Hi Larry. I'd love to have a look at your code. As a side note, have you considered posting it at http://www.piclist.com ? That way everyone can access it without you having to email it out. Just a thought, Josh -- A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. -Douglas Adams Larry Kayser wrote: > > Greetings: > > I have for some days been struggling with achieving consistent and accurate > serial port operation, especially when the Interrupts are being hit at a > high rate. The APNOTE from MICROCHIP does not work most of the time and > never worked properly. However a fine piece of work by Tom McGahee, > PICUART.ASM for the 16C74A should be adaptable to the 16F628. > > It was adaptable and works like a charm. I have now tried this with the > following Oscillator configurations. For the 16F628, the Internal 4 MHz, > an external 4 MHz crystal, a 1.8432 MHz crystal and with a high speed > 16F628 it ran just fine with a 21.7 MHz crystal. > > I will send any and all who ask a copy of this ASM file, which I happen to > call PIC8_4B.ASM, configured to run on a 4 MHz crystal or 4 MHz internal > oscillator by just compiling it with MPASM. > > I will decline to express my thoughts about Microchip documentation and > product support. It is suffice to say that my first copy of CPM-80, the > one with both handwritten and typewritten documentation from Gary Kendall > about 1976/7 was of higher quality and vastly more accurate than what I > have received from Microchip for the 16F628. > > Larry Kayser > VA3LK -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads