TMS9900 Application Sheet

[+dhe]

I found this "Application Sheet" online - is there a treasure trove of TMS9900 Application Sheet's hidden online somewhere?

 

Stack Structures for TMS 9900 Application Sheet.pdf

[ti99iuc]

It is in WHtech I think, anyway interesting and it is good to have it highlighted here.

Edit:
here, indeed: http://ftp.whtech.com/datasheets and manuals/Specifications/

Edited October 17, 2022 by ti99iuc

[+Ksarul]

I suspect most of the 9900 series application sheets aren't online, although all of the chip datasheets are.

 

On odd 9900-family chips, I just found a source that actually has apparently-original TMX9909 chips in stock. They are on the seriously high side cost-wise though, as the source wants about $60 each, with a minimum order that puts the total cost into the 2K range. . .much worse price-wise than the $12 I paid for the last one I found.

[+FarmerPotato]

I wondered what might be in that one. One seller wants a lot of money for it. 
 

This application sheet is much like  content in the Software Development Handbook.  You’d also have seen it and much more in the 990/189 users manual.

I think that’s the role of Application Sheets. Short digest of an idea.  

 

There  is a lot of preserved 9900 “heritage” on stacks and position-independent   code in the Executive Runtime and Microprocessor manuals. And maybe that’s all taken from the DNOS manuals, I dunno yet!  
 

I was amazed at how much more there was to study outside my little home computer world. 

[apersson850]

They show a use of POP and PUSH designed for saving the return address only. The method of letting the stack grow towards higher addresses then has its advantages.

But if you want a stack to work as a data stack, it's more efficient to let the stack pointer point to the value currently at the top of the stack, since you otherwise have to access it with an indexed address @-2(SP). *SP takes less space and is faster.

Yet another method is the one of Forth, where you have two stacks, data and return stacks.