10 years ago I wrote a C++ program to convert programs from my old computer to binary files on the PC. There were several old computers of that kind, so it came down to supporting three different kinds of formats. Unfortunately I had only information on two of them at the time. It did its job, but finding the correct settings turned out to be very hard for users who did not know all details of the tape format. Now it has been high time to keep my promise to write a better and more intelligent program.
Getting the data off the tapes is the easiest part: Hook up the tape recorder to the PC's sound card and sample them as WAV files. The raw samples usually don't look very good. They come from more than 30 year old tapes and analog tape recorders. This is why some filtering was in order. Even the old program did a good job at reconstructing the original digital signal with the help of some mathmatical magic.
Now the buffer should contain a sequence of longer or shorter high/low sequences, representing bits. Plus static at the beginning and the end and possible errors in the data. Simply counting the samples would not have worked.
In the old program the user had to figure out the minimum and maximum sampling settings for both ones and zeros. That involved a lot of trial and error until reliable settings were found, but then it usually worked for all tapes from that computer.
It was not easy and involved something resembling fuzzy logic, but the new program has just successfully converted a WAV recording from my old computer correctly at just the second try. It figured out the correct timing, automatically corrected the inverted signal and then correctly generated a 4096 byte binary file of the program. The second try was only needed to (still manually) set the filtering to a stronger setting. There was a small glitch in the middle of the data.
Now I must wait fot WAVs from other computers to test the other formats, but I think the concept works. Getting the binary files onto the old computers actually is very easy. The program can generate a new WAV file from the binaries, in any of the three formats of course. Save them to tape or play them directly to the computer and they will load.
This way we can even program conveniently on the PC. I Use Visual Studio, a special little C compiler and an emulator for testing. When I'm finished, I just create a WAV from the binary file and then can import and run it on the real thing.
It's amazing, but most of the tapes still load into the old computer as they are. They were not the best quality tapes to begin with and the oldest programs are from 1978. It's really a small miracle that they still load. Other users were not so lucky when they brought back their old computers from the attic.
Never seemed to be too successful at taking on Intel. Motorola gave up long ago. Now Intel will definately have a monopoly. Never really liked the Intel chips, but they were selected for the first IBM PC, and the industry has not reall looked back since them. From what I remember Intel was able to provide an 8085 in a 40 pin plasitc package, while the Motorola 68000 was in a 64 pin ceramic package. The 8086 was the same except is was really 16 bit, and in a 48 pin package. IBM was so cheap that they even did not run the chip a full speed.
That sucks. I use AMD CPUs (and it looks like I'm the only person doing so).
".45 ACP - because shooting twice is just silly" - JSOP, 2010 ----- You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010 ----- "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass." - Dale Earnhardt, 1997
I've given up on pretty much everything except Intel motherboard (actual Intel boards, not third party boards with Intel chipsets) and Intel processors. It isn't really AMDs fault, but rather the motherboard manufacturers - they are all just way too hit or miss for me. Even the high end boards have way more problems than tried and true genuine Intel reference boards.
I gave up when I had some issues with RAID arrays, two boards in a row with two different manufacturers that caused me to lose a lot of data that was SUPPOSED to be protected with RAID redundancy. Unforunately the controllers had issues and I lost quite a bit. RAID controllers seem to be particularly bad on third party boards...I just don't have time for this - Intel appears to be VERY diligent in testing their boards, so I've stuck with them.
"as the chipmaker struggles to find a role in an industry increasingly focused on mobile and away from traditional PCs"
That's once again hype - yes mobile is blooming but most/real work done on traditional PC's.
Yeah, not surprised. I've built several desktop computers for myself and the AMD machines I've built died within two years. Of the four Intel machines I built, only one died and that was after four years; I put the others into retirement after five.
For Bruce Schneier, quanta only have one state : afraid.
To succeed in the world it is not enough to be stupid, you must also be well-mannered. -- Voltaire
In most cases the only difference between disappointment and depression is your level of commitment. -- Marc Maron
Weird, I have not lost any of my AMD PCs, I still have working K6-II, Duron 600MHz, Athlon XP 1700+ (with a small part of the silicon chip missing, but still working), Phenom 9850 BE, Phenom II 975 BE. Over the time power supplies and motherboards died but none of the processors. Starting with the Athlon they were all pretty heavily overclocked - max with basic air cooling.
Except for 1 NVidia card (8800GT, that is one good card), all my graphics cards were ATI. I have lost only one of them, due to fan melting (literally) twice and then, on the second go, trying to remove the radiator myself, by hand. The first fix was done locally and they kind of glued the radiator with epoxy and used too much. Let's just say that when the radiator came off it took some SMDs from the PCB surrounding the chip with it.
I now use ATI graphics but Ivy Bridge i7 - WoW runs about 50% more FPS on Intel compared to AMD processors and that's the only gaming habit I still afford.
Last Visit: 31-Dec-99 18:00 Last Update: 29-Aug-14 11:24