Modules for the 71B - how?

[MattiMark]

Hi,
I am thinking of purchasing more memory to my (in my posession new) HP-71B. Can someone explain how to make use of a, let´s say, CMT 32k RAM-module? I see that there are 64k CMT RAM-modules as well, so can I (theoretically) use all 4 front bays with an additional 256k of RAM? I read somewhere ages ago that CMT had an 128 k RAM-module for the card-reader slot; what´s the maximum RAM I can have with this kind of HP unit?

Any help appreciated,
Regards Matti/Sweden

[Katie Wasserman]

(moved to General forum from Articles forum)

[anetzer]

Going for CMT modules means willing to pay rather steep prices per kb. I guess that at this time it might be a sensible idea to look at Hans Brueggemanns FRAM71.

See this thread:

http://www.hpmuseum.org/forum/thread-251...ght=fram71

and do further searches in the forum.

I do not know when and how many of these would be produced and what they would cost, but given the prices and the comparative performance, they might certainly be worth a PM to Hans...

a.

[rprosperi]

(02-08-2015 02:25 PM)MattiMark Wrote:  Hi,
I am thinking of purchasing more memory to my (in my posession new) HP-71B. Can someone explain how to make use of a, let´s say, CMT 32k RAM-module? I see that there are 64k CMT RAM-modules as well, so can I (theoretically) use all 4 front bays with an additional 256k of RAM? I read somewhere ages ago that CMT had an 128 k RAM-module for the card-reader slot; what´s the maximum RAM I can have with this kind of HP unit?

Any help appreciated,
Regards Matti/Sweden

As Anetzer replied, the best option by far is to acquire a FRAM71 when available, but to answer your specific questions:

Yes, you can insert 4 x 64KB modules to add 256KB (if you can afford it )

Each module can be used as system ram, for storing or running programs, however each port (whatever size module you use) can also be separated for storing files, like a small ram-disk.

There are card-reader slot memory modules in at least 64KB and 128KB, possibly even 256KB, but these are quite rare, and even more expensive.

You should look here, here, here, and here for some very useful LEX files, ROMs and peripherals to make you 71B much easier to use and manage and easily move programs and data between your 71B and PC.

[Marcus von Cube]

Here is an old article of mine on how to install the functions of a Math ROM in a RAM port:

http://www.hpmuseum.org/cgi-sys/cgiwrap/...i?read=908

[Sylvain Cote]

Like the other mentioned before, acquiring a FRAM71 is the best option.

But if you want use the original modules, here is the list of the ones that was produced by CMT & HHP

Code:

RAM/EPROM/OTP Front Port (FP) & Card Reader (CR) Modules
CMT FP RAM......:     CMT-71-[32R;64R]
CMT FP EPROM....:     CMT-71-[32E;64E]
CMT FP OTP......:     CMT-71-[32K;64K]-OTP
CMT CR RAM......:     CMT-CR-[32R;64R;128R]
HHP CR RAM......: HHP-71-M/M-[32K;64K;96K;128K;160K]
HHP CR EPROM....: HHP-71-M/M-[32E]
HHP CR RAM/EPROM: HHP-71-M/M-[32K/32E;64K/32E]

The 71B can address 512KB of memory (all types combined).

Available space: 512KB (max addressing) - 64KB (OS ROMs) - 16KB (HP-IL ROM) - 20KB (base RAM) = 412 KB available for modules

Sample config 1: 128 KB (CMT-CR-128R RAM) + 256 KB (4 * CMT-71-64R RAM) = 384 KB -> 28KB left
Sample config 2: 160 KB (HHP-71-M/M-160K RAM) + 192 KB (3 * CMT-71-64R RAM) + 32 KB (CMT-71-32R RAM) = 384 KB -> 28KB left
Sample config 3: 160 KB (HHP-71-M/M-160K RAM) + 192 KB (3 * CMT-71-64R RAM) + 32 KB (MATH ROM 32KB) = 384 KB -> 28KB left
...

[MattiMark]

Thanks all for the very valuable information!

Regards,
Matti/Sweden