HP-75 Designations?

[toml_12953]

I see ads for HP-75 C and D. Are there only those two? What are the differences? Which is the most powerful of the HP-75 line or isn't there a difference in that regard?

[Steve Simpkin]

(12-28-2020 02:27 AM)toml_12953 Wrote:  I see ads for HP-75 C and D. Are there only those two? What are the differences? Which is the most powerful of the HP-75 line or isn't there a difference in that regard?

From the HP Museum page for the HP-75C/D.
"The HP-75D added a wand and wand port." The HP-75C was introduced in 1982. The HP-75D came out in 1984. I don't know if there were any other differences other than the price.

[Sylvain Cote]

The only difference between the HP-75C and the HP-75D is the wand port.

HP also introduced the Bar Code module and two wand version for the HP-75D.
Later on, HP introduced the POD who had some of the bar code module logic.
HP-75D inventory system often had: HP-75D in the POD with a wand.

Code:

Model            Description                           Introduction USD Price : Year
75C              Handheld Computer   (16KB RAM, HP-IL, Card Reader)   $995.00 : 1982
75D              Handheld Computer   (75C + Wand Port)               $1095.00 : 1984
82700A           8KB RAM Module                                       $195.00 : 1983
82725A           Bar Code Module     (75D only)                        $75.00 : 1984
92267A           Hi-Resolution Wand  (75D only)                       $160.00 : 1984
92267B           Med-Resolution Wand (75D only)                       $150.00 : 1984
82718A opt. 032  Expansion Pod       (300 Baud Modem + 32KB E.Disk)   $875.00 : 1984
82718A opt. 064  Expansion Pod       (300 Baud Modem + 64KB E.Disk)  $1175.00 : 1984

[J-F Garnier]

(12-28-2020 02:27 AM)toml_12953 Wrote:  I see ads for HP-75 C and D. Are there only those two? What are the differences? Which is the most powerful of the HP-75 line or isn't there a difference in that regard?

More important than the 75C/D labelling is the ROM version.
The ROM version can be obtained with VER$ but is rarely mentioned in ads.
There are basically 4 versions: aaaaaa , bbbbbb , cccccc , dddddd.
although it existed some mixed versions like bababa.
The latest version dddddd is preferable.

Moreover, there is no simple correspondence between the 75C/D variants and the ROM versions, there are examples of 75D with ROM aaaaaa or bbbbbb although you have better chance to find the dddddd ROM in a 75D.

J-F