Re: Virtual serial drive

[Riccardo <rigreco.grc@gmail.com>]

Il giorno sabato 8 settembre 2012 20:19:57 UTC+2, Riccardo ha scritto:
> Il giorno sabato 8 settembre 2012 12:14:51 UTC+2, Riccardo ha scritto:
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> > Ok, I restart to studied "Inside the Apple IIc" by Gary B. Little 1985, Chapter 11, "The Serial Interface Ports", from page 299 to page 324, it's the great work. And reopen my old book: "Sistemi a microprocessore" by R. Baranzini, D. Capezzuto, G. Dugnani, HOEPLI 1986.
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> > First:
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> > - //c have two 6551 ACIA (Asynchronous Communication Interface Adapter)IC
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> > - PC/MAC typical use Intel 8251A USART (Universal Synchronous Asynchronous             
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> >   Receiver Transmitter)IC, i think.
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> > both IC implement AIA RS-232-C and have two phases:
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> >  Programmer and Communication
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> > Right, my first question:
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> >  At page 307 Figure 11-3 of "Inside the Apple IIc" book, show max set-up speed to 19200 bit/s, but i great currently work up 115200 bit/s with ADTPro, Why ?
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> > see you to next step.
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> > Thanks
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> > Riccardo
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> Thanks,
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> Another choice:
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> 1) With Prodos Utilities v 1.0 1984 Apple //c original:
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> 110 - 300 - 1200 - 2400 - 4800 - 9600 - 19200

2) with Prodos Utilities v 3.1 speed set-up at:
50-75-110-134.5-150-300-600-1200-1800-2400-3600-7200-9600-19200

2^4 = 16 combination bits, it's clear that utilities do not use any combination, by the way:
at combination 1111 of the 6551 control register, what speed correspond?  19200 or 115200 bit/s
Is it possible exists variant of 6551 IC built in //c ? 

Ric.