(41CL) Advantage Pac (41AD) mapped to page 2?

[cdmackay]

[I hope this is an OK place to ask 41CL questions? If there's a more appropriate forum, or list, please tell me off and I'll take it there]

I've just (yesterday) got my 41CL, and am having some initial plays with it. What a great piece of kit

I was looking around at what was mapped on the MMU, and was surprised to find the Advantage Pac (ROM image 41AD) apparently mapped to page 2. That's really page 2, not port 2 (pages 10 & 11).

To verify that, I thought I would reset the MMU and start from scratch.

I did a backspace-ON, verified the MMU was disabled, then did MMUCLR.

I then loaded YFNX (41CL Extreme Functions) to page 6 with PLUGP (having read that this ROM is safe there). Then enabled the MMU.

I then used the YFNX function PLUG to search the mapped modules, with "?IMG ?", which produced:

Code:

41AD 2
YFNX 6

Just to check that, I read the value at RAM physical address 0x80402C, which is the MMU entry for page 2, set 0:

Code:

ALPHA 80402C-0000 ALPHA
YPEEK

which returned 0x800C. The 0x8000 is the MMU Enable bit, and 0x00C is indeed the page for the 41AD module.


Is this expected? I thought pages 0–2 were for the OS itself, and weren't mapped by the MMU? So why does there appear to be a ROM image mapped at page 2?

Most likely I have deeply confused myself, in which case apologies, but would someone please straighten me out? thanks!

[rprosperi]

(02-26-2019 07:57 PM)cdmackay Wrote:  ...
Is this expected? I thought pages 0–2 were for the OS itself, and weren't mapped by the MMU? So why does there appear to be a ROM image mapped at page 2?

Most likely I have deeply confused myself, in which case apologies, but would someone please straighten me out? thanks!

You can safely ignore this, assuming the machine is running right. I believe the 41AD in 0x80402C is just coincidentally the same as the code for the Advantage ROM. The OS pages are handled uniquely by the MMU; for example MMUCLR does not initialize the 400C-403C blocks at all.

But may I observe you're really making rapid progress learning your new CL, these issues and spelunking this deep is not typical in my experience for day-1!

Assuming your flash is fully updated, install Angel's Library-4 (4LIB) and AMC/OSX (OSX3) right away, and you'll probably never look back. They are such a basic part of CL life for me, that when I use a 41 without them, I get confused and think something is not working right.

[cdmackay]

(02-26-2019 11:49 PM)rprosperi Wrote:  You can safely ignore this, assuming the machine is running right. I believe the 41AD in 0x80402C is just coincidentally the same as the code for the Advantage ROM. The OS pages are handled uniquely by the MMU; for example MMUCLR does not initialize the 400C-403C blocks at all.

But may I observe you're really making rapid progress learning your new CL, these issues and spelunking this deep is not typical in my experience for day-1!

Assuming your flash is fully updated, install Angel's Library-4 (4LIB) and AMC/OSX (OSX3) right away, and you'll probably never look back. They are such a basic part of CL life for me, that when I use a 41 without them, I get confused and think something is not working right.

thanks very much indeed, Bob. I wondered about it being just coincidental, but bit 15 being set and then just 0xc seemed a bit too coincidental

I've yet to try the serial connection, so my Flash/IMG databases are only current to December, but I will get those updated in the next few days, and so pickup a few module updates that I've seen.

I had 4LIB and Angel's PowerCL Extreme installed, which looks amazing although I only had a chance to scratch the surface. I'll have a look at OSX3, thanks.

Any other "must have" ROMs, for general utility use? Other than the 16C emulator which I am looking forward to trying

thanks again.

[Monte Dalrymple]

(02-26-2019 07:57 PM)cdmackay Wrote:  [I hope this is an OK place to ask 41CL questions? If there's a more appropriate forum, or list, please tell me off and I'll take it there]

I've just (yesterday) got my 41CL, and am having some initial plays with it. What a great piece of kit

I was looking around at what was mapped on the MMU, and was surprised to find the Advantage Pac (ROM image 41AD) apparently mapped to page 2. That's really page 2, not port 2 (pages 10 & 11).

To verify that, I thought I would reset the MMU and start from scratch.

I did a backspace-ON, verified the MMU was disabled, then did MMUCLR.

I then loaded YFNX (41CL Extreme Functions) to page 6 with PLUGP (having read that this ROM is safe there). Then enabled the MMU.

I then used the YFNX function PLUG to search the mapped modules, with "?IMG ?", which produced:

Code:

41AD 2
YFNX 6

Just to check that, I read the value at RAM physical address 0x80402C, which is the MMU entry for page 2, set 0:

Code:

ALPHA 80402C-0000 ALPHA
YPEEK

which returned 0x800C. The 0x8000 is the MMU Enable bit, and 0x00C is indeed the page for the 41AD module.


Is this expected? I thought pages 0–2 were for the OS itself, and weren't mapped by the MMU? So why does there appear to be a ROM image mapped at page 2?

Most likely I have deeply confused myself, in which case apologies, but would someone please straighten me out? thanks!

Robert is correct. MMUCLR and MMUCLP do not affect the MMU locations for pages 0-3. But that's okay, because these pages are never enabled unless you enable the special MMU mapping for the OS pages. Being located in RAM, the MMU registers can power up holding anything, and that's why you must do MMUCLR before enabling the MMU. In a similar fashion, you must initialize the MMU registers for the OS pages before you issue the MAPEN command.

I deliberately did not initialize the MMU pages for the OS sector with MMUCLR, thinking that if someone was actually using the MAPEN feature to run their own OS code they wouldn't appreciate having to reinitialize the MMU registers for the custom OS all the time. But I don't think anyone besides me has used the CL with their own OS. I have only done it when I am playing around with experimental patches.

If the random stuff in those MMU locations bothers you (like when you do a PLUG ?IMG ? command to see the MMU contents) just do PLUG EMPT x, where x is 0-3 to clear those MMU registers.

Enjoy your CL!

Monte

[cdmackay]

thanks very much, Monte,

(02-27-2019 12:20 AM)Monte Dalrymple Wrote:  If the random stuff in those MMU locations bothers you (like when you do a PLUG ?IMG ? command to see the MMU contents) just do PLUG EMPT x, where x is 0-3 to clear those MMU registers.

It doesn't bother me, but it certainly confused me, as I was trying to get everything straight in my head (there's a lot to learn). I might do that EMPTy though, just to make it tidy

and thanks for producing such an amazing piece of hardware, and all the software to support it, and to Angel and many others for the utility ROMs too. Lots more to learn here, too.

[rprosperi]

(02-27-2019 12:16 AM)cdmackay Wrote:  Any other "must have" ROMs, for general utility use? Other than the 16C emulator which I am looking forward to trying

I find OSX3 essential (this is a custom version of the best OS extensions from the CCD module) - download and read (even just skim) Angel's excellent manual. Though I don't think I know anyone that uses all the great tricks this ROM provides, everyone that uses it becomes hooked on some of the features. For example, check out the Catalog extensions - once you use CAT-1-G, there is no going back. Also it adds CAT 8-F to catalog the modules in Pages 8-F, etc.

Also, check out "Warp Core" - another helper ROM that provides lots of little goodies rather than a few big programs; these are my favorite kinds of ROMs, and these are 2 of the best.

[cdmackay]

(02-27-2019 02:04 AM)rprosperi Wrote:  

(02-27-2019 12:16 AM)cdmackay Wrote:  Any other "must have" ROMs, for general utility use? Other than the 16C emulator which I am looking forward to trying

I find OSX3 essential (this is a custom version of the best OS extensions from the CCD module) - download and read (even just skim) Angel's excellent manual. Though I don't think I know anyone that uses all the great tricks this ROM provides, everyone that uses it becomes hooked on some of the features. For example, check out the Catalog extensions - once you use CAT-1-G, there is no going back. Also it adds CAT 8-F to catalog the modules in Pages 8-F, etc.

Also, check out "Warp Core" - another helper ROM that provides lots of little goodies rather than a few big programs; these are my favorite kinds of ROMs, and these are 2 of the best.

Excellent! thanks very much Bob.