My main argument with this book is that the title is insufficiently descriptive. The author certainly does cover the general problem of an RS232 class but his entire viewpoint is coloured by the need to support 8250 compatible UARTs.
Serial communications has several problems.
The first is one of speed. The time overhead that is paid for using a high level language is generally one that cannot be afforded. I believe that good assembler level drivers are needed which can be managed via C functions. I am rather luke-warm about this book. I almost abandoned reviewing it and put it on the list for someone else.