18 Feb
2010
18 Feb
'10
9:57 p.m.
From: "Dave McGuire" <mcguire at neurotica.com>
Sent: Thursday, February 18, 2010 10:26 PM
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Subject: Re: Solderless breadboarding (was: Re: HP-IB,Amigo/cs80 was Re: hp
9153
On Feb 18, 2010, at 2:03 PM, Tony Duell wrote:
Yep, looks like a 68008. Cool stuff!
Yes, I have been using breadboards for more than 20 years and never
had a problem with them. Sure, you must not try to stick thick wires
into the contacts, and prevent lots of Amps running through the contacts.
Actually, I used a breadboard just two weeks ago for checking out the
UJT circuit used in the RK05 Exersizer ...
BTW, the article says it is an MC68008, so you did not need to count
24 pins (on one side) :-)
I developed a Euro-board sized 68000-based SBC running at 10 MHz
some 15 years ago for my StarShip simulation. Upgraded it to 68010,
but finally installed a VME based 68020 at 30 MHz.
The 68010 is pin compatible to the 68000, but if you are in OS stuff,
you have to modify some software if you are handling stack frames.
Those are not identical on the 68000 and 68010.
The 68000 SBC has 64k EPROM and 64k RAM (IIRC) and one 6850
on-board, as well as VPA, address decoding and a DTACK counter
circuit. If interested I could search the schematics and scan it.
How well designed it is/was, I do not know, but it works :-)
- Henk.
http://blog.makezine.com/archive/2010/02/
building_a_cpm_68k_computer_from_sc.html
Crazy, but I'm cheering for him! Retrotastic! :-)
Oh but WHY???
I don't want to discourge people from hacking, and making a 68K computer
(I beleive it's a 68008 processor, given the 48 pin package)
is certainly a fun project. But anyone who is interested enough to want
to do that, and has the abilities to design it, is capable of learning to
solder. Period. My guess is that if you knock the table, at least
one connection will
momentarily break, and the thing will crash. Built it on stripboard,
with the same rats nest of wires, and it'll probably work reliably.
Oh come on. I've been using these things for...jeeze, 33 years now.
They're not THAT unreliable. Seriously.
-Dave
--
Dave McGuire
Port Charlotte, FL