stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4

From: Jerome Fine <jhfine_at_idirect.com>
Date: Tue Apr 13 08:35:54 1999

>Pete Turnbull wrote:

> I started on the Z80, then 6502, followed by ARM, 68K, 6809, 8048, PDP11,
> MIPS in no particular order. I still like the Z80 and 6502, but the ARM is
> one of my favourites. I've never written any serious code for x86, and
> what I've seen of the architecture fills me with loathing ;-)

Jerome Fine replies:

I had an OLD 286 back when the 486 was already old. Just for fun,
I re-wrote some PRIME number programs from VMS in FORTRAN
to Turbo C. The most fun was in taking the inner loop routines and
converting to assembler. I learned a lot about the x86 architecture.
While at least I had a lot more memory immediately available to
save the tables (about 400 Kbytes - much more than on the PDP-11)
the addressing reminded me a bit of the old CDC 6600. I agree
that the old x86 memory usage is very bad for sizes more than
64 KBytes, but I seem to get the impression that under the 32 bit
memory map on the 586 machines (I have not done ANY programming,
so I am probably wrong) when in W95/98, there is a substantial address
space available. Am I wrong?

Sincerely yours,

Jerome Fine
RT-11/TSX-PLUS User/Addict
Received on Tue Apr 13 1999 - 08:35:54 BST