Viking SCSI controller RS232 adapter

[Daniel Seagraves]

> On Jun 28, 2022, at 1:29 PM, Douglas Taylor via cctalk <cctalk at classiccmp.org> wrote:
> 
> On 6/28/2022 12:58 PM, Douglas Taylor via cctalk wrote:
>> I have a couple of these boards but have never got into the on-board monitor which requires an adapter board that allows a terminal to talk to the controller board and do various things.
>> 
>> Looking at the manual on bitsavers there is almost enough info to construct my own adapter board.  Has anyone ever built there own adapter to the controller?
>> 
>> Doug
>> 
> I wasn't clear about this.  The Viking board I have is a dual width q-bus board that connects SCSI  disk or tape devices VAXes or PDP11s using MSCP protocol.   In the bitsavers manual on figure 8 is a drawing of the 'Serial Port Cable Adapter'.  Table 2 lists the pin-out of the 50 pin IDC connector and which lines are used for what signal.  In that list are these RS232 connections:
> 
> IDC pin 20 -> CON TX (RS232)
> 
> IDC pin 22 -> CON Rx (RS232)
> 
> IDC pin 28 -> FP TX (RS232)
> 
> IDC pin 30 -> FP TX (RS232)
> 
> I was able to trace these IDC connections back to an ICL232 chip on the Viking board which is an RS232 driver chip.
> 
> My question is which of these RS232 lines are brought out to the 'Serial Port Cable Adapter'?  Which ground do I use?  What do CON and FP stand for?
> 
> I am trying to de-bug one of the boards and would like to get into the on-board monitor and see what it tells me about the board configuration.

For the UDT at least the RS232 lines are regular RS232 and the plug I made for communicating with it was just an old PC serial pigtail bodged onto a short SCSI ribbon cable.

I would expect CON to be CONfiguration port; No idea what FP is for.