In article <[EMAIL PROTECTED] >, Richard Atkinson <[EMAIL PROTECTED]> writes
>Hullo Richard! Fancy seeing you here... I'm everywhere ;) But I have to admit it's a recent development, I missed my old CX5M but now I've spent a /lot/ on two CX5MII/128 models, I've started to use it properly! >The CX5MII (both 64K and 128K varieties) use the V9938 MSX2 graphics chip >and S3527 "MPS". You'd need to source the RP5C01 battery back-up chip from >somewhere and handle the address decoding yourself. Later MSX-ENGINE chips >had the RTC built-in. Sooo... there's not actually a space on the CX7 MB for the chip, then? I have the technical manual, but didn't see anything regarding the clock (as it's not installed in CX5M models), merely a reference to the battery cover which is on the base of the machine. So presumably the CX7 would have a later MSX-ENGINE and the battery pack in the base? >The V9938 was used for its 512 pixel text mode in the Yamaha machines; >hence they still only have 16K of VRAM like other MSX1 machines. If you >upgrade the VRAM to 128K using 4 41464 DRAM chips, and change the ROMs for >MSX2 ones, you should have all the MSX2 functionality you need. So all I need to do is upgrade my VRAM board? I've got the directions from that from Hans' site, but my soldering is decidedly strange! >The machine ROMs are regular MSX1 ROMs, and can be replaced with >regular MSX2 ROMs although I'm not sure how they'll react to not finding >an RTC present. Okay, that I was unsure about. I thought the CX7 had The Painter built in to the ROMs, or would start up with 'Yamaha' or something similar. I know it makes little difference! >You'd need to fashion an adapter yourself. It's possible but not really >necessary if you already have a CX5(M)(II). The audio amplifier design in >the Yamaha computers is better than that in some MSX2 computer schematics >I have seen. I use the RCA outs from the SFG, so that's not really an issue. Having said that MSX2 isn't of great importance anyway, just curiosity value to me - all I really want is to get one of my CX5MII/128s equipped with a disk drive! I could always get a cheap MSX2 off eBay - I think I saw a slightly damaged Philips NMS8250 go for £20-30 recently. A separate keyboard is useful just because of the layout of my studio... however, Yamaha YIS-805s aren't exactly common :( (and I don't know if they have space for the SFG. If they did I'd pay good money for one). Richard -- Classic Computers: Atari 800XL - Rescue on Fractalus! |\ _,,,---,,_ Yamaha CX5MII/128 - Music and MSX! Compaq 386 MIDI /,`.-'`' -. ;-;;, Apples? www.lovecraft.demon.co.uk/retrotech/ |,4- ) )-,_. ,\ ( `'::. Last found? Tandy 102 in my office drawer! '----''(_/--' `-'\_)Morticia -- For info, see http://www.stack.nl/~wynke/MSX/listinfo.html
