A ROM emulator for the 71B

[Sylvain Cote]

(01-17-2021 01:31 AM)mfleming Wrote:  One of the first rules of product development is to never, ever, let an Engineer write a user manual.
Those darn Engineers always tell you what they did rather than what you want to do. Hopefully this won't be quite that bad.

No worry, as long as you are there to answer our stupid and sometime no so stupid questions, everything will be fine.

(01-17-2021 01:31 AM)mfleming Wrote:  Sadly though, I can't provide a system takeover ROM capability due to the amount of time the ROM emulator takes to recover from deep sleep.

Bummer, so that mean that no diagnostic ROM support and no 1BBBB upgrade to 2CDCC will be possible.

Thank you Mark for your effort in making this product, it will be a great addition to the HP-71B system and a great contribution to our small community.

Now THE most important question, what will be the name of this product ?

I will take at least two units when available.

Sylvain

edit: typo

[Valentin Albillo]

  
Hi, Sylvain:

(01-17-2021 02:16 AM)Sylvain Cote Wrote:  Bummer, so that mean[...] no 1BBBB upgrade to 2CDCC will be possible.

For what is worth, I've always used the 1BBBB version for the past 35 years for all the sizeable amounts of BASIC code (and some Assembler) I've written for the HP-71B and never ever stumbled upon any problems or bugs.

Quote:Now THE most important question, what will be the name of this product ?

I'd suggest either FlemROM or AweROM   

Best regards.
V.

[Sylvain Cote]

(01-17-2021 02:39 AM)Valentin Albillo Wrote:  

(01-17-2021 02:16 AM)Sylvain Cote Wrote:  Bummer, so that mean[...] no 1BBBB upgrade to 2CDCC will be possible.

For what is worth, I've always used the 1BBBB version for the past 35 years for all the sizeable amounts of BASIC code (and some Assembler) I've written for the HP-71B and never ever stumbled upon any problems or bugs.

Yeah, my English language mastery is not great, bummer is a probably a too strong word here, it's just that Mark wrote that he plan to support it and in the end it is not, a minor deception at best for a great module.

(01-17-2021 02:39 AM)Valentin Albillo Wrote:  

(01-17-2021 02:16 AM)Sylvain Cote Wrote:  Now THE most important question, what will be the name of this product ?

I'd suggest either FlemROM or AweROM   

Other suggestions: Flash71, Mod71 or PM71 (Programmable Module for 71), lets start a naming contest! LOL

[mfleming]

My working name in my engineering notes has always been the MultiMod ROM Emulator since it can present Multiple Modules when plugged in. Dull, but serviceable.

Yeah, I'm really "bummed" myself about not doing a takeover ROM, but my idea of holding the HALT signal until the internal processor recovers was not treated kindly by J-F, and I strongly suspect it would cause scheduled alarms that wake the 71B to be lost. I'll play around with the idea later when time permits to see if it might actually work.

I'll provide more detail in a few days when the manual is posted. I can now really appreciate the amount of work Tony, Diego, J-F, and others went through to make a complex product available to others.

Maybe I just shudda kept my mouth shut, yeah?

[mfleming]

Hummm, I've reread this thread and noticed that most references to a takeover ROM concern the Diagnostic ROM rather than the OS ROM. So perhaps I should clarify things. It's perfectly possible to do a takeover ROM at address zero (assuming you have the shorting plug in Port 1), but not a persistent ROM (OS or otherwise) that would survive a power-down to sleep mode.

So the scenario in which you poke an enabling value, power off, insert the shorting plug, and then have a takeover ROM (e.g. Diagnostic ROM) running when you power back on seems to be feasible. If this sounds desirable, I can certainly add it to the task list. But, if you set the 71B aside for a while and power back on, the ROM won't be there. A quick on/off would bring it back unless you previously disabled it, which might not be want you want

Be careful what you wish for...

[Sylvain Cote]

(01-17-2021 03:51 AM)mfleming Wrote:  My working name in my engineering notes has always been the MultiMod ROM Emulator since it can present Multiple Modules when plugged in. Dull, but serviceable.

Contest closed! MultiMod it is.

(01-17-2021 03:51 AM)mfleming Wrote:  Yeah, I'm really "bummed" myself about not doing a takeover ROM, but my idea of holding the HALT signal until the internal processor recovers was not treated kindly by J-F, and I strongly suspect it would cause scheduled alarms that wake the 71B to be lost. I'll play around with the idea later when time permits to see if it might actually work.

No problem.

(01-17-2021 03:51 AM)mfleming Wrote:  I can now really appreciate the amount of work Tony, Diego, J-F, and others went through to make a complex product available to others.

I have been doing embedded product development and manufacturing development for years, I can attest that creating a prototype and creating a finished product is not the same thing.
Also, creating a product in a tiny production context (like here) or in a small volume productions context (20K units/month like I am used to), is also a different ball game.

(01-17-2021 03:51 AM)mfleming Wrote:  Maybe I just shudda kept my mouth shut, yeah?

True but hard.

[J-F Garnier]

(01-17-2021 01:31 AM)mfleming Wrote:  J-F, your Ultimate ROM has been realized! In addition to enumerating all of the above ROMs and hard ROM, the "hidden" ULIB52 ROM can be switched in and out as needed. Or any other 8K utility ROM you might want on tap - handy if you'd just like to copy a few LEX files to RAM without leaving the whole ROM set in your catalog & lex chain.

Great! But if all the ULIB52 is not constantly on-line, you can't claim it's THE Ultimate ROM :-).

(01-17-2021 03:51 AM)mfleming Wrote:  Yeah, I'm really "bummed" myself about not doing a takeover ROM, but my idea of holding the HALT signal until the internal processor recovers was not treated kindly by J-F, and I strongly suspect it would cause scheduled alarms that wake the 71B to be lost. I'll play around with the idea later when time permits to see if it might actually work.

Mark, if you are able to manage the mechanical aspects: creating a front port housing, building a connector and fitting the electronic inside, I'm sure we would be able to solve these little firmware problems together :-)

(01-17-2021 02:39 AM)Valentin Albillo Wrote:  For what is worth, I've always used the 1BBBB version for the past 35 years for all the sizeable amounts of BASIC code (and some Assembler) I've written for the HP-71B and never ever stumbled upon any problems or bugs.

As I did for many years, until I got a 2CDCC version a few years ago. I agree that most bugs are very specific and rarely happen (but when they do, there is a real risk of Memory Lost), except the DATE bug related to leap years that is quite annoying.

J-F