PDA

View Full Version : IMSAI 8080 serial terminal



thefoolonthehill
December 17th, 2005, 11:10 AM
how would I be able to make a serial cord to plug into an IMSAI 8080 and then into the back of a PC and connect to it with HyperTerminal and use it as if it were a serial terminal? The ports on the back are not a normal Serial port and I have a serial card they're connected to. Also, does anybody have a bootstrap for an 8" diskette drive?

Erik
December 19th, 2005, 08:55 AM
What do you mean "not normal serial ports?"

Basic serial communications is accomplished with pins 2 and 3 (send and receive) on the serial port. These are the same for 25 pin and 9 pin varieties.

Depending on how your system is configured you may need a cable that connects pin 2 on one device to pin 3 on the other (Null Modem) or a straight serial cable (2-2, 3-3.) There are several other signals that may or may not make a difference to your configuration (RTS, CTS, CD, etc.)

Your best bet, for starters, is a simple cable connecting pins 2 and 3 to each other at both ends. If you aren't getting anything then switch the pins to null modem. A breakout box is VERY useful for sussing out serial communications. . .

Good luck!

Erik

thefoolonthehill
January 2nd, 2006, 03:25 AM
Well, see I meant by "not normal" is the ports on the back of the computer act like 9 pin serial ports, but look like regular old parralel printer ports. I found the pinout for it and I'm thinking about building an adapter to plug into a PC. Or I might break down and start looking for an ASR-33 (wish me luck) teletype, cause I'd also like a paper tape reader. But first I must concentrate on actually getting the system working.[/list]

NathanAllan
January 2nd, 2006, 04:00 AM
Here's a link for the rs232 serial port.

http://www.lammertbies.nl/comm/cable/RS-232.html

that oughta make it easier for you to make either a straight or null modem cable. You should be able to find the 25-9 adapter in any computer store worth their silicon (if it'll work on your terminal).

Now I wanna hook one up...

Terry Yager
January 2nd, 2006, 01:28 PM
Are the 25-pin connectors male or female? Parallel ports are usually 25-pin female, and the older serial ports used male connectors usually (on PC-compats, anyways). On a computer from before IBM "standardized" the connectors, it could be either M or F, or even both. My Kaypro 10 has one of each, one wired for DTE, and the other is DCE.
I have a few adaptors, null modems, loopbacks, breakout boxex, etc here. If you can figger out which one you need, I'll see if I have it.

--T

thefoolonthehill
January 2nd, 2006, 07:09 PM
I got it all figured out. I can buy an adapter online for like 5 bucks. No prob. Now I just need the working RAM board.