I think the Greg is right you have to open for input and output. I havent done bidirectional serial from basic. Just assembly.
Is flow control at play here? Remember the receive queue is 64 bytes. If responses are longer than that you're going to lose data unless flow control is engaged. -- John. On Mon, Oct 29, 2018, 8:27 AM Scott Lawrence <yor...@gmail.com> wrote: > Hi all. > > So I'm working on a project; a BASIC program that talks at 4800 baud to a > LaserDisc player. The commands are sent as ascii text, with a carriage > return at the end, and responses are similarly a text string terminating in > a CR. > > On my Tandy 200, I'm able to configure the port in TERM via: > STAT 78N1DNI > > And then i can type out commands and the player works and responds with > the correct responses... so I know the serial line is working in both > directions as designed. > > In BASIC, i know i need to open the connection for INPUT and OUTPUT so > that I can write stuff and read back the responses. The following code > works to send out the commands, but it gets errors no matter what I try for > reading in the response > > 10 OPEN "COM:78N1DNI" FOR OUTPUT AS 1 > 20 ON COM GOSUB 100 > 30 COM ON > 40 REM Send seek to frame 1000 > 50 PRINT #1, "FR1000SE" > 60 REM when the player gets there, it responds "R<CR>" via serial > 70 GOTO 70 > 100 REM Got serial response > 110 A$=INPUT #1 > 120 PRINT "Got ", A$ > 130 RETURN > > I looked around in a few online T books, but couldn't really find anything > that could help me out on this one, and I'm feeling pretty stupid that me, > a web applications and embedded systems engineer can't figure out a BASIC > program.... It's been YEARS since I messed around with BASIC, and even then > I never really did much with opening files... > > sidenote, "ON COM GOSUB <xxx>" ?!?! That's an awesome feature! I love > that we can have interrupt-driven serial in BASIC! > > Side-sidenote; I also don't really have a good solution yet for saving and > restoring the files but i'll probably just do serial port dumps or > somesuch. ;D I know i can buy NADS or REX or something, for file offloading > but this is a short-term project for Maker Faire next month, and I don't > have the cash to drop on fancy stuff right now. I'll probably just throw > together a serial-terminal based SD card shell using a spare arduino or > something... Although I'd gladly trade my Booster Pak which i never > really got working for one of those... ;D > > -s > > -- > Scott Lawrence > yor...@gmail.com >
