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Model 4 with 128K badge...rarity or common?

A-ko

Experienced Member
Joined
Feb 14, 2017
Messages
168
Hi all, i've seen several photos of TRS-80 model 4s and I'm not sure i've seen another with the 128K badge that mine wears. Was this option only available as an upgrade, or were they available new with 128K of RAM? Possibly a stupid question, but my focus is not in the area of TRS-80s and i've often wondered if this was unusual or fairly common. Also, if it was available as upgrade-only, any idea what this upgrade would have cost through Radio Shack? Thanks!
 
I saw no 128K Model 4's, not even the Model 4D (last version). The last catalog I have showing the Model 4 has a 64K machine, and a $70 upgrade option.
 
I think you could get it that way, my model 4 is also a 128k version with 128k badge.
and lucky enough to have the highres card installed as well when I got it. :)

:)
 
Hi all, i've seen several photos of TRS-80 model 4s and I'm not sure i've seen another with the 128K badge that mine wears. Was this option only available as an upgrade, or were they available new with 128K of RAM? Possibly a stupid question, but my focus is not in the area of TRS-80s and i've often wondered if this was unusual or fairly common. Also, if it was available as upgrade-only, any idea what this upgrade would have cost through Radio Shack? Thanks!

I'd say they're fairly uncommon. I think you could get a new Model 4 with 128k RAM in the sense that if you asked for that, the store would install the upgrade before delivery, but your bill would have separate line items for the computer and the extra memory. The memory is catalog number 26-1122, which had the following price history:
Code:
 $149.00 1983 Fall   RSC-10   p. 27
  $79.95 1984 Spring RSC-11   p. 31
  $79.95 1984 Fall   RSC-12   p. 30
  $79.95 1985 Spring RSC-14   p. 29
  $69.95 1985 Fall   RSC-15   p. 33
  $69.95 1986 Spring RSC-16   p. 89
  $59.95 1986 Fall   RSC-17   p. 27
  $59.95 1987 Spring RSC-17B  p. 27
  $59.95 1987 Fall   RSC-19   p. 23
    ?    1988 Spring RSC-19B? (no known copy)
  $69.95 1988 Fall   RSC-20   p. 35
  $69.95 1989 Spring RSC-20A  p. 35
  $69.95 1989 Fall   RSC-21   p. 34
  $69.95 1990 Spring RSC-21A  p. 34
 
The 128K upgrade with badge was an uncommon dealer installed option, but not super rare.
 
In all of the Radio Shack Catalogs the Model 4 was not advertised with 128kB RAM. Even the most far ranging Model 4D was only available with 64k standard RAM according to the catalog. So I think it was an upgrade option.

The upgrade was sometimes documented with a 26-1122 64k RAM sticker on the bottom:

upgrade_sticker_s-l1600_06.jpg
upgrade_sticker_s-l1600_09.jpg

and sometimes there is no sticker:

no_sticker_s-l1600_01.jpg
no_sticker_s-l1600_08.jpg

(the photos are from 2016 Ebay auctions)
 
In my case, I went to one of the many computer centers in the Atlanta metro area, walked up to the counter, and said "I want a TRS-80 Model 4D with 128K." After reassuring them that, no, I really did not want one of the various Tandy 1000 systems, they quite literally walked to the back of the store and brought the box out to me. I paid them $799 plus tax, and took it back to my apartment. 128K from the factory. It never made the catalog, but I do think it was in one of the sales flyers. This would have been spring 1988. I may have the receipt here somewhere, since it was an insurance purchase to replace the one that I had stolen from me in January 1988.

It was on sale; I want to say it was at the North DeKalb Mall, and I believe the fellow who sold it to me was named Mike. Don't remember his last name, but it ended with either 'ski' or 'sky' but I can't seem to remember the first part of his last name. At least that's my recollection. The regular price was $1199.
 
Interesting! I guess as a second question, would these have had white or green monochrome screens from the factory? Mine has a green CRT but seems like a lot of the ones i've seen display white text. I need to do more with this machine!
 
Interesting! I guess as a second question, would these have had white or green monochrome screens from the factory? Mine has a green CRT but seems like a lot of the ones i've seen display white text. I need to do more with this machine!

Green screens started being used in the M4 around the time of the Gate Array architecture switchover. They are factory and were used exclusively once introduced. I'd say probably a little less than 1/2 the Model 4s out there are green screened.
 
That's because all export M4s got the green screen from the get-go. USA and Canada got the white screen until they ran out of them, which was roughly the time of the change from non-gate array to gate array. Since the M4s greatest sales success was the first two years after its introduction, its no wonder than on US and Canadian ebay most M4s are white screen.
 
Not sure on Model 4, but I bought a 4P in 1984 that was not a gate array but had the green screen. When did they switch to gate array?
 
My Model 4 has the 128k RAM badge. It's a model 26-1069A (64k, 2-drive, right?), serial number 0097279. There's an ink stamp on the bottom reading "AUG 28 1984". It has remnants of a service center tamper seal marked 11/23/84. Maybe that's when its RAM upgrade was installed? It's a gate array machine with a green screen. There's another ink stamp near the dataplate label which is too smudged for me to make out.

IMG_3620.jpg
 
Some more dating data:

According to the schematics in the service manual, the original PAL design for the Model 4 main logic board was "RELEASED FOR PRODUCTION" on 2/23/83, and the gate-array design was released 14 months later, on 4/10/84.

The first photo of a Model 4 in a dated Radio Shack periodical was on the cover of the May 1983 Microcomputer News, with a white screen and unclustered-arrows keyboard. Following the end of Microcomputer News in December, there were eight months with no Radio Shack periodical. Answers then started in September 1984, with the first issue showing a Model 4 with a green screen and clustered-arrows keyboard (p. 8).


Edit: Oops, as lafos says below, the last Microcomputer News wasn't until June 1984, and therefore we can narrow down the change in Model 4 stock photography to a three-month window. Thanks, lafos!
 
Last edited:
The last Microcomputer News was June 1984. It had photos inside of non-gate array Models 4 (p. 10) and 4P (p. 20) with unclustered arrow keys and what appear to be B&W screens. The photos are B&W so screen color is a guess.

The Tandy ad in January 1985 80 Micro shows a gate array Model 4.
 
I have a 128k badge and a relatively early Model 4 (Serial 000018, produced in France tough)



But the 26-1122 is the 64K extra memory kit done by Radio Shack which included the 128K badge:
 
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