PG Designs M100 RAM Expansion

Intro

PG Designs made several ram expansion boards for Model 100 that ranged from 32K to 224K.
These devices added extra ram to a Model 100 in the form of 32K "banks", where each bank was essentially a whole separate computer. You use the extra ram by switching from one bank to another, and while in one bank you generally only have access to the files in that bank. It's almost as if you put one Model 100 away and pulled out a different one. The PG Designs ram adds to the original ram inside the Model 100, so if you have 32K installed in the Model 100, and add the the 224K PG Designs, you have a total of 256K available, in the form of 8 banks, where bank 1 is the original internal ram, and banks 2-8 are provided by the expansion.

• 
• 
• 
• 

Files

File:PG Design Expansion RAM for TRS-80 Model 100 - 1984 32k.pdf

File:PG Design Expansion RAM for TRS-80 Model 100 - 1985 64k.pdf

File:PG Design 0MENU 2.01.zip

Installing the bank-switch utility

Back up any files you care about currently on the M100.

Hard reset the M100 (wipe the ram): CTRL+BREAK+RESET

Use a TPDD client (like TS-DOS) and a TPDD server (like dl2 or laddie) to copy MENU.BA to the Model 100.

(You can't convert this to ascii basic and transfer it via TELCOM like you could any other BASIC program. It must be treated like a binary and copied only via some binary-safe method. This could be cassette or xmodem etc, but TPDD is the most convenient.)

example $ dl -v -b TEENY.100 && dl -v -u

Then on the 100 use TEENY to copy MENU.BA

The command in TEENY would be L MENU .BA

Run MENU.BA

Answer the prompts about which bank you are currently in and how many banks your unit has.

After the power-cycle, you are in bank 1.

If your unit has 7 ram chips (3 are hidden in between the two pcbs), that is 8 banks, the Model 100's original 32k plus 7 more banks of 32k.

Ignore the “FC error in 4” error that flashes by. It's not really an error in this case.

At this point the program is installed, though you can't see it.
It is an invisible program called 0MENU. (number zero, not letter oh)

To run it, type 0MENU at the main menu and press Enter.

You should now see a new modified main menu, and you can switch to another bank.

Once you switch to some other bank, it will be a new empty bank that doesn't have 0MENU or anything else in it.

To get back to bank 1 or any other bank, you can repeat the 0MENU install in the new bank, and all other banks.
With 0MENU installed in all banks, then you can switch directly from any bank to any other.

You can also just power-cycle the machine and that will always put you back to bank 1.
Since bank 1 has 0MENU installed, and you can always get to bank 1 by power-cycle, you could get by with only the bank 1 install.

Usage

0MENU also allows you to copy files from any bank that has 0MENU to any other bank that has 0MENU.

You can use INVISO.BA to make the program visible (MENU.BA), or invisible again (0MENU).

TODO

Create an mp3 cassette version of MENU.BA.

Create a 0MENU loader that can be bootstrapped directly like teeny/ts-dos/etc?

Credits / References

Thanks to Stephen Adolph for documenting the install and usage procedures and providing a pdf scan of the manual to an early 32k (single bank) model.

Pictures: https://photos.app.goo.gl/HgBp1QsyNhM4JUg78

M100SIG.ZIP: https://archive.org/details/M100SIG

There are several bits of info about the PG Designs ram expansion all through different places in this archive. Here are some examples, but look through the whole thing yourself:

Lib-09-PERIFERALS/BANKSW.100

Lib-09-PERIFERALS/PG-TIP.000

Lib-09-PERIFERALS/PG-TIP.001

Lib-09-PERIFERALS/PG-TIP.002

Lib-09-PERIFERALS/PG64K.DVI

Lib-09-PERIFERALS/PGMENU.100

Lib-09-PERIFERALS/PGMUNK.TIP

Lib-09-PERIFERALS/RAMEXP.THD

Lib-09-PERIFERALS/DSKMGR.PGD

LIB-13-REVIEWS/BIGRAM.THD

LIB-13-REVIEWS/BIGRAM.REV

LIB-13-REVIEWS/PGD64K.REV

http://www.tmne.com/downloads.html (see floppyco.txt from the menu_ba.zip here)

http://www.club100.org/memfiles/index.php?direction=0&order=&directory=Steve%20Adolph/MENU%20add%20on%20for%20M100%20and%20T102& 0menu v1.3

https://drive.google.com/drive/folders/0Bys6eLbSbYyhZTY1a3VXVFRUQmM?resourcekey=0-DIPxlRnOkDgk9HVRscvFEw 0menu v2.01 (from Richard Hanson below)

http://www.club100.org/library/libups.html See the RICHARD HANSON section

PG Design Data Transfer Utility v2.01 for 32K - 224K RAM Expansion units.

Please note: The MENU.BA file is not in ASCII due to embeded machine language code. You must download with xmodem or greater. The INVISO.BA file is ASCII.

MENU.BA

INVISO.BA

Apparently these were also sold under the name Enterprise Systems? Maybe re-seller? https://drive.google.com/file/d/1pJcSvFAw4smcPIzbVWhnBLERoaKb3xqX/view

Compatibility issue, and work-around, with the stock Tandy dos for TPDD and TPDD-2: http://www.ordersomewherechaos.com/rosso/fetish/m102/web100/docs/pdd2-dos-patch.html