16 bit / 32K daughter board.

[+dhe]

I've posted a number of times, how much I love my Top Radio Supply Daughter Board.

 

To gauge interest, I'm putting up a poll to see how many would be interested in a daughter board arrangement for the TI if one became available.

 

Here is the text of a Randy's Rambling's about the board from computer shopper days.

 

Multiplan:
Sort 51 items in spreadsheet
(14 chars long)
27.3 secs
39.3 secs

 

Editor/Assembler:
Assemble Fast-Term
10 min. 48 secs
12 min. 17 secs

 

This product came to light from a conversation that was held a long time ago by myself, Steve and Andy Cooper (the p-System wizard of the TI Community). Andy made the realization while playing with a bus analyzer on a TI system that if you do certain things to the control lines the processor runs at the full bus speed of 3 MHz (which is the speed that the system ROM and the scratchpad RAM get accessed at). Steve and I got to thinking that if someone could put expansion memory inside the console across the 16-bit bus Assembly Language performance of the 99/4A could be dramatically improved. The result is the 16/32memory card which does place the 32K of memory across the 16-bit bus and does improve performance.You may have noticed that I said "Assembly Language performance" versus Basic/Extended Basic: Both Basic and Extended Basic are under the control of GPL and as such are slow (though Assembly Language routines called from these environments should run faster with the 16/32 Memory Card installed).

How much faster do programs run with the 16/32 installed? Examine Table 1 for some examples of the performance increase under the products listed.

 

Right about now you're probably asking "How compatible is this product? 70%? 80%? 100%? What hardware or software won't work with this card?" The answers are as follows: The card is 32K of memory that sits inside your console across the 16-bit bus, giving you increased speed and performance. If the code that you are running has software timing loops that are at all critical there is the likelihood that the code may not run properly, which is to be expected. So far, I myself have not run across a piece of legitimate software that has NOT worked with the 16/32 memory card. (I did try a "cracked" version of Atarisoft's Dig Dug but it died as it put up the playing field, and no, I do NOT have that "cracked" version of code in my library, thank you.)

 

If you have any of the 128K cards there is a little surprise waiting for you: with the 16/32 card install edit will NOT recognize it as the control line is not brought out. As a matter of fact you can have a 32K card in your PEB and a 16/32 in your console and it will ignore the 32K card as well. Should you desire to have the old 32K card available, Top Radio Supply will tell you how to install a switch to do this so your 128K investment isn't thrown out the window.

 

I recommend the installed version unless you have access to a vacuum desoldering station or are willing to spend several hours using solder-wick attempting to desolder the TMS9900 processor from the console's motherboard. (I managed to wipe out one of my spare consoles attempting to desolder the TMS9990 from the motherboard.) Also, the kit comes with only a 30-day warranty; and if you somehow manage to mung(modify until no good) your console during installation Top Radio Supply will charge $50 to rectify the situation. The assembled version (where you send in the console) carries a 1-year warranty and in addition to the warranty the power supply is modified to reduce heat dissipation and to handle the increased current load required by the 16/32. Fortunately the 16/32 uses CMOS 6264 8K × 8 SRAMs so it doesn't draw that much power.

 

I have been running my own system with a 16/32 Memory card for over three months now and I can honestly say that it works. I have also noticed that my system doesn't crash as much as it used to. As a matter of fact during the benchmark test of assembling Fast-Term the stock system configuration would lock-up right after it displayed the "0000 ERRORS" message, while the 16/32 went to a clean end. Even if I didn't have a hand in this, I'd still buy it!

[+OLD CS1]

It does sound interesting.  Since the 32k address space is not routed out the expansion port with this installed, it sounds like you could use this with a nanoPEB or CF7+ without removing the on-board 32k RAM.  But it also seems like that would preclude using a SAMS with the system.  Irrespective, I might could be interesting in installing one on one or a couple of my consoles.

[Shift838]

1 hour ago, OLD CS1 said:

It does sound interesting.  Since the 32k address space is not routed out the expansion port with this installed, it sounds like you could use this with a nanoPEB or CF7+ without removing the on-board 32k RAM.  But it also seems like that would preclude using a SAMS with the system.  Irrespective, I might could be interesting in installing one on one or a couple of my consoles.

I believe a simple switch would also allow the expansion ram to be enabled or disabled if added to the circuitry.

 

 

[+FALCOR4]

I have one installed in a console that I used BITD when I was coding in assembly; it still fires up and works today.  I used it then because it was a bit faster assembling programs (before the emulators we have today).  It had the switch on it, but I never knew what it was for.  Thanks for the info. The P/S mod that I have in the console was a resistor inline on the incoming power line.  Were there other modifications besides that?  Just curious.  That resistor did get hot enough to slightly melt the plastic case bottom side as I remember!