The Gradiente Expert Plus is a Brazilian MSX 1 computer. It is composed of two parts: the main unit and the keyboard. Gradiente is a Brazilian consumer electronic products company. It is not suprising as the unit's design looks like a HI-FI system... Along with the Hot-Bit, the Experts were the only MSX systems available in Brazil. The first model (Expert XP-800) was in fact a clone of the National CF-3000.
It is a quite complete MSX 1 computer with two cartridge slots placed on the front panel and a numeric keypad. The system is powered by the MSX engine, a kind of super-chipset, gathering the CPU, video, input / output and audio functions.
The Expert can be used as videotext terminal (Telesp) with the TM-1 cartridge which includes a 1200 baud Modem, a serial interface and a phone socket...
The Expert Plus follows the Expert XP-800 (released in 1985) and the Expert GPC-1 (1986), which are quite similar. The Expert Plus was released (1989) at the same time as the Expert DD Plus which is the same system with a built-in floppy disk drive (720 KB).
Marcelo Ortega from Brazil adds:
The Expert Plus and DD Plus had a big incompatibility problem, that actually was not Gradiente's fault. Both machines used the MSX engine SMT chip, that made things easier to Gradiente assembly these computers, solving the bad contact problems of the socketed chips used in the previous Experts, and replacing three chips by one, but the MSX engine chip mapped the RAM to a internal secondary slot.
This was OK for the MSX standarts, but most brazilian software was written to run in Experts and Hotbits without secondary slots, and this resulted in many crashes.
The Expert users were also waiting for a MSX2 machine when the Plus was launched, and along with the common crashes, this made these machines not so popular.
The DDPlus uses a internal disk controller board that was quite similar to the external cartridge interfaces sold then. It also uses 16Kb for MSX DOS, resulting in 48Kb of ROM. The drive is very good (mine still works flawless !) but it was painfully slow.
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we can run zx spectrum 48k and one 128k programs at 6mhz please help