Gradiente Expert
 | |
| Type | home computer |
|---|---|
| Release date | December, 1985 |
| Discontinued | 1991 |
| Operating system | MSX BASIC, MSX-DOS, CP/M |
| CPU | Zilog Z80A/MSX Engine T7937A @ 3.58 MHz |
| Memory | 64 KiB–256 KiB (max.) |
The Expert, made by Gradiente Eletrônica (to date best known as a game console and Hi-Fi equipment company) was the second and last MSX home computer launched in the Brazilian market, in mid-1980s. Released one month after Epcom's Hotbit (just in time for 1985's Christmas), the Expert model XP-800 was an inferior clone of the National CF-3000, with a computer case resembling a stereo system, a detached keyboard with a proprietary connector, no caps lock LED and no reset key.[1]
The Expert XP-800 was followed by the Expert GPC-1 ("Gradiente Personal Computer") in 1987, and by Expert Plus and Expert DD Plus (a system with a built-in 720 KiB 3½" disk drive) in 1988. The Expert users waited in vain for a MSX2 machine, but Gradiente never produced it[1] and discontinued the MSX line in 1991.[2]
Versions XP-800/GPC-1
The two first versions had a graphite case and socketed chips, who provoked a chronic problem: when the machine heated, the chips frequently pulled out and the system "frozen". Also, the GPC-1, released in 1987, had a ROM slightly modified to solve an ASCII table compatibility issue with the other popular Brazilian MSX, the Sharp's Hotbit.[2]
Versions Plus/DD Plus
The two last versions had a black case and the problematic socketed chips was replaced by an ASIC one. Nevertheless, the RAM was mapped to a secondary slot and, although it was straight by the MSX standards, caused a lot of crashes with programs who searched for memory in the wrong place. It not contributed to add popularity to both Plus versions.[1]
Technical specifications
| CPU | Zilog Z80A (XP-800 & GPC-1) @ 3.58 MHz MSX Engine T7937A (Plus & DD Plus) @ 3.58 MHz |
| RAM | 64 KiB |
| VRAM | 16 KiB (Texas Instruments TMS9918) |
| ROM | 32 KiB |
| Keyboard | mechanic, 89 keys (with 4 cursor keys), number pad |
| Display | text: 40×24 rows; graphics: 256×192 pixels, 16 colours, 32 sprites |
| Sound | General Instrument AY-3-8910 (PSG), 3 voices, white noise |
| Ports | 2 joystick connectors, TV out, RGB monitor out, sound out, tape recorder connector, parallel port, 2 cartridge slots |
| Storage | tape recorder (1200/2400 bit/s) or one or two external disk drive (5¼", 360 KiB or 3½", 720 KiB) |
Peripherals
- DR-1 ("data-corder"): tape recorder
- JS-1: joystick
- MM-12: 12" monochrome monitor
- TA-1: TV adapter
- TM-1: 1200/75 bit/s modem with a RS-232C port
Notes
- ^ a b c Gradiente Expert Plus at old-computers.com
- ^ a b Template:Pt icon-The MSX in Brazil
External links
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