF floppy controller; Z80A in the MSX-Engine switchable from 3.58 MHz to 5.37 MHz through I/O ports; front switch to stop the built-in firmware starting; Ren-Sha Turbo (auto-fire) slider; main RAM can be expanded to 256 KB internally; drive belt rubber, 0.3 mm thick, 58 mm diameter, 3 mm wide, sold as Panasonic FW-U1P501J; connections RF, audio and composite video, RGB, data recorder, printer, two general-purpose ports, two cartridge slots (one on top, one at the back), mains plug for AC 100 V ±10 %, 50/60 Hz; recommended backup batteries lithium or Eneloop, alkaline advised against "because they leak one day or another"; also sold as the FS-A1WXH bundle with the FS-PA1 thermal printer.
- ↑ 6.0 6.1 Panasonic「FS-A1WSX」ゴムベルト交換, 29 November 2015—link(accessed 2026-10-21) The FS-A1WSX's drive is a belt-driven Matsushita EME-213MA. Procedure: remove seven Phillips screws from the underside and lift off the top, unplugging two connectors; remove the four screws holding the drive base and unplug the flat cable; remove the drive's four screws (the screws on the black plate can stay); remove the screw and the white plastic part, and photograph the position of the sensor mounted with the board beside it first, because it is easy to refit wrongly; change the belt; reassemble and test with CALL FORMAT. Melted rubber was stuck to every pulley; left in place, it stops a new belt reading discs; isopropyl alcohol removes it cleanly. The author used a Daiso "D-009" hair band (small size) as a substitute belt, and laid clear tape in the guide groove under the black pulley to stop the belt slipping into the gap between the pulley and the metal frame.
- ↑ FS-A1WSX powering off/resetting until I tap the machine, December 2023 to January 2024—link(accessed 2026-10-21) pawlicker: an imported FS-A1WSX, run from a 120 V to 100 V step-down adapter, switched itself off and on until the top of the case was tapped; reflowing the power switch did not help. sd_snatcher: not a common fault on these machines; suspect broken solder joints or bad capacitors in the supply, the internal connector to the transformer, or the power switch; Panasonic, Sony and Sanyo MSX machines run on about 127 V 60 Hz without a step-down transformer, unlike Toshiba ones. NYYRIKKI: if the power LED reacts to tapping, it is the supply; measure the voltages. maxis: a typical sign of a dry joint; inspect every joint with magnification. Pencioner: oxidised contacts inside the switch itself can cause it and make the switch hot. Wierzbowsky: inspect the board from both sides, starting with the AC power connector and the AC-DC section. MSXcri: his FS-A1WX's reset button sometimes stuck down, making the machine reset continuously until the button was freed.
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