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Spectrum I+ Stress Tester Unit

VGDB is proud to present, first time ever, a photo of the Stress Tester Unit


Roy Abel & Associates
Date  1984


A Luscher color test working on a b/w Vectrex based hardware by Roy Abel & Associates. 

These posts can be found from the newsgroup:

From: (Bruce Tomlin)
Subject: Stress Tester found! 
Date: 14 Sep 1996 09:34:31 -0700

Thanks to a lead from rgvc, I just brought home a Spectrum I "stress tester" Vectrex. And for only $50! The thing weighs a ton, because it has a pay-phone style base. I tried plugging it in and first got Mine Storm, then I got the words Spectrum I+, and the thing crashed. After that it would start up with garbage. I *hope* this is bad contacts, and not bit rot. This thing is riveted together, and I'll have to drill out the rivets or something like that to get it open to pull the EPROM and dump it.

FYI, the vertical post part is where the quarters collect. The barrel lock was missing, and when I untaped the coin bin, I found six quarters in there.

But I've got to go right now, so more on my find this evening.

From: (Bruce Tomlin) 
Subject: Re: Stress Tester found! 
Date: 14 Sep 1996 10:07:07 -0700

Of course you guys know me well enough by now to know that I would immediately try to open and dump the thing. Well I did. I still have to get out of here, but here's what I can tell you right now:

First of all, IT WORKS. Sure enough, it was just a bad connection. Other than that, the horizontal deflection shrinks momentarily every now and then.

The program is 32K ROM + 2K RAM. (Sorry Sean, looks like you'll have to develop that double-sided multi-cart board if you want to run this baby. :) Most of the 32K of ROM is ASCII text. It uses a board that is plugged in via an 18 inch cable to the cartridge slot, with a little stub board to actually go into the slot. The board contains all the RAM and ROM and switches, and is in itself a universal Vectrex EPROM board. They used four windowless 2764 chips to store the program on. The coin slot seems to be a simple optical interrupter, with no concerns for slugs, "soap on a rope", or whatever. They apparently took genuine Vectrex controllers apart just to scam their cables, TWO of them.

The principle of the thing is that you select 8 colors from a flower-shaped palette with the buttons inside it, in order of your most to least favorite. The buttons also have LEDs that go out as you choose colors. It then spits out a LOT of canned text to the screen. In fact, it doesn't use vectors at all, just text. They don't even have their own music, using only the canned music in the Vectrex Exec-ROM, but using it well. Also, the screen blanks when it's not running, and the LEDs flash in a spinning "attract mode" pattern.

From: PCJohn
Subject: Re: Stress Tester found! 
Date: Wed, 18 Sep 1996 01:45:40 GMT

Any idea what the RAM is used for ?
I popped it into the EPROM emulator and the thing ran fine.

(it uses) LOTS and LOTS of stock Vectrex music !

Basically, you can play the thing with 2 controllers (I had to keep switching the single controller between ports).

The words of the colors are displayed on screen. The top four colors are controlled by buttons 1-4 of controller 1 and the bottom four colors are controlled by buttons 1-4 of controller 2.

Lots of annoying scrolling too.

What's really scary, is that I have vague memories of seeing this thing when it first came out. Damned if I remember when or where.


From: (Bruce Tomlin) 
Subject: Re: Stress Tester found! 
Date: 19 Sep 1996 17:21:48 -0700 

>Any idea what the RAM is used for ?

Now that I've done a pretty thurough disassembly of it, I know a lot more. First, the RAM is primarily used to store advertising messages, but it also keeps config info and the count of coins that the machine has taken. It had a monster NiCd pack in it, and a couple of the leads had cold solder joints, so I replaced it with a more normal one. It also had silicone sealant stuff all over the damn place.

Also, the hardware problems with it seem to have been caused by a "more magic" wire. There was a wire with one end soldered to connect it to one terminal of the battery, and the other end loose, but with a little bit of heat shrink tubing on it. The other end was tapping against some circuit board holes that were intended to allow them to put in a jumper block to select a larger RAM chip, or maybe a fifth EPROM. The circuit board has 28 holes for the chip.) When it tapped against the circuit board, the LEDs stopped working, and it probably caused the deflection to flake out, too. It was really tough to track down why the LEDs worked when I flexed the circuit board!

According to 
"The guy that programmed it did not understand the hardware; the text scrolled up the screen, but lines popped on at the bottom and disappeared near the top instead of scrolling on and off from offscreen. Roy had GCE's permission and blessing to do the project. In fact, some former WT personnel (Sidleys and others) as well as Lee Chaden (big guy at GCE) were at Abel & Associates at the time."

More  Page about the binary and a download (click on the binary icon)
Thanks  Big thanks to Bruce Tomlin for the photo!

Price Range






Only one unit is known to have been found, that's why it is impossible to determine the price.


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