John, Before you develop another flash memory card have you tried using any of the higher end x266 or better CF cards that are designed for SLR photography to see if performance picks up. I’ve looked at the Kingston website for the basic (White Lilly) 4GB cards and they don’t specify a speed which makes me suspect that they are slow cards, Whereas the x266 CF card is specified at 40 – 45MB/Sec, and the x600 CF card is specified at 90MB/Sec. If it does turn out that the 8255 is the bottleneck would it not be worth developing a discrete logic replacement to try and maintain broad compatibility with the existing software (monitor) Base and CF card imaging process (cpmtools) Maybe others could comment on the differences between CF media and SD card media in terms of disk layout etc... Regards David Fry From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of John Monahan Hi Josh, I am toying with the idea of building a dual Micro SD card S100 board. I’m finding that the bottleneck in my 80386/80486 prototypes for MSDOS etc. is the 8255A driven dual IDE/CF board. Did you get the SD card working with CP/M on your 8080 board. Any idea how “fast” it is relative to a CF card for data access. I’m worried the interface is in fact slower that an 8255A. Perhaps a large Flash RAM board would be a better approach. What do you think. John No virus found in this message. -- |