| Type: | home computer |
| Released: | December 1985 |
| Discontinued: | 1990 |
| Processor: | Zilog Z80A |
| Memory: | 64 KB - 4096 KB (max.) |
| Os: | MSX BASIC, MSX-DOS, CP/M |
| Compatibility: | MSX |
| Expert | |
| Aka: | Expert XP-800 |
| Manufacturer: | Gradiente Eletrônica |
| Successor: | Expert GPC-1 |
| Cpuspeed: | 3.58 MHz |
| Graphics: | TMS9918 |
| Sound: | AY-3-8910 |
| Memory Card: | Cassette tape, cartridges, floppy discs |
The Expert (or Expert XP-800), 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 the mid-1980s.[1]
It was presented to the public at the 5th International Computing Fair, nicknamed "Informatica '85".[2] The event took place at Anhembi Convention Center in the city of São Paulo from September 23 to 29, 1985.[3] At the announcement, the computer was priced 65 ORTN s.[4]
Its market release date was 1 December 1985, one week after Epcom's Hotbit, just in time for 1985's Christmas and with a massive media campaign on magazines, newspapers and TV. In the newspapers ads the initial offer price was Cr$ 4,640,000, or US$470 by the value at the time,[5] or US$1,165 by the end of 2021.
The machine was a 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, although the soft-reset could be achieved by pressing simultaneously the keys Shift + Control + Delete, while a hard-reset could be achieved by pushing in either of the cartridge slot covers, if they were free.[6] [7]
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 KB 3" floppy disk drive) in 1989.[8]
The Expert users waited for an MSX2 machine, but Gradiente never produced it and discontinued the MSX line in 1990.
The two first versions had a graphite case and socketed chips, which caused a chronic problem: when the machine heated, the chips frequently pulled out and the system "froze". 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, Sharp's Hotbit.
The last two versions had a black case and the problematic socketed chips were replaced by an ASIC. 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 did not contribute for the popularity of any of the Plus versions.[8]
These machines used the MSX-Engine T7937A instead of the Z80A CPU of previous models.
| CPU | Zilog Z80A (XP-800 & GPC-1) @ 3.58 MHz MSX-Engine T7937A (Plus & DD Plus) @ 3.58 MHz | |
| VDP | TMS9918 | |
| RAM | 64 KB | |
| VRAM | 16 KB | |
| ROM | 32 KB | |
| 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 floppy drives (5", 360 KB or 3", 720 KB) |
