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Old 06-10-2008, 04:45 AM
Forbin376 Forbin376 is offline
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Join Date: Jan 2008
Location: Oregon
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Default MITS Paper Tapes

I take it that you have access to a working paper tape punch! I'd be happy to test a tape for you. I have a Remex high-speed paper tape reader interfaced to a MITS 4-PIO board. I have not used it in some time (many years) but it has been well stored. My Altair A is up and running my B is not at the moment. If I recall correctly the MITS Altair BASIC uses a two stage loader. The first block of the tape is read by the boot strap as binary byte-by-byte data that is copied into memory by the "toggled" in loader or a PROM boot loader program. Once that loader is in - by counting a fixed number of bytes - it is "jumped" to and begins the actual loading of BASIC. This second loader reads checksumed records and at the end jumps to BASIC itself. I'd need documentation on where the initial loader should end up in memory and how large it is. Does someone have this information or know where it can be found? I no longer have any paper tapes myself which is sad. My mailing address is:

Frank Barberis
111 SW 5th Ave.
Suite 800
Portland, OR 97204

Oh what has been lost: Once upon a time I had a Mylar paper tape of the MITS 12K BASIC Version 3.2 that was loaded into my Altair 8800 A by an ASR-33 Teletype and a MITS 2SIO board!
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