Are there any EZ80 ADL mode source code examples for CP/M 2.2 or 3 ?

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Aug 4, 2022, 6:23:52 PMAug 4
I'm looking for some examples where the eZ80 ADL mode was used with CP/M 2.2 or 3

Thank you.

Bill McMullen

Aug 4, 2022, 8:27:09 PMAug 4
That's a pretty generalized question and it's unclear whether you're implying a rewrite of CCP/BDOS, a mixed-mode BIOS or mixed-mode applications.

I have CP/M 2.2 versions for my Min-eZ (F91) system and another for the eZ-Tiny (F92/F93). I chose to leave the CCP and BDOS untouched while the BIOS is split into two parts: a minimal Z80 mode part that maximizes room for the allocation vectors and an ADL part that contains interrupt code plus the disk drivers and buffers. I've also written some utilities that operate in mixed mode.

Going back and forth between Z80 and ADL modes can be accomplished in several ways but you should be aware of MBASE changes, both stacks and the MADL implications. For example:

JP.LIL $+5 ; Switch from Z80 to ADL mode
JP.SIS $+4 ; Switch from ADL to Z80 mode

There's also the issue of which assembler to use. Zilog's ZDS assembler can be used as it creates a .HEX file which can be converted to .COM by CP/M's LOAD command. You could also create macros for other CP/M assemblers such as M80.

Aug 5, 2022, 2:15:50 PMAug 5
Hi Bill,
Yes it was a pretty generalized question. I'd be interested in seeing ADL rewites of CCP/BDOS if they exist.

I have used older Zilog eZF91 evaluation boards and wired via SPI dual SD Card readers on one and the other has an 8-bit dual slot CompactFlash reader. I use the evaluation units RS232 ports talk to PuTTy or TeraTerm on my PC as my eZ80 console.

I have CPM2.2 or 3 along with a debugger in Flash memory so it can boot from reset. Also, since I'm using the ZDSII setup I can assemble/debug and load memory at 100h then change the PC to the start of CPM in the flash memory or load a version of CPM into upper ram and switch to that.

I have not coded much in the last year and want to learn more and play with the ADL mode.

If your comfortable sharing your ADL BIOS work I'd love to check it out.

Thank you.

Bill McMullen

Aug 5, 2022, 7:32:47 PMAug 5
I'm not aware of any rewrites of CP/M 2.2 or 3 for eZ80 ADL mode although I haven't looked very hard. There has been an upgrade done for MP/M-II but I don't believe it's widely available. For CP/M 2.2 the possible advantage would be to move the allocation vectors out of the 64K Z80 mode space which has already been done in CP/M 3. ADL mode does incur a penalty by using an extra byte for all memory addresses plus there's also the mode switching instructions.

My approach to CP/M on the eZ80 has been to embed a 2.2 system that boots automatically at power on and uses USB for both power and the two serial ports. This embedded system can be used standalone or as a loader for other systems such as CP/M-3 or MP/M and there is a mechanism in place to update the embedded system without the need for a Smart Cable.

You can contact me via email to discuss code issues.
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