Harold,
I got burned (both litterally and figuratively) by some MAX232 chips I bought from China. Same deal, they got hot and stopped working. Throw them out! Cheers, Josh Date: Fri, 18 Sep 2015 17:34:36 -0700 From: hlrj...@gmail.com To: n8vem...@googlegroups.com Subject: [N8VEM-S100:7593] Re: setup for the serial I/O board? My system consists of the Z80 board version 2 with the latest monitor program (version 5.02?). I have the 4Meg RAM board and the dual IDE CF board. I am using the Propeller I/O for the console. The operating system is CPM3 banked. I am using all boards that you designed? I am also using an active terminated bus.
Part of my problem with the serial I/O board is the MAX232 chips. I am using the MAX232N with 1uF electrolytic caps. I bought 4 chips and 2 of them were dead! The other two seem to be heating up over time. When I first turn on the computer the serial board works fine, but after about 15 minutes I can't get reliable transmission. I have used the max232 chip once before on a heathkit project and as I remember I had some problems also. Do you have any advice? Also I plan to use the serial board with xmodem to transfer programs between the Z80 and my PC. Your monitor program does not have an option to change the serial baud rate. The only way to change the baud rate is to run MYIO from CP/M. When I run MYIO and change the baud rate I don't know how to exit CP/M and get back to your monitor program without a reset which causes the serial board to reinitialize to 38400. I guess I don't understand some of the options. Thanks for the help Harold On Tuesday, September 15, 2015 at 6:04:15 PM UTC-4, hlr...@gmail.com wrote:
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