Re: Commodore 8296GD

Great to find an inspiring piece of hardware.

I could be wrong but aren't programs for the B series machines like the
European 600/USA B128 incompatible with the 8296?  I thought that the 8296
was more like the PET 8000 series with extra RAM.

But I know little about the 8296, having only seen a dead one that did not
power up.  They look exactly like the high profile B series machines such
as a the USA CBM 256-80  / European 720

I may have an 8296 diagnostic somewhere.  Does the 8296 have an 8088
co-processor?  Now that would be something rare.

Bill

On Fri, May 26, 2017 at 10:59 PM, MiaM <mia@plea.se> wrote:

> >> One more thing - the register is not cleared by a reset. So if you map
> >> out the BASIC ROM, then press the reset switch, the computer will not
> >> restart because the BASIC ROM is still mapped out. Only switching it
> >> off and on will work. Quite sloppy design, because resetting the
> >> computer while performing some graphics operation may render it
> >> unusable unless physically turned off (losing all RAM contents).
> >
> >The register 74LS174 has a /CLR input at pin 1. I see a track near this
> pin. On the other end of this track is >pin 2 (/RES) of 6545. So the
> question is, isn't that connected?
>
> The 8296 has two different reset lines, one for the CRTC and another for
> everything else. Both goes low for a while when you turn the power on, but
> the reset button is only connected to the line that doesen't reset the
> CRTC.
> That's the reason why you can see the screen contents for a short while
> after you have pressed the reset button.
>
>
> P.S. isn there any progress on the reverse engineering of this card? I'd
> really like to build one myself.
>
> P.P.S.
> In case you wounder how I ended up on this list: I just aquired a PET 600,
> which is basically a rebranded 8296. It has swedish (same as finnish?)
> ROM's
> for keyboard layout and character generator, but the keyboard were missing.
>
> I also got an empty CBM II keyboard case. Currently I have rewired the
> matrix on an old "FACIT" terminal keyboard, made by Cherry (black MX, yay).
> It's interesting that the keyboard decode routines in ROM actually support
> a
> few more keys than the actual keyboard has. As my old terminal keyboard had
> plenty of extra keys I've wired up those extra keys too. For example I'm
> able to switch between the two character sets in both directions e.t.c. .
> Maybe I should make a new PCB that fits in the CBM II keyboard case and use
> the switches from this terminal. However I'm not sure enough keys will fit,
> and it feels lika a really bad idea to cut out a bigger hole for the keys
> in
> the case. The CBM II machines are probably rather rare as I understand it.
>
> I currently only have a datasette as storage, but some kind of plan
> involves
> building some kind of IEEE 488 disk drive emulator, or maybe a general
> emulator of all kinds of C= IEEE hardware. (AFAIK there were disks,
> printers
> and a rare accoustic modem. With an emulation of a "modem" the PET could be
> used as a terminal for for example a Linux computer.
>
> I'm also known for making lots of plans and seldom actually go through and
> finish my projects.
>
> P.P.P.S.
> I got hold of some old electronic junk that contains a bunch of edge
> connectors that physically fits the PET but the connectors are "single
> sided" in the sense that it short circuits the upper and lower pins in each
> position, thus only usable for the datasette ports. The connectors are
> wider
> than the datasette port, and I haven't got any of those "key" things, so
> you
> have to cut the connectors and also make some kind of key to be sure it's
> not inserted incorrectly. Is there any interest for such connectors? The
> could probably be used with C2N232 with some effort, but otherwise they are
> probably rather useless.
>
>
>
> --
> View this message in context: http://cbm-hackers.2304266.n4.
> nabble.com/Commodore-8296GD-tp4655718p4662955.html
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>
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