Upgrading (hot-rodding?) a Tandy 1000 EX with additional memory, storage, and CGA display?

[1200XL M.U.L.E.]

I had a very successful thrift store run this weekend. In addition to picking up an Apple IIc, I got a Tandy 1000 EX with an external 3.5" floppy drive. The 1000 EX fired right up and booted from the internal 5.25" drive. I also did a real quick test on the external 3.5" drive and it was able to read disks. This is very, very exciting! I really do like these wedge style machines and wish they'd make a comeback.

The machine has 256kB of RAM and I would like to expand this to 640kB and beyond. I did this with my IBM 5150 and my Epson Equity II using the Lo-Tech 1MB and 2MB EMS boards. It works quite well! Is there a similar solution available for the 1000 EX? I ask because I thought I read somewhere that the expansion bus is not ISA. Plus, I don't seem to have a riser card inside the machine.

Along those same lines, I would want to add a XT-IDE storage card too. I have one in my 5150 and Equity II.

Last question - I have an Epson RGBi (CGA) monitor that came with my Equity II. Will this monitor work with the 9-pin video output on the 1000 EX? I would think "yes" but wanted to ask the forum here before I go digging the monitor out from storage.

Thanks!

 

[mdh]

I’m pretty sure it has ISA slots, just not as long as ones for a PC. A max of 10.5 inches in depth vs 13 for IBM.

 

[Torch]

I bought a new EX in the late 80s and loved it, but eventually sold it after several years because Tandy never released a hard drive for it. I always regretted selling it and bought another about 6 months ago.

It does NOT have standard ISA slots. It's a proprietary connector and you only have one slot. If you buy the Plus RAM Expansion board you can bump it up to the full 640K with DMA. It also adds two more of the non standard slots.

Search Cybernetic Systems on Tindie. He sells inexpensive adapters to convert those non standard slots to ISA, which allows you to install small ISA boards.

The Radio Shack Plus Expansion board will be difficult to find. Someone recently had multiples they were selling on eBay and they were going surprisingly cheap (less than $90 I believe).

Option 2 is the Tandy 3in1 which you can usually find on eBay. It gives you full 640K, 96K upper memory, RS232 and XT-IDE. It doesn't have DMA and doesn't seem to allow additional expansion slots. It has pretty much everything you'll ever need, so the two extra slots are no big deal.

Mine had the Plus Expansion board, so I went with two of the ISA adapters. I installed a Blue Lava XT-IDE with a 2GB Verbatim CF card and a two port RS232 card with 9 pin and 25 pin ports. Also installed a V20 and bought a wifi modem for BBS use. It self boots to drive C: and 2,000 MB is more than most ever dreamed possible in 1988.

This is my setup...

 

[Eudimorphodon]

I built a board for both my "normal" 1000 EX and homemade zombie hack-computer based on the very similar 1000 HX's motherboard that adds two serial ports, 384K base + up to 128K of UMB, 1MB of EMS, a clock-calendar chip, and XT-CF-based storage on either CF or a laptop SD-PATA adapter, and has passthroughs for additional PLUS cards or ISA adapters like the original Plus RAM expansion. In the EX I use one of the passthroughs to run an ISA network card, while in the HX hack-puter I have network plus the other slot has a VGA card stuffed in it. (Blasphemy, I know, considering the main point of these things is the Tandy/PCjr graphics, but I mostly do non-game stuff with the machine and the VGA card is a significant quality of life upgrade for general DOS hackery.) Like the "3-in-1" my card doesn't have the DMA controller, but realistically about the only loss from not having it is rare compatibility issues with software that does low-level stuff with the floppy drive. (Copy protected software, mostly.) If you're running everything from XTIDE it's a nothingburger.

(Theoretically it's *possible* to stick a Soundblaster card or MFM hard disk controller into a 1000EX with an ISA adapter, DMA would be a must for those, but a Soundblaster in an XT is of kind of borderline usefulness under any circumstances. One plus of not having it is the machine runs about 5% faster.)

Anyway, there's usually someone churning out 3-in-1s, so if you're happy with what it gives you it's probably the path of least resistance. If you can't find either it *or* the original Tandy card I think the same guy that was selling the ISA adapters for the Tandy card also sold a multi-slot riser and with one of those it's *possible* to use the 1MB Lo-Tech card or equivalent to upgrade the RAM (you do have to use kind of weird switch settings, it's *not* the same as you would use for a 256K 5150), but it's probably the least optimal way to go.

 

[wmcbrine]

Yes, it should work with a standard CGA monitor. (The famous Tandy 1000 graphics were CGA hi-res with the full 16 colors, but the difference was on the computer end, not in the monitor.)

 

[1200XL M.U.L.E.]

@Torch and @Eudimorphodon ... Thanks for the replies!

Assuming I use an ISA riser card, would it be possible to use a Monotech XT-IDE Deluxe Card with the optional MicroRAM addon in one ISA slot and then use a 2MB EMS card from Lo-Tech in the other ISA slot?

Here is the Monotech XT-IDE Deluxe card.

XT-IDE Deluxe - Bootable ISA CF+IDE Interface Card

Note: Photos haven't been updated, but all new orders include an extra connector on the card, which can be used to plug a Monotech MicroRAM Rev1.1 card onto, saving an ISA slot in an 8088 machine. Note: This product can have some shipping delays if it is under heavy demand. Note: All orders...

monotech.fwscart.com

Here is the Monotech MicroRAM card. One of the product photos shows it installed in a XT-IDE Delux card.

MicroRAM - 640K + UMB RAM - 8-bit ISA

8-bit ISA card that fills any 8088 PC to the max, and then some! This updated version can be plugged onto Monotech XT-IDE Deluxe v1.1 cards, combining the two to save an ISA slot - useful for machines with a limited number of ISA slots such as IBM 5150. Supports machines with zero RAM. Supports...

monotech.fwscart.com

Does Tandy have any funky memory mapping that would prevent this Monotech combination with a Lo-Tech 2MB card?

There's a Canadian seller on eBay offering a 3-in-1 card.

Tandy 3in1 640k/96kUMB/RS232/Compact Flash card for 1000EX/1000HX | eBay

Find many great new & used options and get the best deals for Tandy 3in1 640k/96kUMB/RS232/Compact Flash card for 1000EX/1000HX at the best online prices at eBay! Free shipping for many products!

www.ebay.com

That card will take me to 1MB but I am still hoping to get to 2MB.

@Eudimorphodon Wow, you spun a custom board! Kudos to you! I used to spin board a long time in OrCAD for work so I appreciate your hard work.

Oh, and I did install an 8-bit VGA card and an 8-bit SoundBlaster card in my Equity II. In your video you said something like we do these things not because we have to but because we can (or something like that). I did this more to see if I can get away with it so to speak.

@wmcbrine Thanks for confirming compatibility! Looks like it should be worth the effort to pull out my CGA monitor.

 

[Eudimorphodon]

@Eudimorphodon Wow, you spun a custom board! Kudos to you! I used to spin board a long time in OrCAD for work so I appreciate your hard work.

Amusingly that board was the third generation prototype. I actually started the project to make "things" to expand my EX before there *were* any third-party solutions for doing it (the 3-in-1's memory decoding circuitry is based on experimentation in a thread I jumped into on this forum back in April 2019.) I just kept iterating because, well, it was a thing to learn new skills doing.

If you were feeling really ambitious I have a couple spare PCBs and some of the harder to find parts lying around, maybe I could be convinced to stuff them in an envelope sans any guarantee that the board will work in anyone else's computer. (It would probably take a *lot* of convincing to get me to solder a whole one together; it is all through-hole but it's a lot of holes.) You could build it without the onboard EMS mapper and use one of the passthroughs for a separate card if you really wanted 2MB instead of 1MB EMS. The board only has 1MB because of space limitations; in theory you could piggyback chips to get the full 2MB... there *might* even be enough spare I/O on the memory mapper GAL to do it without adding a decoder if you're using it in an EX and not doing the mad science HX memory map hacking I detailed in the video.

 

[Eudimorphodon]

Does Tandy have any funky memory mapping that would prevent this Monotech combination with a Lo-Tech 2MB card?

The EX (assuming you’re not putting a VGA card in it) has tons of open UMB space. Unlike the HX, which is… interesting.

For the base 640k backfill the trick you have to remember is that with a card like that Monotech you need to set the switches so RAM is enabled from 0-384k; the built-in RAM will *move up*. (I did a video about how/why this quirk exists in the Tandy 1000 series if you’re bored enough to want to listen to a dreary lecture starting with utterly arcane things IBM screwed up when they designed the IBM PCjr…)

The optimal way to mix EMS and UMB in the 1000EX is modify your EMS card to put the EMS frame at A000 and then put as much RAM as you can between C000 and EFFF.