Jump to content
IGNORED

The TMS9900 Cheat-Sheet


SteveB

Recommended Posts

Well this is all public information but here is what's in my source code.

Just read them upside down and it all make sense.  :)

 

HEX 
    1300 CONSTANT RS232/1    \ RS232/1 card address
    1500 CONSTANT RS232/2    \ RS232/2 card address
      40 CONSTANT TTY1       \ 40 = uart#1
      80 CONSTANT TTY2       \ 80 = uart#2

\ card control bits. CRU base (R12) set to 1300/1500 
       5 EQU -CTS    \ "negative" CTS (low=clear to send) OUTPUT!!
       7 EQU LED     \ CARD LED on/off 


\ 9902 UART control bits. CRU base (R12) set to 1340/1380/1540/1580
DECIMAL
       13 EQU LDIR     \ "load interval register"
       16 EQU RTS      \ request to send
       18 EQU RIENB    \ rcv interrupt enable
       21 EQU RXRL     \ receive register loaded bit
       22 EQU TXRE     \ transmit register empty bit
       27 EQU -DSR     \ NOT data set ready
       28 EQU -CTS     \ NOT clear to send INPUT!! 
       31 EQU RESET    \ 9902 reset bit

 

Edit:

I had to double check the comments.  

Note  bit 5 is OUTPUT  and bit 28 is INPUT  (readable)

This is a confusing bit for doing RTS/CTS handshake. 

  • Haha 1
Link to comment
Share on other sites

On 3/17/2024 at 4:53 PM, TheBF said:

 

HEX 
    1300 CONSTANT RS232/1    \ RS232/1 card address
    1500 CONSTANT RS232/2    \ RS232/2 card address
\      .
\      .
\      .

 

 

Usually, 1300 is the CRU address for both RS232/1 and RS232/2 and 1500 is the CRU address for RS232/3 and RS232/4.

 

...lee

  • Like 2
Link to comment
Share on other sites

1 minute ago, Lee Stewart said:

 

Usually, 1300 is the CRU address for both RS232/1 and RS232/2 and 1500 is the CRU address for RS232/3 and RS232/4.

 

...lee

Quite right. I don't have a second card so that error never was tested.

Good catch.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...