ASCI u68 (SystemX)

Often you have to press RETURN or SPACE a few times to wake up the serial connection and set the baud rate; if you put a scope on the RX and TX lines, do you see the incoming signal from the terminal and does anything get sent back? Can you trace the RX and TX signals to see what chips are used to convert RS-232 to TTL? m ----- Original Message ----- From: "Brad" <unclefalter at yahoo.ca> To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org> Sent: Friday, October 16, 2015 4:37 PM Subject: RE: ASCI u68 (SystemX) Thanks Henk, I tried that. No prompt comes up with PUTTY on serial set at any baud rate. Instead on the LED display I get a C, or an S sometimes. -----Original Message----- From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Henk Gooijen Sent: Friday, October 16, 2015 11:56 AM To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Subject: Re: ASCI u68 (SystemX) -----Oorspronkelijk bericht----- From: Brad Sent: Friday, October 16, 2015 8:27 PM To: 'General Discussion: On-Topic and Off-Topic Posts' Subject: RE: ASCI u68 (SystemX) Many thanks. I'll take a quick look online just to see if I can save you the trouble. I'm surprised at how little documentation there is for this thing. As a general rule, does anyone know -- if you have a single board computer like this with serial connector, is that 'live' all the time? Or do you usually have to invoke a program in order for a terminal to connect to it and use it? --------- port is always active. The on-board monitor with very basic commands uses it as only means of communication. After reset the monitor will "print" possible a one-line identification and on the next line some form of prompt. Could be * or . or > or - or whatever. You need to know the com ports settings, but it prints an ID line you can try several baudrates. 9600 is a good start. If you want 6800 info, ask. I can dream 6800 opcodes! INX=$08, LDA # =$86, DEX=$09, STAindexed =$A6. etc. Depending on the RAM size, I have a StarTrek version in 6800 assembler that uses a serial port ... IIRC, it is some 1.5k - Henk ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2015.0.6172 / Virus Database: 4447/10805 - Release Date: 10/12/15