Old Skool HIRES

Turbo-Torch · November 20, 2018

Used to dream of catalog # 26-1125...the Model III High Resolution kit which Radio Shack introduced in 1982. Never actually viewed one in action; only catalog pictures with the $370 price tag. At the time my Model III was 16K cassette based and the hires kit required a 48K disk based system. The entire upgrade back in the day would have been close to $1,700 after required installation.

I've had an eBay search string set up for a few years and haven't been able to find one...they are quite rare.

Last week at Tandy Assembly I managed to pick one for $20 bucks! Jay wanted $50, I offered $40 and he agreed. When I paid, he gave me $20 back...very cool guy.

Installation is really goofy and I can see why Tandy wouldn't sell them without their techs installing it. It's actually a very large board mounted in a metal shield that replaces the original motherboard cover. A short 50 pin cable comes out the bottom which makes a tight turn and plugs into the outside 50 pin expansion port on the bottom of the computer. Then the cable continues a few inches outside computer and ends in a standard 50 pin female edge card connector with a male to male adapter so that you can still use an expansion peripheral such as a hard drive (or in my case a FreHD).

The computer's motherboard also needs a mod where you cut an IC pin and then solder a jumper lead to a ground on another IC.

After all that, you have to tweak the CRT video board to get a happy medium between new graphics mode and standard video mode.

The entire kit really seems like a homebrew type of creation but the end results are amazing for 1982.

My problem was I had no cable and had to make my own. Not a big deal until it came to the 50 pin male to male adapter. It has to reverse sides in order to keep the wiring configuration correct. After searching online for countless hours, they don't seem to exist. After digging through parts trying to get an idea, I noticed a Sega Master System Pro Wrestling cartridge...it has a 50 pin edge card with the correct pitch! Got out the dremel and did some soldering. Plugged FreHD into it and it gets along fine with the new graphics board. I'd like to find the real adapters so I can make a longer cable and daisy chain in a few more edge cards for more peripherals such as my Orchestra 90.

There's a site where you can put in a url of a picture and it'll give you a gload binary of it to download. It does a decent job. The board supports 640X240 and has 32K on board memory, so I think it could actually do better.

Last pic is the adapter...anyone know where I can buy something like that?