Question on '71B Hardware Interfaces

[mcquiggi]

Hi All:

I'm a newbie. I acquired a '71B a couple of weeks ago, as I liked the look of the machine. Really cool! My background is in "Jurassic" computing science so I liked the idea of the '71B as a BASIC device.

I've been reading the forums and corresponding with some members - what a great resource and a knowledgeable group of people here!

I have historical experience with HP calculators, from my school days and a through my work, but most of my HP experience has been with their test equipment - signal generators, spectrum analyzers, and the like.

My post here concerns the hardware interfaces on the '71B - the ports that accept RAM, ROM, etc. Are there specifications available for these? I am interested in (potentially) building my own device that can add functionality/memory/? to the '71B through connection to these ports.

In the least, I see 4K RAM modules on eBay for $32: while I value "stock" parts, I am sure that it must be possible to build one's own RAM module for far less than $32, if the specs/schematics are available.

I've seen the Pil-Box, that is neat, but it is more of a network-side interface.

Perhaps these port-side devices exist already and I haven't found them yet. I've seen the FRAM device but my own '71B has a card reader so that port is taken! I'd like to leave the card reader in place.

Anyway, my apologies if this an RTFM question, but on a bit of a search I couldn't find anything quite relevant.

Kevin

[Sylvain Cote]

Hello Kevin,

Dave Hicks is selling the Museum Document Sets (Version 8.0) ($38.00 USD) which includes the following 71B internal documentation:

• HP-71B Forth Assembler IMS/IDS (528 pages)
• HP-71B HP-IL Internal Design Spec Vol 1 (194 pages)
• HP-71B HP-IL Internal Design Spec Vol 2 (756 pages)
• HP-71B Hardware Internal Design Specification Vol 1 (28 pages)
• HP-71B Hardware Internal Design Specification Vol 2 (102 pages)
• HP-71B Hardware Internal Design Specification Vol 3 (23 pages)
• HP-71B Hardware Internal Design Specification (more complete, 164 pages)
• HP-71B Internal Design Spec Vol 1 (570 pages)
• HP-71B Internal Design Spec Vol 2 (858 pages)
• HP-71B Internal Design Spec Vol 3 (3132 pages)
  

Sylvain

[mcquiggi]

(06-17-2018 06:11 PM)Sylvain Cote Wrote:  Hello Kevin,

Dave Hicks is selling the Museum Document Sets (Version 8.0) ($38.00 USD) which includes the following 71B internal documentation:

• HP-71B Forth Assembler IMS/IDS (528 pages)
• HP-71B HP-IL Internal Design Spec Vol 1 (194 pages)
• HP-71B HP-IL Internal Design Spec Vol 2 (756 pages)
• HP-71B Hardware Internal Design Specification Vol 1 (28 pages)
• HP-71B Hardware Internal Design Specification Vol 2 (102 pages)
• HP-71B Hardware Internal Design Specification Vol 3 (23 pages)
• HP-71B Hardware Internal Design Specification (more complete, 164 pages)
• HP-71B Internal Design Spec Vol 1 (570 pages)
• HP-71B Internal Design Spec Vol 2 (858 pages)
• HP-71B Internal Design Spec Vol 3 (3132 pages)
  

Sylvain

Wow, fantastic document set and reasonable cost!

Thank you very much!

Has anyone designed custom modules for the RAM/ROM front ports? If so, what functionality did they include?

Kevin

[mcquiggi]

(06-17-2018 06:11 PM)Sylvain Cote Wrote:  Hello Kevin,

Dave Hicks is selling the Museum Document Sets (Version 8.0) ($38.00 USD) which includes the following 71B internal documentation:

• HP-71B Forth Assembler IMS/IDS (528 pages)
• HP-71B HP-IL Internal Design Spec Vol 1 (194 pages)
• HP-71B HP-IL Internal Design Spec Vol 2 (756 pages)
• HP-71B Hardware Internal Design Specification Vol 1 (28 pages)
• HP-71B Hardware Internal Design Specification Vol 2 (102 pages)
• HP-71B Hardware Internal Design Specification Vol 3 (23 pages)
• HP-71B Hardware Internal Design Specification (more complete, 164 pages)
• HP-71B Internal Design Spec Vol 1 (570 pages)
• HP-71B Internal Design Spec Vol 2 (858 pages)
• HP-71B Internal Design Spec Vol 3 (3132 pages)
  

Sylvain

I just ordered the document set!

Kevin

[Sylvain Cote]

(06-17-2018 06:18 PM)mcquiggi Wrote:  Thank you very much!

You're welcome

(06-17-2018 06:18 PM)mcquiggi Wrote:  Has anyone designed custom modules for the RAM/ROM front ports? If so, what functionality did they include?

You bet!

The holy grail module for the HP-71B is the FRAM71 & FRAM71B created by Hans Brueggemann.
One member is currently selling his module, see here: For Sale: FRAM71 512KB New in Box

Look at the HP-71B Compendium for more information and web site links.

Sylvain

[mcquiggi]

(06-17-2018 06:58 PM)Sylvain Cote Wrote:  

(06-17-2018 06:18 PM)mcquiggi Wrote:  Thank you very much!

You're welcome

(06-17-2018 06:18 PM)mcquiggi Wrote:  Has anyone designed custom modules for the RAM/ROM front ports? If so, what functionality did they include?

You bet!

The holy grail module for the HP-71B is the FRAM71 & FRAM71B created by Hans Brueggemann.
One member is currently selling his module, see here: For Sale: FRAM71 512KB New in Box

Look at the HP-71B Compendium for more information and web site links.

Sylvain

Thank you!

Kevin

[rprosperi]

I agree completely with Sylvain... the Card Reader is cute, but a FRAM Module gives you the ultimate possible utility for any kind of RAM/ROM device that could work in this machine. Get it while you can. I believe this is only the 2nd FRAM module ever sold after the initial limited lots were purchased.

As well, the PIL-Box is as must-have as a FRAM module, and in some ways even more useful, as it provides easy, quick and reliable access to hundreds of disk/tape images full of files including BASIC programs, LEX files, Forth files, Technical notes, assembler source files, etc. There is literally more available than you could ever check out in a lifetime.

In addition to virtual media, it also can provide virtual devices for Display, a Printer, and even remote terminal use (use you PC screen and keyboard to operate your 71b).

If you have to prioritize, I'd say the PIL-Box gives you more all-around exploration and usability options, while the FRAM module provides 512KB of RAM or emulated ROM, enough to fill the 71B address space (and let you install ROM images for all the HP and 3rd party application ROMs).

Best case, get both.

[mcquiggi]

(06-17-2018 11:03 PM)rprosperi Wrote:  I agree completely with Sylvain... the Card Reader is cute, but a FRAM Module gives you the ultimate possible utility for any kind of RAM/ROM device that could work in this machine. Get it while you can. I believe this is only the 2nd FRAM module ever sold after the initial limited lots were purchased.

As well, the PIL-Box is as must-have as a FRAM module, and in some ways even more useful, as it provides easy, quick and reliable access to hundreds of disk/tape images full of files including BASIC programs, LEX files, Forth files, Technical notes, assembler source files, etc. There is literally more available than you could ever check out in a lifetime.

In addition to virtual media, it also can provide virtual devices for Display, a Printer, and even remote terminal use (use you PC screen and keyboard to operate your 71b).

If you have to prioritize, I'd say the PIL-Box gives you more all-around exploration and usability options, while the FRAM module provides 512KB of RAM or emulated ROM, enough to fill the 71B address space (and let you install ROM images for all the HP and 3rd party application ROMs).

Best case, get both.

Thanks Bob, sounds like good advice. PIL-Box sounds essential.

Kevin

[Garth Wilson]

(06-17-2018 06:02 PM)mcquiggi Wrote:  but most of my HP experience has been with their test equipment - signal generators, spectrum analyzers, and the like.

That's where I got my start, first with the 41cx and then with the 71, using the HP82169A HPIL-to-HPIB (IEEE4888) interface converter, the FSI164A for RS-232, and the HP82165A for parallel.

Quote:In the least, I see 4K RAM modules on eBay for $32: while I value "stock" parts

I have a 64KB front-port RAM module from CMT, but I've never seen one on eBay. I also have a 96KB from them for the card-reader port, and they also had 128KB and 160KB but I didn't have the budget for those. These all had lithium backup batteries so you could remove them (assuming they're FREEPORTed) without losing data.

[rprosperi]

(06-17-2018 11:36 PM)Garth Wilson Wrote:  I have a 64KB front-port RAM module from CMT, but I've never seen one on eBay. I also have a 96KB from them for the card-reader port, and they also had 128KB and 160KB but I didn't have the budget for those. These all had lithium backup batteries so you could remove them (assuming they're FREEPORTed) without losing data.

All front port modules (4K from HP, 32K, 64K from CMT) as well as Card Reader RAM modules (96K, 128K and 160K from CMT and 32K, 64K, 96K RAM, and 32K RAM/32K EPROM from HHP) have been sold on eBay in the last few years (sometimes bundled with a 71B), but they are all quite-to-very expensive - a lowly 32KB front port RAM module goes for anywhere between $100-200, usually towards the high end. Although this is still far cheaper than they were back in the day (e.g. 32K was $395), it's still high for hobby accessories!

Garth - Do you have any idea where to get replacement Lithium batteries that fit the CMT front port 64K module?

[Dave Frederickson]

(06-18-2018 12:20 AM)rprosperi Wrote:  Garth - Do you have any idea where to get replacement Lithium batteries that fit the CMT front port 64K module?

Ah, the $64k question.

[Garth Wilson]

(06-18-2018 12:20 AM)rprosperi Wrote:  

(06-17-2018 11:36 PM)Garth Wilson Wrote:  I have a 64KB front-port RAM module from CMT, but I've never seen one on eBay. I also have a 96KB from them for the card-reader port, and they also had 128KB and 160KB but I didn't have the budget for those. These all had lithium backup batteries so you could remove them (assuming they're FREEPORTed) without losing data.

All front port modules (4K from HP, 32K, 64K from CMT) as well as Card Reader RAM modules (96K, 128K and 160K from CMT and 32K, 64K, 96K RAM, and 32K RAM/32K EPROM from HHP) have been sold on eBay in the last few years (sometimes bundled with a 71B), but they are all quite-to-very expensive - a lowly 32KB front port RAM module goes for anywhere between $100-200, usually towards the high end. Although this is still far cheaper than they were back in the day (e.g. 32K was $395), it's still high for hobby accessories!

Garth - Do you have any idea where to get replacement Lithium batteries that fit the CMT front port 64K module?

I didn't pay that much, but I could probably only dream of getting one in the early production time until SRAM prices came down from the original prices.

I don't have any idea where to get that thin postage-stamp-like battery for the front port RAM. I might have taken mine out a few years ago just to make sure it wouldn't leak in the computer, after it was nearly 30 years old but was apparently not dead yet. I think I put heat-shrink tubing over the one in the card reader port RAM module. I don't remember. I have no real interest in removing and reinstalling, so keeping the memory when they're out of the computer is irrelevant.