Compensate for timing
The KIM-1 character routines are quite primitive and not rebust : bit-banged, not interrupt driven, no hardware handshake so no buffering and it is CPU intensive.
When you sent characters quite fast to the KIM-1 (and that means any baud rate from 1200 to 9600, and the KIM-1 also has to do some processing like storing the record just received, it is to be expected the KIM-1 will be too late reading the next record, skip a record and sync at the next and leave the program received in chaos.
So we need to give time to the poor KIM-1.

1200 baud, 20 ms character delay, 200 ms line delay is conservative but reliable for me. It is slow ..

An example for Teraterm is shown here:

KIM usernotes vol 06

Jim McClanahan

Serial Interface
The connector that came with mine is a male DB-9. Most USB serial interfaces (or interfaces on older computers) are also male DB-9 wired as the DTE device. The PAL-1 has the pinout of a DCE, which would normally have a female DB-9 connector. To get things connected, I used a “gender changer” (DB-9 female-to-female with pins 2, 3, and 5 connected straigt through).

The PAL-1 (just like the KIM-1) uses a ‘soft UART’ or ‘bit banger’ for its serial I/O. I’m not a fan of this approach, but at the same time it demonstrates what could be accomplished with a minimial amount of hardware. The PAL-1 automatically figures out the appropriate delay between bits of the serial character when you press enter after a reboot. I have found that decreasing the value actually significantly improves the odds of an error-free load of larger punchtape format files. Below is a table for values found and suggest for $17F2.

Baud Found New
300 $EA $E8
1,200 $37 $35
2,400 $1A $18
4,800 $0B $0A

I haven’t tried to optimize the delay values. Right now I’m using 5 ms between characters and 500 ms between lines when doing 8K transfers and with the modified values I usually am successful. With the default values, it seemed like even with longer delays things would slip out of synchronization at some point more often than not on large transfers.