The Sinclair QL Forum

Much appreciated Jan. It's all Chinese to me but I think I have followed your instructions.

I now have the following:

PC pins 1 (DCD) and 6 (DSR) and QL Printer plug pin 9 are connected to the +12v from the other PC COM port (in my PC manual it states that only COM 2,3,4 are powered and at COM1 there was no +12v)
PC pin 2 (RXD) is connected to QL printer plug pin 3 (RXD)
PC pin 3 (TXD) is connected to QL printer plug pin 2 (TXD)
PC pin 4 is not connected to anything
PC pin 5 (GND) is connected to QL printer plug pin 1 (GND)
PC pin 6 (+12v as pin 1 above)
PC pin 7 (RTS) is connected to QL printer plug pin 4 (DTR)
PC pin 8 (CTS) is connected to QL printer plug pin 5 (CTS)
PC pin 9 is not connected to anything

I made sure the baud was set to 9600 (same as printer), OPENed #3 to ser then attempted to print with the printer set to On-Line, but nothing was printed.

Hi Chris,

Chr$ wrote:Much appreciated Jan. It's all Chinese to me but I think I have followed your instructions.

I now have the following:

PC pins 1 (DCD) and 6 (DSR) and QL Printer plug pin 9 are connected to the +12v from the other PC COM port (in my PC manual it states that only COM 2,3,4 are powered and at COM1 there was no +12v)

You only need to connect pin 1 and 6 to pin 9 of the QL Printer. Pin 9 is a +12V output on the printer and functions as DSR signal.

Jan.

janbredenbeek wrote:Hi Chris,

Chr$ wrote:Much appreciated Jan. It's all Chinese to me but I think I have followed your instructions.

I now have the following:

PC pins 1 (DCD) and 6 (DSR) and QL Printer plug pin 9 are connected to the +12v from the other PC COM port (in my PC manual it states that only COM 2,3,4 are powered and at COM1 there was no +12v)

You only need to connect pin 1 and 6 to pin 9 of the QL Printer. Pin 9 is a +12V output on the printer and functions as DSR signal.

Jan.

But that pin on the original QL side at idle measured +12v.

I removed the +12v from the PC from PC pins 1 and 6 and now have:

PC pin 1 (DCD) is connected to QL printer plug pin 9
PC pin 2 (RXD) is connected to QL printer plug pin 3 (RXD)
PC pin 3 (TXD) is connected to QL printer plug pin 2 (TXD)
PC pin 4 n/c
PC pin 5 (GND) is connected to QL printer plug pin 1 (GND)
PC pin 6 (DSR) is connected to QL printer plug pin 9
PC pin 7 (RTS) is connected to QL printer plug pin 4 (DTR)
PC pin 8 (CTS) is connected to QL printer plug pin 5 (CTS)
PC pin 9 n/c

Still nothing

I verified that the printer still works using the original QL just now.

Chr$ wrote:I removed the +12v from the PC from PC pins 1 and 6 and now have:

PC pin 1 (DCD) is connected to QL printer plug pin 9
PC pin 2 (RXD) is connected to QL printer plug pin 3 (RXD)
PC pin 3 (TXD) is connected to QL printer plug pin 2 (TXD)
PC pin 4 n/c
PC pin 5 (GND) is connected to QL printer plug pin 1 (GND)
PC pin 6 (DSR) is connected to QL printer plug pin 9
PC pin 7 (RTS) is connected to QL printer plug pin 4 (DTR)
PC pin 8 (CTS) is connected to QL printer plug pin 5 (CTS)
PC pin 9 n/c

Still nothing

I verified that the printer still works using the original QL just now.

When you have OPENed a channel to the ser port, check pins 4 and 7 on the PC port. They should both measure about +12V to indicate the port is ready. Also, CTS should be +12V, else the PC will wait forever for the printer. If pin 7 (RTS) doesn't go to +12V but pin 4 (DTR) does, then use pin 4. (I don't have a QXL to test this unfortunately).

Jan.

janbredenbeek wrote: When you have OPENed a channel to the ser port, check pins 4 and 7 on the PC port. They should both measure about +12V to indicate the port is ready. Also, CTS should be +12V, else the PC will wait forever for the printer. If pin 7 (RTS) doesn't go to +12V but pin 4 (DTR) does, then use pin 4. (I don't have a QXL to test this unfortunately).

Jan.

Both 4 and 7 change from -12v to +12v when I open the ser. Pin 8 (CTS) doesn't change though (stays at about 0v).

Chr$ wrote:

janbredenbeek wrote: When you have OPENed a channel to the ser port, check pins 4 and 7 on the PC port. They should both measure about +12V to indicate the port is ready. Also, CTS should be +12V, else the PC will wait forever for the printer. If pin 7 (RTS) doesn't go to +12V but pin 4 (DTR) does, then use pin 4. (I don't have a QXL to test this unfortunately).

Both 4 and 7 change from -12v to +12v when I open the ser. Pin 8 (CTS) doesn't change though (stays at about 0v).

Interesting, you mentioned earlier that CTS on the printer had -11V when not connected. How come it has 0v now?

Jan.

No, sorry for misunderstanding.

I said..... PC pin 8 (CTS, 0v idle....(and the new info is that when 'Open' it's also 0v)).

And that the pin 5 on the QL (CTS) had -12v at idle (or rather -11v, but close enough).

These were the BBQL pins:

(Only pins 1 - 5 and pin 9 are connected within the printer plug). I checked the voltages on those pins at idle and got the following:

1 - 0v (def ground)
2 - nothing much detected
3 - minus 11v
4 - nothing much detected
5 - minus 11v
9 - plus 12v

When I said QL printer plug pins I really meant the pins on the BBQL!

And thankyou again for your immense patience with me and this whole thing! Do you have a Q68? It looks like that has PC serial pinout and once I got this going with the QXL I was hoping to use the same adapter to print from the Q68.

Chr$ wrote:No, sorry for misunderstanding.
When I said QL printer plug pins I really meant the pins on the BBQL!

Just to be sure... are you trying to connect your PC running QXL to the QL Printer or to your BBQL?

And thankyou again for your immense patience with me and this whole thing! Do you have a Q68? It looks like that has PC serial pinout and once I got this going with the QXL I was hoping to use the same adapter to print from the Q68.

The Q68 indeed has the same pin layout as a 9-pin PC serial port, but unfortunately the flow control lines such as DTR and CTS are missing. This probably won't work out well with a serial printer as this needs flow control, else it cannot handle the stream of data coming from the Q68.

Jan

janbredenbeek wrote: Just to be sure... are you trying to connect your PC running QXL to the QL Printer or to your BBQL?

Yes, that's what I'm trying to do. My QL printer has a connector that fits the German SER1 and works perfectly on the German BBQL.