On Tue, Jan 28, 2003 at 10:48:01PM +0000, Hugh Saunders wrote: > On Tue, Jan 28, 2003 at 09:05:18PM +0100, Frank Gevaerts wrote: > > On Tue, Jan 28, 2003 at 06:12:10PM +0000, Hugh Saunders wrote: > > > Hello, i am attempting to build a serial cable so i can use an old mac > > > laptop [powerbook510] to boot a sun sparc ipc and start it network booting. > > > Google reveals the following pinouts: > > > > > > AppleMac [1] > > > DIN8 Signal Description > > > Pin > > > ---------------------------------- > > > 1 RTS Handshake output > > > 2 CTS Handshake input > > > 3 TXD- Transmit data (inverted) > > > 4 SG GND > > > 5 RXD- Receive data (inverted) > > > 6 TXD+ Transmit data > > > 7 DCD General Purpose Input > > > 8 RXD+ Receive data > > > > > > Sparc IPC [2] > > > DIN8 Signal Description > > > Pin > > > ---------------------------------- > > > 1 DTR Data Terminal Ready > > > 2 CTS Clear to Send > > > 3 TXD Transmit Data > > > 4 GND Ground > > > 5 RXD Receive Data > > > 6 RTS Request to Send > > > 7 DCD Data Carrier Detect > > > 8 RTXC Receive Clock > > > > > > My first question is: how do i wire it? do i try and match the pins up ie > > > RTS-->RTS or do i cross over as in RTS-->CTS? > > > > > > Next question, whats with TXD[+-] on the mac but only TXD on the sparc? can > > > i just use TXD+ -->TXD? [or TXD+ -->RXD if crossed over] then ignore > > > TXD-? > > > > I would wire TX+->RX, RX+->TX, and GND->GND, and leave the rest > > unconnected at first, and if you really need hardware handshaking, > > RTS<->CTS and CTS<->RTS. > Thanks, i understand up to here... > > > IIRC some systems also need DTR and /or DCD to > > be wired high > wired high?
connected to the voltage that represents a logical 1 on the interface concerned. > will try with just the three you suggest for now... Watch out! Check the specs first. IIRC a Mac uses an RS-422 interface with 5V levels, whereas RS-232 uses 12V levels. Sometimes an RS-232 input will work OK when fed 5V signals, but going the other way, there's a risk of overloading the RS-422 input. You need a level converter, which is dead easy to make, but perhaps you're not comfortable with doing stuff like that... I'd be really surprised if you couldn't buy them, so have a look on Google for something like rs232 rs422 "level converter". Pigeon -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
