altair micro IO port's

Discuss the new Altair 8800 Micro

altair micro IO port's

Postby galaga » Mar Wed 09, 2011 2:26 am

can some one tell me about the altair micro IO port's
i know theres 255 on the 8080 but some ppl used to make easy by using one address per port.. so 8 etc.
is there a memory and IO map..
thanks matt
User avatar
galaga
 
Posts: 62
Joined: Feb Fri 18, 2011 7:29 pm

Re: altair micro IO port's

Postby wd5gnr » Mar Sun 13, 2011 10:12 am

The box emulates an SIO which used port 0x10 and 0x11. Port 10 was a control port that does not actually do anything write-wise in emulation and port 0x11 is the serial data in/out port. Reading port 0x10 has bit 1=TX ready and bit 0 = RX character available. Not all versions of the firmware handled this right but later ones do.

Port 0xFF reads the sense switches as I think you know.

Other than that, there's no other ports emulated. As for the memory map its RAM 0-32K. That's it until Vince ships the new memory add on board or if you do like at least one person I know and hacked up another 32K RAM chip.
wd5gnr
 
Posts: 69
Joined: Aug Sun 29, 2010 11:33 pm

Re: altair micro IO port's

Postby galaga » Apr Sun 24, 2011 8:26 pm

its all a bit confusing in basic8k i can scan the ports and the only ones the change are 16,17,18,255 but the basic get's to the key data before i can read it :(
i'll have to use asm?? have you found good altair assembler/monitor program??
User avatar
galaga
 
Posts: 62
Joined: Feb Fri 18, 2011 7:29 pm


Return to Altair 8800 Micro

Who is online

Users browsing this forum: No registered users and 3 guests