Batch File Command Parameters

This is pretty much a shot in the dark, but instead of -Bn = 2, I assume you're doing this to get 1200 baud?, it should be -B2. I don't have a clue what the rest of the statement, '1.f 1.wav', is doing.

Are you using BASICODE?

http://www.iol.ie/~geniet/eng/BASICODE2sub.htm

No, it is just standard parameters. I changed the standard to CUTS format which is 1200 baud. I am now getting about 500kb on a standard tape. I just record it to tape at an 88200 Hz sample rate when the wav files that it produces are 22050. If I record the tape into the computer to a wav file, I record it at 88200 and change it back to 22050 to keep the baud rates matching. To write a 97kb bitmap image to the tape, it takes 3 minutes and 45 seconds at 4800 baud. This is on my modified high speed tape drive.

Another blind guess

if you're under Windows you likely can't change/initialize your COM from command line
you have to set it manually from

My Computer/Properties/Hardware/Device/Manager/Ports/Serial Port (COM?)/Properties/Port Settings

...

another issue is with the RS-232 Cable itself - i've managed top Baud X-on/X-off /!\ with Windows [ Hyper Terminal <~~> Hyper Terminal ]

but there was a percent of error packets

when transmitting (digital as) analog - the error (flow) control is an unknown beast

you likely shoud consider adding a module to your tape drive (PIC based or something - that generates signals locally _ _ _ your data needs to be there ontime (buffer MEM) _ nothing's easy & you do have to reinvent the bike most each time again and again (coz the suystems are unique))

I have actually found that the CUTS standard is far more stable than KCS. I think I may now be able to get 2Mb on each tape now because I can record different files to each audio channel and turn over the tape and do likewise. The data rate is just under 1Kb/s. I recorded several bitmap images to tape and read them back and there was not one error on the whole tape.