bmw@isgtec.UUCP (Bruce Walker) (03/16/90)
I am responding to a very provocative article here. I could say a lot on the topic but I won't 'cause this ain't the forum. If there was a comp.product.design, I'd cross-post to that. But I'll just say this: In article <2798@isc-br.ISC-BR.COM> jimc@isc-br.ISC-BR.COM (Jim Cathey) writes: > In article <833@gold.GVG.TEK.COM> grege@gold.GVG.TEK.COM (Gregory Ebert) writes: > >A good candidate is the WD37C65 from Western Digital. > > I myself don't think too much of the uPD765 derived controllers, which > describes nearly everything new that's available. They are much less flexible > than the Western Digital (177x, 179x, 279x) series of parts. The 'disk-format' is less flexible, but the disk interface logic is a lot more flexible on the 765-type chips. Eg: the head unload and head stepping rate timers are programmable with finer resolution. > If you want > a format that isn't used by the PC you're out of luck with the 765. The WD > chips would allow you to do a 1-sector-per-track format if you wished My opinion is that it is a very good thing that all 765-written diskettes are readable on every other floppy controller. Remember the CP/M world? Of course experimenters are free to do whatever they wish, but it would be a very brain-damaged commercial product that came out with a "new" floppy format these days. > Also, the 765 is a pain to talk to in software when compared to the older WD > chips. Formatting is slightly easier, though, albeit very inflexible. Agreed. The driver writer will have his hands full the first time. But this is not a big point. And you only have to get the *logic* right once then you can port the skeleton around and translate into whatever machine you're targeting. I wrote my 1st driver for the 765 on a 6800, then ported the same code onto a Z8, Z8000 and a Z80 system. The comments remained the same, only the opcodes changed :-) > It is > possible to write a much faster disk copier using the WD chips than the 765 > series. Sorry, I don't buy this. I achieved 1:1 interleave with all my drivers and you can't do better than that. > Are we going to be forever innundated with endless clones of > second-rate parts (8250, 765) just because of that crummy IBM PC? a) the 765-family is *not* 2nd rate (see above) b) yes, I'm afraid the rest is true. I personally have been inconvenienced a lot by the s/w and h/w designs in the PC. But it's a living :-) -- Bruce Walker ...uunet!utai!lsuc!isgtec!bmw bmw@isgtec.uucp "What is the mind? No matter. What is matter? Never mind." -- Homer Simpson ISG Technologies Inc. 3030 Orlando Dr. Mississauga. Ont. Can. L4V 1S8