Contents |
Description
The Yamaha YIS-303 computer is a bridled CX5 with a different color.
This model was sold without any module, the printer port and half of the RAM are missing, the access to the expansion bus slot is blocked.
It was aimed at the Japanese market and features a simple Japanese keyboard with 70 keys. The power supply is internal. Two keyboard overlays were provided, one is gray, the other one is black.
| Brand | Yamaha |
| Model | YIS-303 |
| Year | 1983-11 |
| Region | Japan |
| Launch price | ¥49,800 |
| RAM | 16kB (in slot 0) |
| VRAM | 16kB |
| Media | MSX cartridges, side slot modules |
| Video | Texas Instruments TMS9918A |
| Audio | PSG (YM2149) |
| Chipset | Yamaha YM5214 |
| Keyboard layout | QWERTY/JP50on |
| Extras | |
| Emulation | ROM dump needed. See this thread for details |
Pictures
Specifications
The YIS-303 is a MSX1 with a Z80A from Sharp (LH-0080A). It supports all Yamaha modules, except the module HC-A602S from Victor, because the Video processor is not a TMS9928A.
To use the expansion bus as second cartridge slot, you need the Yamaha Single Cartridge Adapter CA-01.
The printer port is missing but we can add it by soldering a connector and the four chips near the cartridge connector on PCB.
We can also add 16KB RAM by soldering 4416 x2 and two 74LS244 instead the straps in the chip locations near at right. However, it is better to use a cartridge memory expansion (64kB or a MSX1 compatible memory mapper) to improve the compatibility. This prevents the main RAM from being split into two slots at address 8000h.
Slot Map
| Slot 0 | Slot 1 | Slot 2 | Slot 3 | ||||
|---|---|---|---|---|---|---|---|
| Page C000h~FFFFh | RAM | Cartridge Slot | Expansion Bus | Module Slot | |||
| Page 8000h~BFFFh | |||||||
| Page 4000h~7FFFh | Main-ROM | ||||||
| Page 0000h~3FFFh |
Connections
- DIN 41524 Monitor output
- Data Recorder connector
- 2 general connectors (Joysticks, Mouse, Paddle controllers, etc)
- 1 cartridge slot
- 1 module slot (left side, 60 pin connector without signals needed for superimpose)
- 1 expansion bus slot (back side, 2nd cartridge slot via CA-01 adapter) whose access is blocked
Links
- http://www.cx5m.net/ (Now the site is broken only some files still online), Archived version (2019 version, some files are missing), Another mirror (file-hunter.com)
- Yamaha YIS-503/303 flyer (Japanese)
- Blog post about the YIS-303 and 503 (Korean)