| ??? 04/13/06 16:08 Read: times |
#114226 - question Responding to: ???'s previous message |
Erik Malund said:
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I think that if I REALLY scrounge around in boxes etc I might find a HMOS '51 and a 8255, it would be totally absolutely crazy to use them. Why is that? If you have to build ONE of something, and you already know that ONE can be made to work with the HMOS 805x and an 8255, code already exists and is on hand, and you want it completed by tomorrow, noon, wouldn't it make sense to use what's already on hand and been shown to work? Erik Malund said:
I always wonder why someone want to save $1 for a decoder and use a 8255 "on hand" instead, then pay $10 for the aspirin needed to handle the use of the 8255 that saved $1. There's always more to replacing an 8255 than just a decoder and a single register. Now, I'm more or less in agreement that an 8255 is not the best choice for parallel I/O, but, if it's been shown to work, why mess with a known and understood design? Erik Malund said:
A good example of so called "savings" is that since an Atmel 'S' type cost $1 less than a Rx2 type many spend $20 building a programmer for the 'S' which would not be needed if they used a Rx2. > I've got to agree ... Unless the programmer's already on hand, there's no point in trying to save $1 if it reduces the need for programming hardware. That's certainly the case with a one-of-a-kind project. Erik Malund said:
Erik PS: the $ figures above are approximate. However, Erik, many of these inquiries are from people who have designs they're given by someone else, and they want to build THAT. If they had a boss who was willing to spring for a PCB and the latest technology, do you think they'd be here asking the questions they ask? RE |
