I would really like to tether my C64 to my Mac and have a bit of fun.If anone has any references or experiences I would be glad to hear from you.
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From: fr94tmg@ing.umu.se (Tomas Moberg) in Sweden:
I used to hook up a HP48 to a MAC and I only remember that the MAC doesn't use rs232. But one could turn the MAC signal easily into a rs232 some how (sorry was a long time ago and I dont remember how , You only shorted some pins or so). But first You would need a rs232 interface for Your c64 and a terminal program.
have not made this post ,I just found it on comp.sys.hp48 and modified it a bit.
Many people routinely ask for a pinout diagram for the mini DIN-8 connector; Figure 1.2.3 shows the pinout as if you were looking at the (female) connector on your Macintosh; the (male) cable connector will be a mirror image. (Figure artwork by Ben Cranston)
Mini DIN-8 Macintosh Serial Connector Pinout
/------###------\ 1 HSKo Output Handshake
/ ### \ (Zilog 8530 DTR pin)
/ \ 2 HSKi/CLK Input Handshake *OR*
/ [{CBM--}] [{CBM--}] [{CBM--}] \ External Clock
/ 8 7 6 \ 3 TxD- Transmit data (-)
{CBM--} {CBM--}
{CBM--} {CBM--} 4 Ground Signal ground
{CBM--} === === === {CBM--}
{CBM--} 5 4 3 {CBM--} 5 RxD- Receive data (-)
{CBM--} {CBM--}
{CBM--} {CBM--} 6 TxD+ Transmit data (+)
\----+ === === +----/
\###{CBM--} 2 1 {CBM--}###/ 7 N/C (no connection)
\##{CBM--} {CBM--}##/
\{CBM--} {CBM--}/ 8 RxD+ Receive data (+)
\------###------/
###
Figure 1.2.3
Note that the mac interface is RS422, which has 2 wires for transmit and 2 for receive, whereas the 48 interface has only 1 wire for each. Do the connections like this:
Mac: HP48:(c64)
TxD- ----------------- RX
RxD+ ---+------------- GND
{CBM--}
GND ---+
RxD- ----------------- TX
Shield ----------------- Shield
All other mac pins don't need to be connected. Then configure your communication software on the mac to use XON/XOFF flow control.
Good luck!
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From: Doug Cotton <cmd-doug@genie.geis.com>
Organization: Creative Micro Designs, Inc.
I transfer between Mac & Commodore 8-bit all the time, since we use Macs to produce Commodore World. I use a standard Mac high-speed modem cable attached to a DB-9/DB-25 Null-modem cable which is in turn attached to a SwiftLink. I do most of the transfers using Zterm on the Mac and Dialogue 128 on the Commodore, but that's mostly user preference... most any term program will do. By using SL and having the high-speed modem cable on the Mac, transfer rates of up to 38,400 bps can be handled using hardware handshaking (RTS/CTS).
I've also written a BASIC program in "Chipmunk BASIC" on the Mac to convert Commodore BASIC programs to text.
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From: c8923075@cs.newcastle.edu.au (Chris Baird) In: Australia
I was tiding up my Usenet archives from several years ago and discovered these instructions (of mine) for a simple 3-wire serial cable connecting a '64 to a Macintosh. I'll hazard someone else out there could find them useful too.
(And the original cable I made is still working flawlessly today--sans the occasional wire breaking off at the pin...)
[Quite a few years ago] I asked for info on connecting my 64 to a Mac Plus via a null-modem cable. Thanks to a few people (mostly Steve Coan), I'd managed to get a RS232 converter built and working, and had a few successful transfers before the bloody thing fell to bits on me.
The main problem with RS-232 on the 64, is that it doesn't comply with the RS232 standard (ie: instead of a -ve voltage level for "1", the 64 expects a TTL +5V), so you're required to have an inverter for the signals.
But...
The serial port on the Macintosh is actually a RS-422, and the hardware it uses for that is a differential amplifier, and so having two lines for each data line (an inverting & non-inverting input to the op-amp). To emulate the RS-232, the 422 port has the received data fed into the RxD- pin, and the RxD+ line grounded; the op-amp them producing a TTL "1" from a -ve signal. Also, the transmitted data is taken from the TxD- pin.
As anyone who has studied op-amps will tell you, inverting things generally involves swapping the inverting and non-inverting inputs.
[lets cut to the chase --cjb1994]
I've successfully used the following cable to connect the two machines via a 3-line interface:
[The pin numbers are for the "mini-din-8" connector of a MacPlus. For earlier Macs with the DB9 connectors, just use the corresponding pins (whatever they are, I've forgotten).]
You'll need: 1) 24 way edge connector suitable for the User port
2) Plug suitable for the RS-422 port
3) 3-core (at least) wire
4) Heatshrink tubing preferred but not essential
[5) A wiring diagram for the 64's User port)]
Wiring:
GND to pin 4: Ground
CB2 to pin 8: RxD+
CB1 & PB0 shorted together and connected to pin 6: TxD+
PB1 & PB2 shorted together
It may be best to ground the RxD- line, but I didn't see it as necessary for just a simple link between two machines.
