TI99 Rarity Check

[halbert]

My dad recently bought a bunch of TI99 stuff from a guy in town, and a cart called "Diagnostic" was included in the pile. At a TI99 website, it is listed as Extremely Rare, although I kind of doubt the integrity of that list. As the DP guide doesn't have it, and there have been none on eBay that I could find -- What's the deal with this thing?

[sniperCCJVQ]

My dad recently bought a bunch of TI99 stuff from a guy in town, and a cart called "Diagnostic" was included in the pile. At a TI99 website, it is listed as Extremely Rare, although I kind of doubt the integrity of that list. As the DP guide doesn't have it, and there have been none on eBay that I could find -- What's the deal with this thing?

DP doesn't have this cart listed because is not a "game". But diagnostic cart are very rare.

[vintagegamecrazy]

nice finds nonetheless.

[halbert]

Thanks. I got your PM vintage, and I'll see what happens. It really belongs to my dad, not me, so I'll have to talk to him. What do these usually go for on eBay?

[vintagegamecrazy]

post or pm me a list and I can let you know. If nothing else I want that Diagnostic cart most of all.

Thanks

[halbert]

I understand, and the Diagnostic cart would be the only thing even potentially for sale or trade (everything else was purchased to be used), but first, I'd really like a couple opinions on the value. I don't know if it's $30 or $100, but I promise it's not going anywhere else in the meantime.

[vintagegamecrazy]

My honest guess would be in the 30 to 50 dollar range, but I could be wrong.

[digitalpress]

I received the following message from Bill Gaskill, a noted authority on the TI-99/4A and editor of our TI-99/4A section. Somehow I knew he'd have some insight here :)

"Thanks to Joe Santulli and Digital Press for giving me the opportunity to respond to this very interesting question.

The Texas Instruments Diagnostic cartridge PHM 3000 (MSRP of $29.95 when it was introduced) is not listed in the Digital Press Collector's Guide because it is a system utility cartridge, rather than being a game cartridge, retro games of course being the focus of the DPCG.

Diagnostic is one of 16 cartridge programs that were the first batch of cartridges produced for the original TI-99/4 in 1979. It was created to help repair technicians and users look at and check the performance of the keyboard, Random Access Memory, Video Display, sound tones and noise from the sound generator, calculations from the TMS 9900's arithmetic logic unit, the cassette recorder interface, the handset interface for testing the joysticks (what TI called the Wired Remote Controllers) and it offered a maintenance test designed for repair technicians that required a Signature Analyzer. Generally speaking, it was not a popular cartridge title in terms of sales, if for no other reason than its intended purpose. Kind of like buying a Chilton's Automotive Repair manual to go with your new car.

Because Texas Instruments never released sales figures of its Home Computer products, no one can concretely determine if a cartridge is "rare" based upon number of units sold. Thus the rarity scale for TI-99/4 and TI-99/4A cartridges has been, and remains, a largely subjective assessment, mostly based upon the individual owner's or collector's own experiences.

A year or so back I developed a Catalog Cartridge Scarcity Rating (CCSR) for TI-99 cartridges, based upon the assumption that a cartridge which appeared in retail dealer catalogs and price lists more often than another cartridge, would have more opportunities to be purchased, and thus should be more common today. While this is not a scientific assumption, it is the only effort that I am aware of to put some kind of quantifiable value to the term "rare" when it comes to TI-99 cartridges.

As a result of this effort, which included 69 TI-99 retail dealer catalogs and price lists from Texas Instruments and TI-99 retailers such as K-Mart, JC Penny, and the like, dating from 1980 to 1998, over 320 cartridge titles were categorized. The formula used yields a percentage that compares a specific cartridge title against all of the 'other' TI-99 cartridge titles found in the catalogs and price lists mentiond above.

TI's Diagnostic PHM 3000 cartridge rates as a .34% on the CCSR. To give you a frame of reference, the very common cartridges like TI Invaders and Parsec rate 7.42% and 6.75% respectively. The higher the rating, the more common the cartridge.

On the other end of the spectrum, the Asgard Extended BASIC III cartridge, released in 1992 has a CCS Rating of .03%, and John McKeown's 6000+ Module, which was marketed by Pilgrim's Pride and Tenex in the late 80's has a .02% CCS Rating. If you run across either, latch on to them.

Thanks again for the opportunity to respond to this interesting question. I hope the reply is of some help."

Bill Gaskill

[halbert]

Thanks for the info, DP. Strangely enough the guy did have something related to Extended Basic III if I remember correctly. I think it was only a manual...

vintage, I added you to my MSN list but have yet to see you online... Shoot me a PM.