You're certain right . . . it is a dead horse . . . killed by the insistence
that 750 ns < 250 ns.
Dick
-----Original Message-----
From: allisonp_at_world.std.com <allisonp_at_world.std.com>
To: Discussion re-collecting of classic computers
<classiccmp_at_u.washington.edu>
Date: Monday, April 12, 1999 7:59 AM
Subject: Re: stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4
floppies)
>> I didn't want to descend into the gate-level details of the CPU, but
merely
>> to count clocks for comparison's sake.
>
>Since the clocks are applied in such a different fashion the comparison is
>meaningless.
>
>> clock ticks to access memory while a 6502 took only one. As I've said in
>> previous posts, the comparison at the memory bandwidth level came out in
>
>Meaningless unless that is a particular requirement of an application
>HARDWARE.
>
>> the fastest commercially available Z-80 with the fastest commercially
>> available 6502, the 6502 will win by a wide margin EVERY time. Compare
the
>> Z80H (1983 or so) with the Synertek SYC6502C (1979) and you'll see that
>> 8 MHz Z-80 can't be counted on to win the race. If you like, you can
>
>Your dreaming again. Seriously weve beat the dead horse and it's time to
>quit. The 6502 is a good cpu but the comparisons are getting silly.
>
>If you really want to compare archectecture I'll take the T-11 (PDP-11 on
>a 40 pin dip) _at_7.5mHZ and blow the both out of the water. here a part
>from The same era that has all the addressing modes of the 68k and then
>some and can use memory like the 6502 or z80 with its registers. Things
>like position independent code, relative addressing and two address
>structure are all there. the problem is the arguement is specious as I
>can also use the CMOS PDP-8 part to put up as good a battle of who wins.
>And getting a PDP-8 into a FPGA has been done as well.
>
>> compare the 8 MHz Z-80H with the Rockwell 65C102, which takes a 4x clock.
>> Now it takes 4 clock ticks at 16 MHz to execute a bus cycle of any type.
>> Feed it an 8 MHz clock, it will still outdistance the Z-80H.
>
>YEs and the z180S part takes a 33mhz clock, whats the point? CLOCKS and
>counting them is meaningless unless they mean something comparable.
>
>> I remember what it was like trying to get delivery on 2147's back in
>'81. I
>
>There were peole sellign 4kx1 22pinparts at near firesale prices compared
>to 2147 and were near 65ns. They were of the pseudo static three voltage
>generation but the y were cheap.
>
>> machines of the early '80's. That might be worth a look. What I want is
a
>
>Smallc had limited optimization. I've used it for other cpus and it's fat.
>I would ahve guessed that was ported to near everything but it's not a
>production compiler though I guess it could be used as one.
>
>> I recently bought a couple of single board dedicated boards, and found
that
>> they had the 4 MHz Rockwell CMOS parts on them. I didn't think I'd ever
see
>> something like that in the scrap box. Oh well, once I've figured out the
>> memory map, they'll be useful for 1-of's.
>
>I have 4 or 5 board from telvideo 905/955 terminals and they have 65C02s
>from rockwell on them. I also have a trackstar 128 (APPLE II for PC) that
>has two 65C02s.
>
>
>Allison
>
>
>
>>
>> >Allison
>> >
>>
>
Received on Mon Apr 12 1999 - 09:43:40 BST