TI Mini Expansion System

[Artoj]

8 hours ago, Ksarul said:

The complete explanation for how it works is in an early issue of TI-Revue.

Thanks Ksarul, I need to look at this as well, clarity is best served with dessert, at least I do not need to write 4 pages of worded explanation or 1 page of operations on binary counters and memory addresses. Regardless, I am happy to release all the files if anyone is interested in building it. It was Mr Martin who unlocked the GROM, my gratitude is to his great work.  

As this was unfolding I upgraded JOYPORT to version 4.0, it has a complete RS232(in/out), Light Pen, SDA/SCL port, Parallel port (Out Only), 2 Atari Joystick ports and a 31 switched input keyboard port. I will make it a 2 way parallel port in the next version, then I will get this one made ASAP. Regards Arto.     

[+Ksarul]

Oddly enough, TI actually made and sold GROM simulation cartridge boards to developers (EGROM boards). I have a pair of the bare boards squirreled away somewhere. A lot of the true prototype cartridges in the wild are also built on these boards.

 

Mr. Martin's board was definitely an outgrowth of those TI boards, as one of the most common modules built on them were the Advertizer cartridges circulating in Germany.

 

Most other cartridges identified as prototypes are actually from qualification runs (100-150 examples in a run) made to test the production equipment and parts before initiating full production. I have a couple dozen of this type, but only 3-4 of the ones built on the EGROM boards.

[Gary from OPA]

2 hours ago, Ksarul said:

Oddly enough, TI actually made and sold GROM simulation cartridge boards to developers (EGROM boards). I have a pair of the bare boards squirreled away somewhere. A lot of the true prototype cartridges in the wild are also built on these boards.

 

Mr. Martin's board was definitely an outgrowth of those TI boards, as one of the most common modules built on them were the Advertizer cartridges circulating in Germany.

 

Most other cartridges identified as prototypes are actually from qualification runs (100-150 examples in a run) made to test the production equipment and parts before initiating full production. I have a couple dozen of this type, but only 3-4 of the ones built on the EGROM boards.

yeah, i used to have a couple of these myself, i had a prototype TI Invaders one on a EGrom board.

[+Ksarul]

10 hours ago, Gary from OPA said:

yeah, i used to have a couple of these myself, i had a prototype TI Invaders one on a EGrom board.

I just received one in the mail today built up as a TI writer cartridge with only English and German as selection options. . .along with a Logo II module in German--with real GROMs, so it was a qualification run cartridge. Interesting that I received one of each type of TI proto along with a fully built-up Heiner Martin board the day after I posted some data about the various types of cartridge boards. . .LOL

[Gary from OPA]

11 minutes ago, Ksarul said:

I just received one in the mail today built up as a TI writer cartridge with only English and German as selection options. . .along with a Logo II module in German--with real GROMs, so it was a cartridge qualification run. Interesting that I received one of each type of TI proto along with a fully built-up Heiner Martin board the day after I posted some data about the various types of cartridge boards. . .LOL

looking forward to the dumps and photos when you bored.

[+Ksarul]

The Logo II cartridge also came with a German manual, published in Switzerland in late 1984. I had never seen that book referenced anywhere, so it is one more for my bibliography of TI books. It also had a handful of other Logo books in German, but they weren't TI-specific (although some did reference it).

[Artoj]

Hi All, I just finishing the Translation of the article, regards Arto.

 

GROM/ROM
by Heiner Martin
(from TI-Revue Issue 5-1985
(translated from German)

 

What is missing? Each Grom has an internal counter for addressing the desired memory location, which can be set via the data lines, which automatically counts by 1 each time data is read, and whose status can also be read out again. And this reading of the address was missing.

 

Yes, since this works, the only explanation is that the three GROMs contained internally in the TI 99/4A output the address (even one at which they do not normally respond).

 

This lack of reading the address made the circuit much simpler and so a board could now be developed for the module port which covers the GROM and ROM area available there. The size was chosen so that it fits into the usual module housings.

THE CIRCUIT: _

 

The ROM area at the module port ranges from >6000 to >8000, i.e. a total of 8KByte, in which assembler programs are stored. A 2764 eprom was provided on the board for this purpose, although a 2732 can also be used without modification for small programs. In addition, with the second half of the 74LS139, the addresses are decoded to 2KByte blocks for own constructions.

 

The GROM range covers the GROM address >6000 to >FFFF. First of all, however, a counter consisting of 4 74LS161 is available for the groms. These are connected in the counter function as a completely normal 16-bit binary counter. If the GLA line is set low, i.e. active (via the second half of the 74LS139 from the signals GS, DBIN and Al4), the upper 8 bits of the counter take over the state of the lower 8 bits and the lower 8 bits are loaded with the value on the data lines. The GC'LK line becomes active with every read access and increments the address counter. The outputs of the address counter serve as address lines for one to 5 Eproms 2764, whereby the decoding into 8KByte blocks is carried out by a 74LS138. However, the following is wired on the board only the GROM with the address >6000 or, with minor modifications, a 27128 can also be used for GROM >6000 and GROM> 8000.

 

THE ASSEMBLY: _

 

The board must be double-sided, preferably with copper-plated through holes. The side with the lettering HM is the lower solder side. The assembly is shown in the plan, so that no further explanations are necessary here. If a 27128 is to be used in the GROM, the tracks shown as dashed lines in the circuit diagram must be connected or disconnected, i.e. the line leading from the 74LS138 at pin 12 and the connection between pins 26 and 27 must be disconnected. The line leading directly to pin 26 of the eprom is connected to pin 26 with a little solder and the hole next to pin 15 of the 74LS138 is connected to the line to pins 20 and 22 of the eprom. If further eproms are to be installed at the Grom addresses >A000, >C000 and >E000, they are to be stacked on the 27128, i.e. the eprom is simply placed on top and all pins are soldered, except for pins 20 and 22. These are connected to each individual eprom and then connected to the corresponding output of the 74LS138, i.e. the points labeled GSA, GSC and GSE in the circuit diagram.

 

THE APPLICATION:

Independent assembler programs can be placed in the ROM area. It should be noted, of course, that none of the other auxiliary routines such as KSCAN, VMBW, VSBW etc. are available. Also, the complete screen layout with the loading of the character tables etc. must be carried out by the user. The jump from the title screen is possible with almost all consoles in Germany (except the consoles that report themselves in the title screen with (c) 1983). To do this, the following header must be set:

 

AORG> 6000
DATA> AA01 Header and version 
DATA >0100 Number of programs
DATA >0000 (power-up routine) 
DATA PRGLNK program link 
DATA >0000 (DSR link) 
DATA >0000 (subroutine link) 
DATA >0000 (interrupt link)

PRGLNK     DATA PRGLK2 (0 if no 2nd program)
                DATA ENTRY (jump-in address)
                BYTE 4 (name length) TEXT "TEST" (name)

 

The pointers to other lists given in brackets in the header cannot be used in the ROM of the module port, but exactly the same header is used in the GROM and also in the DSR routines (e.g. disk controller). Which brings us to the GROM. You can create your own GPL programs in this area, which is now possible since the secrets of this programming language have been revealed. If the program is accessed via the simulated

GROM, the program can be run on any console.

 

This board now really enables new program developments for the TI 99/4A, which are on the same line as the original TI modules, without having to rely on special components from the former manufacturer. A first new GPL program for this board is already in progress, it converts LIST files in Variable 80 format back into executable programs. You could also write a program to convert the Basic code into TI-Basic.

Another application for this board is left to the imagination of each individual. Provided there is a certain demand, I would be happy to have copper-plated boards produced, but the distribution would then have to be carried out by a specialist dealer for reasons of cost.

 

Heiner Martin

 

[+Ksarul]

Digging around, I found some additional data on Heiner Martin's board (I received it from @Flottmann1 a while back) which might come in useful. I think the file describing the Type 2 board was a translation I did quite a while back. . .

 

I also included images of an EGROM board with Advertizer on it for comparison, along with the Advertizer manual, which is relatively hard to find. Note that this weird TI cartridge does NOT show up on the title screen--it just adds a bunch of routines to TI BASIC.

heiner_cartridge.pdf Heiner Martin Cartridge Board-Type 2 (English).pdf Advertiser.pdf

[Artoj]

3 hours ago, Ksarul said:

Digging around, I found some additional data on Heiner Martin's board....

Wow, great stuff, I'll check it out. In the mean time here is a plug-in board, it stacks on top of GROMO, the extended header pins are on the bottom right chip (U1) and the 4 address pins, easy to expand without messy soldering and bending pins. Regards Arto. 

 

Edited March 19 by Artoj

[Artoj]

Hi All,

I have tentatively designed the input section of the parallel port, working on the software so you can set the port as in or out. Slowly getting there, I have wanted to make this interface since about 1986, I just never got around to it. Now to integrate it into the final JoyPort V5 and then get it made, then comes the really fun part, testing, checking and software tweaks. Making the plan is half the fun, building it is such a pleasure and then getting it totally functional is the icing on the cake. Regards Arto.  

 

[Artoj]

Hi All,

Version 6 of the TI99JoyPort has the full compliment of Ports now - Light Pen, SDA, RS232 (2 Way), PIO (2 way), 31 Switch keyboard ports, 2 Atari Joystck Ports and a Digital Cassette Port. You will need a small lead to connect the original cassette port to the Joyport input.  You can only select one function at a time safely except the Digital Cassette port which is always available, I hope to get this tested and built soon, I am also working on the software at present. Regards Arto.

 

Here are some pics of the current state.

 

[Gary from OPA]

30 minutes ago, Artoj said:

Hi All,

Version 6 of the TI99JoyPort has the full compliment of Ports now - Light Pen, SDA, RS232 (2 Way), PIO (2 way), 31 Switch keyboard ports, 2 Atari Joystck Ports and a Digital Cassette Port. You will need a small lead to connect the original cassette port to the Joyport input.  You can only select one function at a time safely except the Digital Cassette port which is always available, I hope to get this tested and built soon, I am also working on the software at present. Regards Arto.

 

Here are some pics of the current state.

 

Needs more switches and blinking lights.

[Artoj]

40 minutes ago, Gary from OPA said:

Needs more switches and blinking lights.

I was trying to get more blinking lights and switches, the PCB can fit a few more LOL.. The front area you are talking about actually has a cover, so you can hide it all of it, or you can add more as there is a slot (hidden) that can route every joystick function in real time!!!(mmm thinking.....) I have 2 spare 16 pin sockets, for future functions.  

Actually, you can build one function at a time, as they are all independent, so if you only need the RS232 then that is all you need to build. It was made to cover many uses, so as an example of a  bare bones board, it would only be the 5 diodes and the 1 Atari port.  

[Tornadoboy]

Damn... on top of being useful, it's extremely cool looking!

[Artoj]

Hi All,

While studying all the different SRAM systems, especially the Horizon effort by so many great builders and programmers of the TI99 community, I have been inspired to make a SRAM card as simple as possible to use and program. This card is experimental at present, it has the standard 32k SRAM, plus the ability to switch the 32k in and out with another 15 more banks. I also added the ability to use 16 banks of 8k at >4000 and at >6000 if required using links. It can run off 9vdc or the console power, with battery back up if required as well. It does not have a DSR.

The CRU addressing is at >0400 and each bank is selected by SBO and SBZ. Still working on the prototype design, but I hope to test it soon. Regards Arto.   

[Artoj]

Hi All,

I am deciding to get a few different cards(2-4) made with JLPCB, here is a list of some TI Cards I am contemplating on.  

 

Mini PE Boards

TI Music Card V3  (based on the Forti card)
TI99-Wire Interface V3 (based on R Mudie)
TI99 ADC V2 (Based on G Emmich & T Albanese)
TI99 Clock V2 (Based on J Pain)
TMS9995 SBC V3 ** Stuart Conner design adapted for the TI99 bus **Untested** 
TI99-HDR Pins (port to pin for testing)
SRAM99 V1

 

Cartridges 

TI99 EPROMMER V1a (based on H Martin & R Kleinschafer)
EPROM Cart V4 (Based on J Guidry, S Conner, M Brent, T Knerr)
EPROMOX Cart V1 (based on ROMOX)
TI99 Wopper V1 (based on C A Bowman Whopper)
TI99-GROMO V1 (based on H Martin)
TI99-GROMOStack V1

 

Joystick Port

TI99-Joy-RS232 V3
TI JoyParPort V3 (using EDE300)
TI99JoyPort V6 (some parts need Testing)
TI99JoyPortPlug 1a

 

How my efforts usually work is:

V1 usually means a new prototype or if I have the circuit diagram then I have yet to test it and I might have missed a few things or it is generally that it is my first run and the boards will only need cosmetic changes. 
V1a or V1b etc it means I have had to change some logic or rewire something from the original prototype.
V2 means it good to go as a basic unit.
V3 I have added functionality
V4 ditto
v5 ditto
V6 getting to the end of the design possibilities and most errors should have been detected.
V7 ditto
V8 ditto
V9 and above - Tested and running on working software. 

 

Let me know which ones you are interested in, if you want me to list them as pictures let me know. I have many other cards and designs but I am concentrating on this batch at present, if you want a card you have seen before and is not on the list let me know.

My main design and testing will be with my Ternary Computer Project, the TI99 has been a great sandbox for many ideas and I am happy to share them with the rest of the retro TI99 community, thanks for all your encouragement. Regards Arto.
 

[Artoj]

Hi All,

After reviewing my SRAM design, I have opted for 32 banks of 32k and a separate 8k at >4000 and a separate 8K at >6000 by jumpers (version 2), this should be more flexible and simpler to implement. This way you can use Minimem etc to load in your own and simple bank switching software, using 32 CRU switches. This scheme could be expanded to any size, only limited by the SRAM and CRU bit availability. Full screen video animation is now a CRU bit away. I will make the schematics available shortly. Regards Arto. 

[Artoj]

Hi All,

I am still drawing the diagrams for the SRAM, when I thought to change the form factor for all the MiniPEB designs that I have, when Peter originally designed and made the boards back in the 80's we were putting tape on by hand and keeping things so we could build it the best way we could with the track sizes and rough tech we had in the garage at home. Now that i have redrawn all his boards, which I will keep for prosperity, I looked at the possibility of making a form factor that can be used by the TI community as well. I originally thought that the box size would be 100mm x 260mm on the outside and the PCB would be 110 (96) x 254  , these are tentative dimensions at present. With 3D printers generally having a maximum build of 250mm , it might be prudent to make everything fit to this size. The a size of 100mmx250mm might seem more logical, so as PCB size of 96(110) x 246 as the max would make sense. It would look great as the TI dimensions are 260mm wide. To be more universal the through bus and connectors should be standardised, to this end I should create a prototype board suitable for all the current RH port projects. Here is the 64/64 adapted to this size, it looks like I have enough room to include another peripheral on the same board. What I have in the picture here is a cut and paste attempt and I will work to simplify and add another project with this one on the same board. Regards Arto   

 

[Artoj]

Hi All,

Here is another card with the new form factor(MPEB) with a 2 port PEB, so if you do not have a TI99 PEB, you can now have at least 2 slots with just a console (plus extra power supply). I have gone with the sizes 246 x 96(110) or in inches 9.7 x 3.795(4.33). I will be working on the casing next, then converting all other designs to this form factor. Regards Arto.  

Edited April 17 by Artoj

[RickyDean]

17 minutes ago, Artoj said:

Hi All,

Here is another card with the new form factor(MPEB) with a 2 port PEB, so if you do not have a TI99 PEB, you can now have at least 2 slots with just a console (plus extra power supply). I have gone with the sizes 246 x 96(110) or in inches 9.7 x 3.795(4.33). I will be working on the casing next, then converting all other designs to this form factor. Regards Arto.  

I can see agood use for this in a portable ti. Could use an Ide, Scsi, or both.

[Artoj]

MEGA99 Sram Expander V2.0

 

This is a revamp and attempt at a hardware simplification of the software required to create a large Static Ram pool you can use by switching CRU bits. My first idea was to use 16 CRU bits to switch in the whole 32k (>2000 + >A000 + >C000 + >E000) in consecutive banks. Then I realised if I was using a 1024k Sram chip then I would only use half of the chip (address gap), so I needed to expand it to 32 CRU bits or as 2 Blocks of 16 banks(current design). as this was only 1 Sram chip, I looked at adding another 5 more, giving you a total of 6 Meg to play with or 768, 8k ram banks. 

 

When you boot up the TI it will default your standard usable 32k to SRAM 0 and Block A and Bank 0. You also have access to 2 extra 8K Sram chipS >4000 and >6000, chosen by jumpers on the board and switched in and out with CRU bits(CRU 32/33 still to be added). 

 

As this is a work in progress along with my other projects, I hope to get this unit finished soon as possible, this project only needs one 1024k Sram chip to be usable, the rest of the Ram chips (1Mb and 8K) can be added when and if required.     

 

Here are some of the abstract work.

 

R12 = >0400

 

32K BANKS    SWITCH
-------------    ON    OFF
CRU    0          0    1                Default
CRU    1          1    0
CRU    2          1    0
CRU    3          1    0
CRU    4          1    0
CRU    5          1    0
CRU    6          1    0
CRU    7          1    0
CRU    8          1    0
CRU    9          1    0
CRU    10        1    0
CRU    11        1    0
CRU    12        1    0
CRU    13        1    0
CRU    14        1    0
CRU    15        1    0

 

2 BLOCKS    SWITCH
-----------       A    B
CRU    16        0    1                Default

 

SPARE CRU    SWITCH
------------    ON    OFF
CRU    17        1    0

 

SRAM EN        SWITCH
----------        ON   OFF
CRU    18        0    1    SRAM 0        Default
CRU    19        1    0    SRAM 1
CRU    20        1    0    SRAM 2
CRU    21        1    0    SRAM 3
CRU    22        1    0    SRAM 4
CRU    23        1    0    SRAM 5

 

*** the list below has yet to be implemented ***

 

UNDEFINED (FUTURE EXPANSION)
-------------
CRU    24
CRU    25
CRU    26
CRU    27
CRU    28
CRU    29
CRU    30
CRU    31

 

>4000 BANK    SWITCH    (Currently only by jumpers)        
--------------    ON    OFF
CRU 32             1    0

 

>6000 BANK    SWITCH  (currently only by jumpers)
--------------    ON    OFF
CRU 33             1    0

 

I am still working on the PCB wiring, Regards Arto.
 

[Artoj]

Hi All,

Here is the completed board (V3.0), I will be checking it for problems over the next few weeks before I get a bunch of other boards made including this one. Regards Arto.

 

[Artoj]

Hi All,

The IDE board in the MPEB format has been created, I am leaving some real-estate for possible 32k Sram, RS232 or MIDI, so any suggestions would be appreciated. I would like to think this board with the extra functions would be a very usable TI system. Regards Arto.    

Edited April 27 by Artoj

[RickyDean]

49 minutes ago, Artoj said:

Hi All,

The IDE board in the MPEB format has been created, I am leaving some real-estate for possible 32k Sram, RS232 or MIDI, so any suggestions would be appreciated. I would like to think this board with the extra functions would a very usable TI system. Regards Arto.    

I'd say your going strong, like to see the SAMS as an option, but it's looking good.

Edited April 26 by RickyDean
spelling

[Artoj]

On 4/27/2024 at 4:04 AM, RickyDean said:

I'd say your going strong, like to see the SAMS as an option, but it's looking good.

Thanks Ricky, I think that a SAMS design would be the IDEAL choice to go with an IDE board. One caveat is that I will be stretching my 2 sided board designs to a new limit, still it is a great test for pushing myself towards excellence and making a difference towards a more versatile TI99/4A for those without a full size TI-PEB. I am also making a case for this and other MPEB design footprints. The picture is my effort at my current 95% wiring. I hope you like my acronym calling it SAMSIDE and being a side car of SAMS + IDE, regards Arto