and Pin No.
|Data in V24||RS232 in (2)||2|
|Data out V24||RS232 out (14)||3|
|Request to send (RTS)||Generated by terminal||4|
|Clear to send (CTS)||–||5|
|Data set Ready (DSR)||–||6|
|0v (Ground)||RS232 Com (8)||7|
|20mA input -ve||KBD – (4)||10|
|20mA output +ve||PTR + (12)||16|
|20mA output -ve||PTR – (11)||17|
|Reader step -ve||–||18|
|Reader step +ve||–||19|
|Data Terminal Ready (DTR)||Generated by terminal||20|
|20mA Input +ve||KBD + (5)||24|
We have included a number of signals which are not generated by the Nascom-1
for your information and to aid standardisation. You can interface a relay
to the PIO to provide reader step if required.
Because the Nascom keyboard users non-standard values for newline (1FH), you
will need to patch $KBD (0C4DH) and $CRT (0C4AH) to generate carriage returns
and line feed (0DH and 0AH) in place of newline on output, and replace them
with newline on input. Don’t forget that you may also need to ignore parity
on input and generate it on output, depending on the terminal you are using.
You may like to take special action on receipt of a backspace (Nascom 1DH to
ASC11 08H) or formfeed (Nascom 1EH to ASC11 0CH). (See also the software
listing for a printer driver).
As most of you probably know by now, the original version of Nasbug had an
error which resulted in a high error rate when loading cassette tapes. A
patch to correct this was sent to all INMC members sometime ago. However, a
number of people appear not to have received this so we are re-publishing it
as part of this newsletter (see below).
Nasbug version T2 has been modified to incorporate this patch and all kits
sent out since early July already have this modification included. If you
have an old version of Nasbug, you can send it back to us, enclosing £1.00
and we will reprogram it for you to bring it up to the T2 standard.