see below, plz.
Dick
----- Original Message -----
From: "Adrian Vickers" <avickers_at_solutionengineers.com>
To: <classiccmp_at_classiccmp.org>
Sent: Thursday, August 23, 2001 3:01 AM
Subject: Re: CBM 8032 SK
> At 01:56 pm 22/08/2001 -0600, Richard Erlacher wrote:
> >Hi, Adrian!
>
> Hi Richard! :)
>
> >If you're going to have "old" hardware, you're sooner or later going to
> have to
> >deal with DIY, since you can't hire out repairs of the sort you'll both
<snip>
>
> >Learning to operate an eprom programmer should be the least of your
> worries, not
> >because it's unimportant, but because it's easy.
>
> That makes sense. It's just that I've never used one before, so at this
> moment in time, I've not got any idea at all...
>
> >A big part of getting the appropriate equipment is learning enough to know
> >what's appropriate. Starting out small and simple is probably the best
> route.
> >Since we've established that you'll have to do no soldering to (1) replace
> the
> >EPROMs you lack, and (2) insert the CPU, you can probably breathe a sigh of
> >relief, in light of your apparent aversion to attempting such things at this
> >juncture. Perhaps that's just as well for now.
>
> Well... It's not that I *can't* solder, it's just that I don't seem to be
> very good at it for some reason. It may be that I've got a dodgy iron (I do
> need to get one with a much smaller tip if I'm going to start desoldering
> ICs), but a) The tip simply won't tin properly, b) It seems to take ages to
> warm anything up enough to get the solder flowing. For example, I must have
> spent 2 hours building a BBC 'B' monitor cable; and by the time the pin on
> the DIN plug got hot, it went a dodgy colour and the solder wouldn't flow
> onto it. I did eventually manage to get the cable going, but it was a hell
> of a struggle. It didn't help that I don't have a vice here, so I needed
> four hands at the time...
>
These are problems we all wrestle with and yet manage to get handled. Practice,
though it really doesn't make "perfect" does make better, and lack of it will
make you rusty, if you avoid it for a while. Wanting to avoid soldering and, in
general, dis/re-assembling things is wise. It can't always be avoided, however.
>
> >If you replace your missing CPU with one that's as old as the original,
> you'll
> >have little trouble. Back when the PET was built, there was only one type of
> >6502. That's the type you probably want. The CMOS versions were the ones
> that
> >came up with extra instructions, and, coincidentally, without the
> undocumented
> >ones that existed in the original.
>
> According to the datasheet (from Farnell) I was reading, the original
> didn't have a BRA instruction? That seems somewhat unlikely to me, but is
> it true?
>
I wasn't aware of a BRA instruction on the 6502. The CMOS parts and MOT had it
on a number of their later models ...
>
> >
> >You might visit www.6502.org to get a bit more info about this.
> >
> >If you want, I'll mail you an old 1 MHz 6502, but, since it involves going to
> >some trouble, please be sure that you've covered the other bases, so to
> speak,
> >so the effort won't be in vain. In general, it might not be a bad idea to
> find
> >someone in your area who has a working version of what you've got under
> study,
> >just to see if you know what it looks like when it's working right.
> Moreover, a
> >momentary parts swap can be VERY revealing.
>
> Hmmm - I've tried that one way, which revealed the duff CPU (and
> fortunately didn't fry the working machine), but I'm very leery of putting
> good parts in a fried machine (for much the same reasons Tony gives, and
> unashamedly based on his advice).
>
> Thanks anyhow! I'm starting to really look forward to poking around on this
> board - maybe there's (no?) hope for me yet...
>
> Cheers!
> Ade.
> --
> B-Racing: B where it's at :-)
> http://www.b-racing.co.uk
>
>
Received on Thu Aug 23 2001 - 08:36:40 BST