Emulating 88-AD/DA on the clone

General discussions related to the Altair 8800 Clone

Emulating 88-AD/DA on the clone

Postby mcleinn » May 21st, 2021, 8:47 pm

Dear community, dear Mike,

I wonder what would be the best way of emulating a 88-AD/DA board with the clone.
Given we don't have the S-100 bus, what would be the most authentic vs easiest way
to connect a bunch of external DACs and ADCs? External hardware on the serial port?

There is a code sample here: https://altairclone.com/downloads/compu ... _02_10.pdf
on page 16 of the PDF (original counting: FOURTEEN)

Thank you! Tobias
mcleinn
 
Posts: 8
Joined: July 3rd, 2018, 7:34 am

Re: Emulating 88-AD/DA on the clone

Postby AltairClone » May 22nd, 2021, 2:02 pm

You’ll probably have to use the serial port to talk to a smart AD/DA board you make.

Mike
AltairClone
Site Admin
 
Posts: 632
Joined: April 5th, 2013, 10:55 am

Re: Emulating 88-AD/DA on the clone

Postby mcleinn » May 25th, 2021, 9:32 am

Probably going to do that, the downside is, that I cannot address which DAC to write or ADC read from via the device number.
As with the original card, there will be several input and output channels.

So I wonder, how to best control the multiplexer of the 88-AD/DA. Is the only option to use a second serial port as control line,
or can I use some other signal line... INTE would probably work, like with the music system, but not really authentic? Are there
other lines on the front panel I can take for addressing?

In general, it would be cool to be able to assign Altair device IDs freely to I2C bus addresses via the configuration menu,
then one could use the I2C bus to connect (imitated) hardware

But judging from other posts, it sounds as if the 8800c is the way to go for such customization?

Thank you
mcleinn
 
Posts: 8
Joined: July 3rd, 2018, 7:34 am

Re: Emulating 88-AD/DA on the clone

Postby AltairClone » May 26th, 2021, 6:51 pm

You can control the RTS output under 8080 program control on serial ports 1 and 2.

The 8800c is a real Altair/S100 bus computer, so you could install the real 88-AD/DA card if you wanted.

Mike
AltairClone
Site Admin
 
Posts: 632
Joined: April 5th, 2013, 10:55 am


Return to General Discussions

Who is online

Users browsing this forum: Google [Bot] and 14 guests

cron