MSX Info pages

MSX 2(+) upgrades

MSX 2(+) conversion

Convert to MSX2+ by replacing the V9938 with a V9958 and add the F4 register required by Basic 3.0
Build a v9958 into a NMS8250/55
Build a v9958 into a NMS8280
Build a v9958 into a HB-700
Add the F4 register

Notes by JP Grobler on converting his NMS8250 to a MSX 2+:(with lots of help by Hans Oranje)
I got the v9958 vdp and had the v9938 removed & replaced with a shrinked dip socket at a TV repair shop (2Euro)

On the v9958 (connections were done on the chip itself!): 

    Pins 1, 4, 27 GND 
    Pins 21, 58 +5V 
    Capacitor 100nF between pin 21 and pin 20 (Analog GND).
I only had 27512 eproms and burned Basic 3 + Bios Sub roms into it.
On the 8250: 
    IC 119 = Main rom 
    IC 118 = Subrom 
    IC 117 = Diskrom
I only replaced IC 119 & IC 118 
    IC 118 socket: 
        Pin 1 (A15) is connected to +5V 
        Pin 27 (A14) is connected to +5V 
        Do not connect these pins of the eprom to the socket! 
        Add wire between Pin 1 (A15) and the unused 
        slot connector (MY) Pin 42 (5th from right) 
        Add wire between Pin 27 (A14) and the unused 
        slot connector (MY) Pin 41 (5th from right) 
    IC 119 socket: 
        Pin 1 (A15) is connected to +5V 
        Do not connect these pins of the eprom to the socket! 
        Add wire between Pin 1 (A15) and Pin 16 (GND)
Add the F4 latch: see Hans Oranje instructions

The source of these instructions is Hans Oranje!
These ROMS are published here with permission from Hans Oranje.
ROMS used by JP Grobler for MSX 2+ Basic 3.0

Hans Oranje not only adapted the MSX2+ ROMS to the international standard as used in dutch MSX machines, he also adapted for german MSX machines (for example keyboard mapping).
German MSX BASIC V 3.0 ROMS made for Franz Schiefer Austria and used in the NMS8280
Complete according to the SONY Technical Databoek

Dutch article how to perform the MSX2+ conversion
MSX2+ conversion

The instructions to convert the SVI 738 to MSX-2 also in english, combined the CUC dutch (translated) info and the danish/finnish info
Convert the SVI 738 to MSX-2

Convert Yamaha CX5M to MSX-2
Convert Yamaha CX5M to MSX-2

Dutch article: MSX 2+ ombouw: de hardware
MSX 2+ ombouw: de hardware

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