Hello all.
I have owned my PCjr for years but never did anything with it.
Recently I have been playing with these old Micro controllers called Basic Stamp again. I had a lot of fun with them back in the 90s. The original software is DOS based but it needs 256K ram. I hope to be able to use my PCjr to program them with the jr-IDE I just ordered.
Getting to know my PCjr
Re: Getting to know my PCjr
The Jr should be fine for that - the serial port has some limitations but it generally works.
The machine uses the 8250 UART which only has a room for a single byte in the FIFO. This means the machine is going to be more likely to drop bytes when it gets busy, like using the floppy drive. The BIOS only supports up to 4800 BPS but it can be made to run at 9600 BPS if you program the divisor latches directly, and if the machine does absolutely nothing else. (Even touching the keyboard can cause bytes to be lost, as the main CPU has to decode the keyboard on a PCjr.) Technically you can't get the speed exactly at 9600 on a PCjr because of the clock crystals that were used, but it is "close" enough for serial.
The jrIDE will take care of the RAM problem and make the machine generally more enjoyable.
Oh, and welcome!
-Mike
The machine uses the 8250 UART which only has a room for a single byte in the FIFO. This means the machine is going to be more likely to drop bytes when it gets busy, like using the floppy drive. The BIOS only supports up to 4800 BPS but it can be made to run at 9600 BPS if you program the divisor latches directly, and if the machine does absolutely nothing else. (Even touching the keyboard can cause bytes to be lost, as the main CPU has to decode the keyboard on a PCjr.) Technically you can't get the speed exactly at 9600 on a PCjr because of the clock crystals that were used, but it is "close" enough for serial.
The jrIDE will take care of the RAM problem and make the machine generally more enjoyable.
Oh, and welcome!
-Mike
Re: Getting to know my PCjr
OK good to know about the baud limits.
The Stamp2 programs at 9600 baud so it will be interesting to see if that works.
The Stamp1 programs at much less and actually uses the parallel port. Serial data on pin 2 to the Stamp and Serial data on the "BUSY" line for input from the stamp.
The Stamp2 programs at 9600 baud so it will be interesting to see if that works.
The Stamp1 programs at much less and actually uses the parallel port. Serial data on pin 2 to the Stamp and Serial data on the "BUSY" line for input from the stamp.
Re: Getting to know my PCjr
Well I am happy to report that the Basic Stamp2 software does work fine with the JR-IDE and the PCjr built in RS232 
Its able to send a program and receive debug data back from the unit just fine.
Its able to send a program and receive debug data back from the unit just fine.
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