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Has someone a module of this?
10-22-2020, 02:32 PM (This post was last modified: 10-22-2020 02:32 PM by HP-Collection.)
Post: #1
Has someone a module of this?
I have three spare HP75 overlays of these, but no module / EPROM...
Does someone hast informations of this?
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10-22-2020, 03:20 PM (This post was last modified: 10-22-2020 03:28 PM by Dave Frederickson.)
Post: #2
RE: Has someone a module of this?
All I can find is a listing in the 1985 T&M Catalog.

HP-41, HP-71, and HP-75 Custom Keyboard Overlays
HP-41: HP 82501A
HP-71: HP 82487A
HP-75: HP 82721A

Relabel the HP-41, HP-71, or HP-75 keyboard with special userdefined functions assigned to each key. Available in a variety of background and printing colors.

... and this in the 1986 catalog.

HP-41, HP-71, and HP-75 Custom ROM Modules
HP-41: HP 82508A/B, HP 82509A/B
Provide 4K or 8K bytes of memory with each module, or nearly 21,000 program lines with up to four 8K byte modules.
HP-71: HP 82491A/B, HP 82492A/B, HP 82493A/B, HP 82494A/B
Provide 16K, 32K, 48K, or 64K bytes of program storage in a plugin module. May be used in quantities of one to four for a maximum
capacity of 256K ROM. (Minimum order: 100 modules.)
HP-75: HP 82726A/B, HP 82727 A/B, HP 82728A/B,
HP 82729A/B
Provide 8K, 16K, 24K, or 32K bytes of program storage in a plugin module. May be used in quantities of one to three for a maximum
capacity of 96K ROM. (Minimum order: 100 modules.)

So, there were at least 100 modules out there somewhere.

You might try giving the folks over at https://groups.io/g/hp75 a ring.
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10-23-2020, 04:23 AM
Post: #3
RE: Has someone a module of this?
There is a 75C for sale on eBay with this overlay, but if it has a module there is nothing printed on the outside. You could contact the seller to see if he can pull all the modules to verify if they are all blanks or not.

It is possible that this was just software on a disk though and not module based.
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10-23-2020, 12:32 PM
Post: #4
RE: Has someone a module of this?
(10-23-2020 04:23 AM)Ken S Wrote:  There is a 75C for sale on eBay with this overlay, but if it has a module there is nothing printed on the outside. You could contact the seller to see if he can pull all the modules to verify if they are all blanks or not.

It is possible that this was just software on a disk though and not module based.

FYI - It's been listed for a long time, there is no module included, seller knows nothing about it.

--Bob Prosperi
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12-27-2020, 08:22 PM
Post: #5
RE: Has someone a module of this?
I was looking through the photos section on the HPCC2020 Thumb drive and ran across this in the HP Slides Section:

   

Perhaps this was an HP internal application for their service people?

I did buy an HP-75 on eBay with that overlay. No ROM was included but the 75 is working great.

My Collection: 55, 67 (Teenix Mod), 15C, 16C, 41CV, 41CX, 41-CL, DM41X, DM42, 42S, 48G, 71B, 75C, 95LX, HP-150, Portable+, HP-86, Integral PC.
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