12 Dec
2008
12 Dec
'08
3:36 p.m.
What options are there for adding an RS-232 port to a Commodore PET? The computer's
user port has a different pinout from the C64 (although it uses the same connector), and
the port doesn't have the serial output signals the 64 does. Therefore, the quick and
dirty hacks that worked great on the 64 to provide serial won't work on the PET.
What communications options exist/existed for the PET, aside from Commodore-produced
IEEE-488 modems? Does the ROM include routines to handle such communication, like the C64,
or would software need to be created for a particular interface? Is there a teminal
emulation software available for the PET?
I have an 8032, and an 8050 disk drive - but of course, the 8050 is completely
incompatible with nearly everything else - serial communication would be a big help.
This is new territory for me - the C64, I know. The PET... I'm learning :)
-Ian
12 Dec
12 Dec
4:04 p.m.
there were some books around at the time, I had one interfacing to the
Commodore Pet if I remember the title correctly. I used a circuit from
there to put S100 bus in my Pet (which I still have) I will rummage
for the book over the weekend see if I can find it
Dave Caroline
archivist on irc
4:13 p.m.
On Fri, Dec 12, 2008 at 3:36 PM, Mr Ian Primus <ian_primus at yahoo.com> wrote:
What options are there for adding an RS-232 port to a
Commodore PET? The computer's user port has a different pinout from the C64 (although
it uses the same connector), and the port doesn't have the serial output signals the
64 does. Therefore, the quick and dirty hacks that worked great on the 64 to provide
serial won't work on the PET.
What communications options exist/existed for the PET, aside from Commodore-produced
IEEE-488 modems? Does the ROM include routines to handle such communication, like the C64,
or would software need to be created for a particular interface? Is there a teminal
emulation software available for the PET?
I have an 8032, and an 8050 disk drive - but of course, the 8050 is completely
incompatible with nearly everything else - serial communication would be a big help.
This is new territory for me - the C64, I know. The PET... I'm learning :)
-Ian
The SuperPET is basically a 8032 with additional board containing a
6809, RAM and a 6551. ISTR it was mapped somewhere around $E000.
However, I don't know if it ever saw widespread use other than from
the 6809 side (where I think the Waterloo software wanted it to talk
to a `real' computer).
Still, I think it would be an (historically) appropriate expansion to
a stock 8032. You should have a big two-row header on the right side
of the PET motherboard where you could add such a project.
I do have a Commodore IEEE-488 acoustic coupler hanging about, but I
don't have the power supply and have never used it.
Long ago, I did hook a modem up to my SuperPET using the (internal)
DB-25 connector, and even looked into writing a terminal emulator -
but I was otherwise busy at the time and abandoned that project.
Joe.
PS. Ian, there are still the Apple II's for you to pick up, you can
have a look at the PET stuff as well when you're here (but I'm keeping
it!) - unfortunately, the weather has gotten somewhat messy :-)
--
Joachim Thiemann :: http://www.tsp.ece.mcgill.ca/~jthiem
4:24 p.m.
Mr Ian Primus wrote:
What options are there for adding an RS-232 port to a
Commodore PET? The computer's user port has a different pinout from the C64 (although
it uses the same connector), and the port doesn't have the serial output signals the
64 does. Therefore, the quick and dirty hacks that worked great on the 64 to provide
serial won't work on the PET.
What communications options exist/existed for the PET, aside from Commodore-produced
IEEE-488 modems? Does the ROM include routines to handle such communication, like the C64,
or would software need to be created for a particular interface? Is there a teminal
emulation software available for the PET?
I have an 8032, and an 8050 disk drive - but of course, the 8050 is completely
incompatible with nearly everything else - serial communication would be a big help.
BTW, you do know that the 8050 has an IEEE-488 interface and not a
serial interface, right?
Cheers,
Bryan
P.S. The 8050 is compatible with a C64 and the proper interface
cartridge.. ;-)
This is new territory for me - the C64, I know. The
PET... I'm learning :)
-Ian
4:31 p.m.
--- On Fri, 12/12/08, Bryan Pope <bryan.pope at comcast.net> wrote:
BTW, you do know that the 8050 has an IEEE-488 interface
and not a
serial interface, right?
Of course. I had to make the bloody cable myself... <grin>
By "serial communication", I was referring to the possiblity of transferring
data over an RS-232 link, not through IEC serial, like on the 64.
-Ian
I have an
8032, and an 8050 disk drive - but of
course, the 8050 is completely incompatible
with nearly
everything else - serial communication would be a big help.
4:39 p.m.
should be a way/was a way to use the 6522 VIA chip it will need
translation to rs232 levels though
Dave Caroline
9:22 p.m.
On Fri, 12 Dec 2008, Dave Caroline wrote:
should be a way/was a way to use the 6522 VIA chip it
will need
translation to rs232 levels though
Does anybody here remember a thread from last month called:
Re: RS232 voltage level converter box
(trying to figure out what a board with 1488s and 1489s was for)
15 Dec
15 Dec
10:22 a.m.
Fred Cisin wrote:
On Fri, 12 Dec 2008, Dave Caroline wrote:
Yep. That was my thread. And the box is still sitting here looking at
me. :-)
(I've not had a lot of time to play lately ...)
Mike
should be a way/was a way to use the 6522 VIA
chip it will need
translation to rs232 levels though
Does anybody here remember a thread from last month called:
Re: RS232 voltage level converter box
(trying to figure out what a board with 1488s and 1489s was for)
12 Dec
12 Dec
4:30 p.m.
What options are there for adding an RS-232 port to a Commodore PET?
The way I've always seen it done [1] was to have an IEEE-488 to RS232
interface. The ones I have were made by -- Oh, I forget, something like
'Small Systems Inc' (Philip, do you rememebr), I have the B200
(EPROM-based stat machines + UART) and B300 (8048-based). I am sure thre
were others, anyway, making an IEEE-488-RS232 interface is a good
exercise in understand the IEEE488 bus (if you want to do that :-)).
[1] Years ago I was given an HP plotter with an IEEE-488 interface. At
the time, the computer I did most of my work on was a CoCo. I remember
using a PET + 8050 disk drive + B200 RS232 interface to simply read bytes
coming on the RS232 line from the CoCo and send them to the plotter.
Overkill, but it worked.
That method has the advantage of needing minimal software -- the standard
BASIC I/O commands will work. But I can think of 2 other solutions that
might work, if you don't mind writing the software.
1) Bit-bang it on 2 lines of the user port. Easy for output, a lot harder
for input if you want to avoid dropping characters -- you have to keep on
polling that RxD line :-). Then buffer those lines to RS232 levels using
a MAX232 or similar.
2) Hang a seiral chip off the system bus, mapping it to some unused
address. Obvious choices for the seiral chip (as they'll interface to the
6502 bus easily) would be the 6850 (needs an external baud rate
generator) or the 6551 (internal baud rate generator). Again you'd have
to buffer the serial lines to RS232 levels. You'd have to write driver
code for the chip you use, but it's a lot easier than writing the
bit-banging program.
-tony
7:05 p.m.
On 12/12/08, Mr Ian Primus <ian_primus at yahoo.com> wrote:
What options are there for adding an RS-232 port to a
Commodore PET?
There are a couple that I am aware of...
The computer's user port has a different pinout
from the C64 (although it uses the same connector), and the port doesn't have the
serial output signals the 64 does. Therefore, the quick and dirty hacks that worked great
on the 64 to provide serial won't work on the PET.
As far as I recall, there's nothing magical about the "serial" pins on
the C-64 except that there's some ROM routines backing them up so that
you just "OPEN 2,2" and it's all "handled". I _think_ someone
did
port those routines to the PET, but I couldn't tell you what magazine
it was published in.
What communications options exist/existed for the
PET, aside from Commodore-produced IEEE-488 modems?
I have a TNW (The Net Works?) IEEE-488 serial adapter. It's a "dumb"
UART like a 6402 that you strap for baud, stop bits, parity, etc., and
enough logic to gate its 8-bit RCV and 8-bit TX buses onto and off of
the PET's IEEE bus. Since there's no CPU, it's more than a small
handful of popcorn logic. It could probably be done these days with a
small amount of bus drivers and GALs/CPLDs in a fraction of the space.
I also have a ROM-socket 6850 adapter. It occupies the entire ROM
space (i.e., it doesn't share the socket with a ROM), but it's easy to
address from software on the PET side. You have to write your own
software from scratch, but it's less tough than bit-banging, I'd say.
The circuit is trivial since ROM sockets have the data bus, plenty of
address bits and address enables. The only thing you need is a flying
lead for R/W (since ROM sockets do _not_ have that).
Does the ROM include routines to handle such
communication, like the C64, or would software need to be created for a particular
interface?
The PET has no facilities specifically for serial port comms, unlike
the C-64. Something like the TNW adapter would be easy to talk to -
regular PET I/O (OPEN, PRINT, INPUT, GET). Wiring up a 6850 or using
User Port bit-banging would require custom software.
Is there a teminal emulation software available for
the PET?
I think I've seen something in BASIC for the IEEE acoustic coupler (it
would resemble the example one given in the VIC-MODEM manual), but I
don't recall any comms software specifically for the PET back in the
day.
-ethan
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10 comments
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participants (9)
-
ard＠p850ug1.demon.co.uk -
bryan.pope＠comcast.net -
cclist＠sydex.com -
cisin＠xenosoft.com -
dave.thearchivist＠gmail.com -
ethan.dicks＠gmail.com -
ian_primus＠yahoo.com -
joachim.thiemann＠gmail.com -
mbbrutman-cctalk＠brutman.com