Could someone educate me on options for HEPAX RAM size?

Discussion about the new DM41X calculator
Dave Britten
Posts: 129
Joined: Wed Jun 14, 2017 9:27 pm

Could someone educate me on options for HEPAX RAM size?

Post by Dave Britten »

I've got a Standard HEPAX 1D "plugged into" my 41X, and the module seems to have 4 ROM pages and 2 RAM pages (8 KB). The two RAM pages are occupying bank 1 of pages 8 and 9.

What are my options for increasing the amount of HEPAX RAM in the system? Can I fill the other three banks of pages 8 and 9? And can I do it without losing what's already stored in the HEPAX?
MeinKuipers
Posts: 34
Joined: Mon Jan 13, 2020 4:49 pm
Location: Netherlands

Re: Could someone educate me on options for HEPAX RAM size?

Post by MeinKuipers »

HEPAX supports up to 4 RAM pages, but these are not banked. So if you want 4 RAM pages (which appears to be the maxiumum for HEPAX) it would take pages 8, 9, A and B, although the page assignment is dynamic and depends on other modules in use.
In the DM41X the best option is to get a pre-cooked MOD file with 4 pages, as the RAM pages use a structure to link them together. You can actually play with the links yourself (WARNING: may invalidate all HEPAX RAM pages) and keep some RAM free for a simulated ROM page.

Recommended reading is the HEPAX manual, there is a good searchable copy available at hp41.org
Regards from NL,
Meindert Kuipers DM41X #48
Dave Britten
Posts: 129
Joined: Wed Jun 14, 2017 9:27 pm

Re: Could someone educate me on options for HEPAX RAM size?

Post by Dave Britten »

Okay, so a 16 K Advanced HEPAX with 4 pages would be the maximum RAM configuration? There's no way to stack all of that into 4 banks of the same page, is there? Where might one find a module that's been configured for 4 RAM pages? The one on hp41.org seems to be a 2-page 8 K version.
whuyse
Posts: 143
Joined: Thu Dec 21, 2017 1:23 pm

Re: Could someone educate me on options for HEPAX RAM size?

Post by whuyse »

Thanks for that question, Dave, to which I would like the answer as well.
While we're at it, what's the difference between the HEPAX-1D and the HEPAX-4H in Angel's module list? I've searched hither and thither but can't seem to find a description of the differences. All I find is the HEPAX-1G on hp41.org, but until I get a 41X there's no way to know if that is a 4K or 8K or even more. (I would like a 16K as well).
Cheers, Werner
42S #3249S01123
DM42 #00345
DM41X #01215
Ángel Martin
Posts: 128
Joined: Mon Apr 24, 2017 8:19 pm

Re: Could someone educate me on options for HEPAX RAM size?

Post by Ángel Martin »

Perhaps the attached helps...
Cheers,
ÁM
Attachments
HEPAX 4H Modifications.pdf
(79.91 KiB) Downloaded 63 times
Ángel Martin
Posts: 128
Joined: Mon Apr 24, 2017 8:19 pm

Re: Could someone educate me on options for HEPAX RAM size?

Post by Ángel Martin »

Dave Britten wrote:
Thu Feb 18, 2021 12:20 am
Okay, so a 16 K Advanced HEPAX with 4 pages would be the maximum RAM configuration? There's no way to stack all of that into 4 banks of the same page, is there? Where might one find a module that's been configured for 4 RAM pages? The one on hp41.org seems to be a 2-page 8 K version.
Not quite, you can configure as many HEPRAM pages as you want, of course with a maximum of 8 pages (or 32k) assuming your HEPAX ROM is tucked away in page 6 and no other ROMs are plugged.

The way to do this is by editing the HEPAX File Chain pointers. There is a function in the POWER_CL (HEPINI) that allows you to do this on the CL, but that's not possible on the DM-41X - because as Meindert has already mentioned pre-configured HEPAX MOD files need to be prepared..

You may read about this in the Power_CL Manual section covering the HEPAX support and utilities.The manual is available here: http://www.systemyde.com/pdf/POWERCL_EXT_P_Manual.pdf
On the CL the maximum number of HEPRAM pages is 7 (one less than the theoretical value) because the POWER_CL module already uses up one page.
whuyse
Posts: 143
Joined: Thu Dec 21, 2017 1:23 pm

Re: Could someone educate me on options for HEPAX RAM size?

Post by whuyse »

Thank you, Angel.
Does this mean HEPAX_4H needs the LIB4 module as well? It's not clear for me..
It isn't .. the very last line of your document, sorry!
Werner
42S #3249S01123
DM42 #00345
DM41X #01215
rprosperi
Posts: 1107
Joined: Mon Apr 24, 2017 7:48 pm
Location: New York

Re: Could someone educate me on options for HEPAX RAM size?

Post by rprosperi »

whuyse wrote:
Thu Feb 18, 2021 10:44 am
Thank you, Angel.
Does this mean HEPAX_4H needs the LIB4 module as well? It's not clear for me..
It isn't .. the very last line of your document, sorry!
Werner
I believe the intention of that last comment is that LIB4 is not needed for either the original or the 1G version, but I believe LIB4 IS required for the HEPAX_4H version; the "4" in the file name is a reminder of the dependency on LIB4. As a minimum, it would be required for the sub-function catalogs as described towards the top of the doc.
--bob p

DM42: β00071 & 00282, DM41X: β00071 & 00656, DM10L: 071/100
MeinKuipers
Posts: 34
Joined: Mon Jan 13, 2020 4:49 pm
Location: Netherlands

Re: Could someone educate me on options for HEPAX RAM size?

Post by MeinKuipers »

whuyse wrote:
Thu Feb 18, 2021 7:49 am
Thanks for that question, Dave, to which I would like the answer as well.
While we're at it, what's the difference between the HEPAX-1D and the HEPAX-4H in Angel's module list? I've searched hither and thither but can't seem to find a description of the differences. All I find is the HEPAX-1G on hp41.org, but until I get a 41X there's no way to know if that is a 4K or 8K or even more. (I would like a 16K as well).
Cheers, Werner
You can test on the excellent V41 emulator on your PC, no real hardware needed (except a Windows PC)
Regards from NL,
Meindert Kuipers DM41X #48
whuyse
Posts: 143
Joined: Thu Dec 21, 2017 1:23 pm

Re: Could someone educate me on options for HEPAX RAM size?

Post by whuyse »

No I can't. The only PC I have is a company-issued laptop on which I am not allowed and not able to install any *.exe except the ones in 'the list'. All I have on the side are iOS machines, and i41CX+, which is a possibility. But the DM41X is on its way ;-)
Werner
42S #3249S01123
DM42 #00345
DM41X #01215
Post Reply