Altair Emulator enhancements - progress report - questions

From: ajp166 <ajp166_at_bellatlantic.net>
Date: Tue Sep 12 11:20:27 2000

From: James Willing <jimw_at_agora.rdrop.com>
To: Cini, Richard <RCini_at_congressfinancial.com>


>The paper-tape based versions of Altair BASIC polled the 'sense
switches'
>to determine the type of I/O to be used, and by inferrence the port
>numbers. It contained its own I/O routines.


Casette versions polled the sense switches (port FFh) as well.

>
>> What port locations were generally used to service
>> serial ports used for console I/O?
>
>The closest thing to a 'standard' selection (also used in the disk based
>versions of BASIC) was for the 2-SIO board which was located at ports 20
>and 21 (octal).


Or the MITS SIOA and SIOB at 0/1 with one of two possible status bit
combos. THe SIO had a early rev that move the sense bits around.

>> Does anyone have a working set of CP/M
>> binaries that I can load into the emulator?
>
>For what disk sub-system? (Mits, Tarbell, etc...???)


Do you plan to emulate the BIOS IO to the ports and disk system?

Allison
Received on Tue Sep 12 2000 - 11:20:27 BST