H89 as serial terminal

Hey guys, thanks for all the info. I would prefer to go the software route (I'd prefer to run CPM and find a C compiler...) but I'm having a hell of a time tracking down disks for this thing so in the meantime I'm looking for a hardware hack to make it useful (or at least make it do something to freak out my fellow employees as my syslogs scroll across the screen of this beast), so the hardware solution is what I was looking for (I could have been more specific). On that note, if any of you know where I could find a copy of CPM and a compatible C compiler on hard-sectored disks, that would be greeeaaat, yeah. Thanks again! -----Original Message----- From: cctech-admin(a)classiccmp.org [mailto:cctech-admin@classiccmp.org] On Behalf Of Patrick Rigney Sent: Friday, March 28, 2003 1:02 AM To: cctalk(a)classiccmp.org Subject: RE: H89 as serial terminal Dwight, you're absolutly right, the software is not always "easy" to find and get. Actually, check that... it's really easy to find and get (Google), it's just not as easy to get onto a Heath-format floppy so you can use it. On the other hand, I think the software approach has its merits, especially over the long haul. Using a terminal emulator is a more permanent solution (IMHO) than cracking the case and swapping connectors around to reconfigure the device as a terminal or computer. And, the terminal logic board communicates with the CPU board at 9600 baud, so if you want a different rate for the device you are talking to, the board has to be pulled and jumpers/switches changed, and then pulled and changed back if you want to use it as a computer again. The three-port serial card has software configurable baud rates. The hardware approach will also not make it emulate VT-100, which is part of what Jason had asked. And since many of these programs can X/Y/Zmodem, getting other stuff onto the machine from there forward gets a lot simpler. While you, I, and others may feel quite comfortable mucking around with the innards of the beast, perhaps (and I don't know one way or another for sure) Jason or anyone else who might later read this thread in archives or digests may be less comfortable or is just working up to it, and so other alternatives are worth mentioning (IMHO). Tony's hardware solution is good, but rerouting even one of those cables may require removal of the CPU and terminal logic boards, since the interconnect and serial cables are typically routed around the bottom edge of the two boards and fairly tight once home. If you're going to go back and forth between terminal and computer, maybe that's a bit much in the long run. Add to this that the expansion boards and some of the other connectors attached the CPU board are all unkeyed and thus notoriously easy to (re)install one pin off their mating connectors, and this little accident can cause the kind of rapid deep frying on the CPU board that will turn a wonderful H89 into a dumb terminal permanently. I'm into risk management and choices. That's all. I certainly didn't intend any offense with my comment. But since we're into options... to elaborate on your and Tony's path, the terminal logic board's serial port is easily accessed from the rear of the machine--remove the lid, and as you face the back of the machine, it's on your left (you can sometimes read "P404" next to it). If a cable is the solution of choice, then Molex directly to a DB-9 or DB-25 (whatever the device to be connected requires) is the way to go, IMHO. That way, you can just open the case, pull the interconnect, connect in its place this new cable to the target device, and do your thing. Reverse to undo, lather-rinse-repeat as needed. That won't get you VT-100, software transfer, or other baud rates, but it is quick and dirty. To that end, P404 on the terminal logic board is a 15-pin connector with 10 pins connected. For those interested, the pinouts are (from schematic w/no revision number evident, identified Heath p/n 595-2268/595-2272): 1 - (black) ground 2 - no connection 3 - (brown) TxD 4 - n/c 5 - (red) RxD 6 - n/c 7 - (orange) RTS 8 - n/c 9 - (yellow) CTS 10 - n/c 11 - (green) DSR 12 - n/c 13 - (blue) ground 14 - (violet) DTR 15 - (grey) "RLSD/" (whazzat? anybody?) The black wire (pin 1) is up in this vertical connector. Patrick