Binary Dinosaurs Computer Museum
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EACA EG3200 Genie III
Back in April 2021 fellow collector Andy Collins (RandomOrbit) was having a clearout of long term projects and asked me if I'd like his Genie III. I couldn't jump in the car fast enough.
The Genie III was released in 1982 along with the Color Genie, and they both had exactly the same effect on the market, ie none. They sold around 12 (sarcasm) which is why they're rare today. This machine is huge, 56cm square when fully put together which is roughly the size of an Intertec Superbrain from 1979. It even uses the same floppy drives as a Superbrain QD, the Tandon TM100.
A shame really, because not only was it a dedicated NEWDOS/80 machine and compatible with the TRS80 Model 1, it was also compatible with EACA's own Genie I and Genie II (themselves TRS80 Model 1 clones) but also ran CP/M 2.2 and CPM 3.0. Flexible machine with fully customized display and separate keyboard, it could do 64 or 80 chars natively and supported single and double density floppies out of the box. The keyboard itself had 16 programmable keys and used the same switches as the Genie I so it was a really comfortable keyboard to use. Price? £1395 to you, chief.
This machine currently doesn't have a video subsystem or CRT, for the pictures I used a (you guessed it) Superbrain CRT. What's mysterious about it is that the stock Genie III has a single 2532 ROM which contains very useful diagnostic routines and the boot code. This machine has 4 ROMs present in its 3 slots with the primary 2 being driven via a pair of switches under the floppy drives. Some lovely spaghetti and jumper mangling is necessary to select these EPROMs so initially I've removed the mods and used a copy of a standard Genie III boot ROM to return it back to factory. Thanks to Belgian Genie III owner Kris for the ROM dump. The other ROMs appear to be GENIE III BASIC, two flavours of, meaning that a floppy disk isn't necessary to boot into something useful.
With the stock ROM in place I discovered the 74LS244 driver chip that powers A0-A7 to the rest of the machine was dead, and also one of the backplane slots had a short on the pins joining A6 and A7 together. All sorted now and the machine does try and boot, but without video and what looks like a bad 1791 floppy controller I'm not going to get much further. The scope pics show the video trying to do what it knows best.
The other thing I had to sort was the PSU. The stock Genie III has a unit which will deliver +5V/+12/-15V, and the -15 is further split into -5V and -12V via a pair of TIP30 transistors, a resistor divider network and a pair of diodes. I removed all of that and fed -5V/-12V directly from the ASTEC PSU I'd bought for another project years ago. Works nicely. Just need to find a video board/CRT combo now.
Pictures

All images and text © Adrian Graham 1999-2024 unless otherwise noted using words. Also on