> I have a CPU Controller card (8085 based, vintage �1987). The motor blew on > the machine, power surges came and went, and now it won't communicate > with the outside world. One chip is totally (I mean tetotally) > destroyed, right beside the serial port. The com port on the relevant pc > has also been blown, beacuse it was connected at the time. > > What was it? I know it's Texas Instruments, silver topped (SN something) > and 14 pin. It's partner in the RS232 circuit is a 75152 (a Line > Driver). On this mystery chip, pin 7 is 5V ground, Pins 4, 9, 12 are to > the 5V circuit. Pin 4 was really blown off the chip, and there sure was > some heat around. Miraculously, the machine (A huge Turret Punch) > > Has anyone a memory long enough to remember how these circuits were > configured? I am used to MAX 232s with electrolytics around; this board > has no capacitors in sight. No power supply onboard. How did they do > RS232 back in those days?
MC1488 and MC1489 were the most common, TI versions were 75188/189. The driver required +/- 12 VDC in addition to +5. -- Author: Dave Baldwin INET: [EMAIL PROTECTED] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
