I have a wonderful magazine, EE Times, September,
1988, a special on the 30th anniversary of the
integrated circuit. It's mentioned that the first
design of the 6800 was a yield catastrophe, and
essentially it was completely relaid out from scratch
before it was actually released. Other interesting
stuff, for example, the PDP-8 inspired Ted Hoff on the
design of the 4004.
--- Richard Erlacher <edick_at_idcomm.com> wrote:
> Here's a page with some interesting "miscellaneous
> trivia" including the
> transistor count, etc. of the 6800 ... I remember
> that came up as a question
> some time back.
>
> more regarding the 6502 below ...
>
> Dick
>
>
<
http://www.motorola.com/content/0,1037,121-286,00.html>
> ----- Original Message -----
> From: "Pete Turnbull" <pete_at_dunnington.u-net.com>
> To: <cctalk_at_classiccmp.org>
> Sent: Friday, June 07, 2002 5:17 PM
> Subject: Re: [CCTECH] Interesting tidbit on 6502
>
>
> > On Jun 7, 13:05, Richard Erlacher wrote:
> > > You may be confused about this. I don't know of
> a single NMOS 6502 that
> > > didn't adhere to the MOS-technology instruction
> set. There's no telling
> > > whether that included the undocumented opcodes,
> but since Synertek and
> > > Rockwell used the MOS mask set, I suspect there
> was no difference. The
> > later
> > > Synertek parts may have been different since
> they shrank the die and got
> > a bit
> > > more speed, offering a 4 MHz 6502-C, which was
> an NMOS part and worked
> > > perfectly in NMOS-targeted systems that didn't
> work with the later CMOS
> > parts.
> >
> > There certainly were differences between the sets
> of undocumneted opcodes
> > from different manufacturers of 2MHz 6502A parts.
> I remember one or two
> > "clever" bits of software that failed on some BBC
> Micros for that very
> > reason. Sean is absolutely right to avoid
> undocumented codes.
> >
> I don't know that I have any of the NMOS 2 MHz 6502A
> parts any longer, but I'm
> planning a complete re-read of the undocumented
> opcodes and their behavior
> sometime soon. I figure I can do it with a
> serial-port connected 805x family
> part, with ports 1 and 2 monitoring the address
> lines, port 0 on the data bus,
> and port 3 interacting with the clocks, R/W, sync,
> rdy, and irq lines. A fast
> enough part can download the things it "sees" via
> the serial port and can hold
> the circuit under test in WAIT until the data is
> uploaded to the host. A
> timer can drive the Phase-0 clock. That should
> provide ample detail about
> what, exactly happens on every opcode without a lot
> of fiddling with a logic
> analyzer. It'll be a while, though ...
> > --
> > Pete Peter Turnbull
> > Network Manager
> > University of York
> >
>
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Received on Fri Jun 07 2002 - 22:21:04 BST