256byteramOkay so it has been quite some time since I've provided an update. I've got good news however. I have at long last got CP/M Plus to boot correctly on my hardware and got it to use bank switched memory.
The disk access speed improvements are significant. That and it's capable of accessing partitions up to 512MB, much more than CP/M 2.2's 8MB limit.
Here are some things I learned about CP/M Plus:
- Digital Research implemented a serial number scheme, where if any of them don't match, the OS will halt. Make sure all binaries come from the same distribution.
- Get it working without bank switched memory first. Even if this means it's working with 34kB free, at least it's working.
- Make sure Disk Parameter Headers and Disk Parameter Blocks are sane. There should be a few vectors before the DPH to tell the BIOS where your routines are. Check the manual.
- Make sure you're selecting the correct bank when reading or writing to the disk.
- The Z80 reserves Reset Vector 0x38 as an interrupt vector (when using Interrupt Mode 1). This causes a lot of incompatibilities with the default CP/M debugger as it uses the same vector as a breakpoint. Use patched copies.
- Place interrupt vectors on all banks when booting and make sure to say the bank starts at page 1 (not page 0) so the BDOS doesn't use it as a buffer.
- If it's not working, it's your fault.
I'll add more as I think of them.
In the meantime, please enjoy this picture:
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Give a try to my CP/M text editor: te.
It's in my github. More info in www.floppysoftware.es
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Have you found a usable plain text editor for CP/M? ED is just horrible, but considering its age that's just to be expected. ;-) I can't get the MIX editor working at all, and while I can use Turbo Pascal 3.0 as a text editor it doesn't feel right - and the arrow keys doesn't work either...
Maybe I need to write my own simple text editor in Z80 asm ^__^
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There's WordMaster which is a bit like vi but by the same people who did WordStar.
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Thanks. I'll give it a go and see if I survive - vi is not really my cup of tea. But it can't be worse than the cp/m ed. ;-)
In currently hacking on a z80 cp/m 2.2 emulator for ESP8266...
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