I had one of those, albeit for the S-100 bus, and found it functional but not as
useful as I'd originally hoped. It did save a little time, but all it really
saved was the time used to transfer a binary file into the target system's
memory.
The things the more generously appointed systems like the AIM or the Apple don't
allow you to do is (1) use address lines as device selects, (2) use ambiguous
decoding, (3) adapt the processor speed to the code being executed, (4) anything
else that involves changing system memory mapping or system timing to the target
application. That's what I mean by "their features get in your way."
They can compute anything you like, but the rate is dependent on their internals
rather than your target.
It happens I have the AIM schematic right here and what it indicates is that you
might have a little trouble finding a block of space for your target application
hardware in the memory map. The notes on my schematic indicate that I had to
use a modificaiton to open a block of space for an external application hardware
addition.
The Apple memory map available for expansion hardware is a mite trickier, i.e
each slot hin the backplane has different addresses available, yet each shares a
chunk of space intended for a ROM. It's not terrimbly difficult to work around,
but it means, at the outset, that you have to learn about the Apple rather than
the target.
Dick
----- Original Message -----
From: "Mike Ford" <mikeford_at_socal.rr.com>
To: <classiccmp_at_classiccmp.org>
Sent: Wednesday, July 18, 2001 1:39 AM
Subject: Re: Apple II for intro to microprocessors
> >That rendered the use of a dedicated develpment system with in-circuit
> >emulator
> >unnecessary, though not totally without potential merit.
>
> I bought something called a Romulator (something like that,
> http://www.romrocket.com/) that I could dump a file to over a serial link,
> and then it behaved in circuit exactly like an eprom. That with little bits
> of test software did just about everything I needed, along with a 4 trace
> scope to look at timing etc.
>
> What exactly is it that a microprocessor "system" like the Apple II or
> Aim65 can't do? (a paragraph not a page please)
>
>
>
Received on Wed Jul 18 2001 - 09:03:59 BST