Download Ipso Facto Issue 5
Transcript
r-IACHIN~ OR ASSEIilBLY LANGUAGE CONT'D machine code, especially as your programs exceed the 10-20 byte size. Anyt'lay, how many of you can really think in machine code when reading, say, a 256 byte program written by someone else? Think about it. I think the best way to illustrate my point is with an example, and 2n excellent one has coce to hand. Recently, two large circulation magazines, POPULAR ~L~CTRONICS and DR. DOBB'S JOURNAL, published an interestin.e; monitor program ~or the 1802 (Ed, you wer-e going to tell me why they both printed it?). Unfortunately (in my opinion), both of these magazines published only an uncommented hex dumPTIsting of this program. How many of you, when faced with this type of program docurnentation, decided that it woul.dn t t be wor t.h the effort? HO\'I many others tri ed it, but couldn't get it to work right? And finally, how many of you began to dis-assemble, and comment the program, in order to figure out how to get it working on your particular 1802? \'louldn' t i t have been nice to have all that information in the original listing? In this issue of IPSO FACTO, you will find a dis-assembly of Ed McCormicl:'smonitor program. I want you to compare this form of documentation with the hex dump published by PE and DDJ. I hope this example makes my point. SI~P1Z APPLIC1TIONS In order to maintain the involvement of those not (yet) interested in a general purpose computer system, we intend to put more emphasis on simple, fun-type applications, requiring only an 1802, 256 bytes of memory maximum, and perhaps a few bits and pieces of Lnt er-f'ac e har-dwaz-e , The first one is in this Issue: The 8 digit hex display for under ~10. This simple application \'l/ill be extended in the next issue, to become the display for a Raal Time . Clock. You will also find a speed control for those cheap 6 Volt DC motors, which requires only a power transistor, a door bell control based on your 1802, and a sump pump t i ner-, How about you? Let's hear about your application: the simpler the better. Remember: the best way to learn is by doing. I will apologize at this point for the delay in getting out Issue J4; we had a few printing problems. I expect we will soon be back on schedule. NETRONICS, ANYONE? Speaking of schedules, has anyone received a news bulletin from Netronic's Elf User's Club? I have had several people ask me this question. Their memberships, at 83 eaCh, po back about 8 months. Perhaps someone from Netroni cs R&D, Ltd. wouLd care to reply c/o this Editor? (3)