Hi
Wondering if anyone reading this can walk me through handling decoding address lines on the TI.
Looking to possibly add a A/D convertor for example.
I assume I would have to use something like a 74ls138 decoder but not sure how to use the truth table to address the ti memory, say at the end of expansion memory.

Exactly how can I place data at a specific address block?


If someone out there has any examples of how this was done? write ups etc

Please share them.

Years ago there was a clock/ A/D card that did this for example.
( couldn't find a schematic)

I don't know if anyone did a write up on this, in detail .


Steve

Hello every one, i discovered that triplr tech card no work at 100%.. the speech on, buffer print i no tested.. clock no working.. i replace battery but never..
when i try at set date using open command
example 10 open #1:"clock" i have i/o error .. broken the card??

Hello everyone, i have two rs232 broken.. one is ti and one is Corcomp. All two present equal problem.. when i insert in PE Box the Ti99 light on but go in crash.. no video present.. only light blue color on screen.. I for test i check many component on board and discovered that if i leave IC 74ls125 the TI99 start at working.. (obvious the cards no work). If i understood well seem that the signal extint stop the autostart dsr card on PEbox and crashed all.. any idea for solve this problem??

Recently I was asked about programming TI 2532 eproms with a eprom writer that is not configured to write them but can write 2732's.

The answer is to construct an adapter.

I've used one for years on a vintage programmer, that was recently replaced.

To make an adapter you need two 24 pin IC sockets. One with solid pins and one normal one.

Plug the regular socket in the one with the solid pins. But Bend out 3 pins,
18,20, and 21

I'll call the top socket pins T and the bottom pins B

Connect as follows:
18B ----> 20T
20B ----> 21T
21B ----> 18T

That's it. The only other concern is the programming voltage.
A 2532a is 21V and a 2532 is 25v

Your programmer must be able to have a setting for 2732 that will supply the correct programming voltage.

One final thing, you must attach the top socket to the bottom socket.
Not shown in the photo is wire wrap wire used to physically attach the end cross bars on the top socket through the base holes on the bottom socket. This step is needed because once the programming is complete and you attempt to remove the IC from the top socket without this step you could easily pull the adapter apart.

Attached Files

Thumbnail(s)
   

Recently, I built a 8K eprom cartridge to use the >6000 space available at the cartridge slot.
This space can be used for multiple purposes. You can clone a rare Rom based cartridge or write your own.
This project uses a spare TI Invaders cartridge, though there are a few others that will work as well.
If a socket is used on the board, different cartridge roms can be exchanged on the board to change applications easily. There are also 4 Grom spaces available, these can also have sockets installed and will allow up to a possible 4 more titles on the menu along with the eprom at >6000
It appears groms have internal pre-assigned addresses so some will conflict with each other.
What's needed: a 2764 eprom(s) , a TI Invaders cartridge, optional sockets and either a eprom programmer, or a friend with one, along with soldering and desoldering skills and the necessary equipment to do it.
Dumps of Rom only cartridges are available online.

I created a PDF to help a fellow TI er build one, that I can make available here if possible. Otherwise, PM me and I'll send it to you.
* I did upload the pdf, it's attached to a message after this one.
Steve

Attached Files

Thumbnail(s)